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Weather Station Hardware => Blitzortung => Topic started by: Cutty Sark Sailor on October 10, 2013, 02:15:27 PM

Title: Interference and Noise
Post by: Cutty Sark Sailor on October 10, 2013, 02:15:27 PM
'Interference': Any undesired signal that tends to interfere with reception.

I thought it time to start a thread that brings all our noise knowledge into one place, especially to help those living with frustration and those who may be less experienced and knowledgeable. Perhaps we could bring our troubleshooting, isolating, and resolution tips here, along with any screen captures we might grab.

Qualification: June 3 2014 Please Note that this looks at H field only, Amplifier 1, channels A (red) and B (green).  Among other difference between E and H fields amps: You CANNOT DISABLE E-field signals by checking "don't send" on the settings page. The server wants to see all three channels. Best you can do is set gains to 1x1, thresholds to "0". You can adjust gains. E field signals look different, and interference location is a different process.

We all want the clearest signal at the maximum distance that supports the network, and - for myself - there is some 'pride' and curiosity involved. We have healthy servings of those, or we wouldn't get involved it this! Contra-wise, we also want to avoid hindering the network efficiency by ignoring 'nearby' signals... especially as more stations come online in the USA. Our 'long range'  capability becomes less a factor, and clean signals become more important... not ignoring the heavier load on the servers due to mucho 'noise' signals.

The first phase would be to identify, if we can, the type and source of interference. And that becomes quite a chore sometimes.


Addenda, May 2015
...these thoughts:
While communicating with some operators, I developed a sense that some of us might be
confused when we speak of "interference" and "interference".... :D
We might be using "interference" as 'a disturber or noise that degrades communication or data, or a system's operation'.
But we might also simply be referring to "a system going into 'interference' ".

System RED (and BLUE will likely operate in a similar manner) will go into one of two types of "Interference Modes" from time to time.  "Burst" or "Normal"
The System is designed this way, generally,
1. Because nearby active cells produce so many signals, so rapidly, that they cannot normally be recognized separately... and matter of fact, one "paradigm" of the developers might be phrased as "detected signals <30km are generally useless to the network"  with the current design, anyway.
So when you go interference because of nearby storms.... accept it, let 'er ride, and let the network do its net work.  :D
2. Unless you have a perfect location, sporadic 'disturbers' such as an arcing power line, may produce conditional interference that swamps the controller similar to nearby cells, such are useless anyway.  But they're sporadic, and when they cease, you'll come out of interference.
3. Repeating, identical, signals that might be caused by someone standing nearby with walkie-talkie, burst of repeating  power line noise... weird stuff.

Now, while Interference Modes can be triggered by non-lightning signals,  it is based on the "number of signals sent" within certain time frames.
Except for the limited 'repetition and recurring' algorithms for "Burst Mode", it has no recognition of "types of signals" and doesn't care.
Interference mode can be activated due to signals on all channels, or one single channel, or a combination if you're running 5 channels including both H and E field.

It also is one 'controller parameter' that is monitored over time and varied by the server/controller! 
In other words, the server/controller can lower or raise those limits depending on what it sees from your station! 
You only have "indirect control' of this response: your operating mode, gains and thresholds, etc.
The 'basic' purpose is to avoid sending "too many signals" or "EM noise pulses" from your station.

These "interference parameters" operate no matter what mode you're in -Auto or Manual: 

If you look at your 'status' page when you access your controller web interface, down under "other parameters', you see something like this:
Interference Mode
   Burst        When > 80sig/s in 3s average. Disable when 50% below threshold
   Normal     When > 70sig/s in 60s average. Disable when 30% below threshold

...and if too many signals are actually sent under certain conditions,
that will 'back that down' to, for e.g. 30sig and 15sigs.... until
you can come out of interference, and the limits will rise again after some period of time.

So if over "some period of time" you've averaged over 70sigs/minute, you'll go into "Normal" interference, and stay there until it drops below 70sigs average.... which can be a long time... especially if the /controller has lowered the max limit temporarily for your controller to 15...! And if you are in Auto mode it could take even longer under certain conditions, as the controller may continuously cycle on and off and in and out of the mode.

For Burst mode... (short periods of repeating signals) it'll come out of interference much quicker.. a few seconds). It can be longer, again, if your limits have been temporarily lowered...

Remembering that you have only indirect control over 'Interference Mode" ... each channel's 'gain and threshold' settings.
If you're in "Automatic" mode, you have no access to your gains and threshold settings. Unless you desire to wait until the sources vanish on their own, you'll have to return to "Manual" mode, and reapply gain/thresholds settings under each specific amp, (the actual gains /thresholds have been set by "Auto", and they are NOT visible under the AMP settings... that shows you your settings so you must hit apply to reset the "Auto" parameter.
It follows, then, that if H channel A is the one causing the interference, you could back down channel A to 'just under noise trigger level, it will now come out of interference, and channel B  continues its merry way, and A now is of some use also.
You can take it from here.

(This is duplicated at http://sferics.us/bo1/index.php?topic=130.0 for cross searching )


I'll kick it off with the following posts....

Mike

Links to explore:
RFI GUIDE (http://frankfortweather.us/blitzblitz/rfiguide1.pdf) From New Zealand, a PDF... pages 1 through 9 have good info!
Radio Jay Allen's Web Page (http://radiojayallen.com/combatting-am-and-sw-interference/) or Download as PDF  (http://frankfortweather.us/blitzblitz/rfiguide2.pdf) A thorough, simple look-see, although aimed at AM broadcast, it's very applicable, and not technical.
Title: The cleanest signals we can obtain?
Post by: Cutty Sark Sailor on October 10, 2013, 02:16:06 PM
Idealized Waveforms:
(http://frankfortweather.us/blitzblitz/ideal1.jpg)
(http://frankfortweather.us/blitzblitz/ideal2.jpg)
System Red Received Examples:
(http://frankfortweather.us/blitzblitz/1 a clean signal.jpg)
(http://frankfortweather.us/blitzblitz/2 a clean signal 1.jpg)
(http://frankfortweather.us/blitzblitz/3 a clean signal 2.jpg)
(http://frankfortweather.us/blitzblitz/4 a clean signal 3.jpg)

And if we've constructed well, are fortunate, in a good location, with adequate antennas, we should acquire strokes and signals similar right from the start.

But not always....

-more-
Title: That Power Line Stuff
Post by: Cutty Sark Sailor on October 10, 2013, 02:16:47 PM
Our good old American 60hz:
(http://frankfortweather.us/blitzblitz/5a 60hz .jpg)

And it often has other noise mixed with it, in this case from an Acer desktop:
(http://frankfortweather.us/blitzblitz/5b 60hz with computer.jpg)

Also signals ride in on it:
(http://frankfortweather.us/blitzblitz/5c 60hz with signal.jpg)
(http://frankfortweather.us/blitzblitz/5d 60hz with signal.jpg)

And now, we have 60hz, computer leakage, and signals...

But wait!   There's more!   

Moving on to computer noise!
Title: Computer Noise
Post by: Cutty Sark Sailor on October 10, 2013, 02:17:32 PM
When we first combine our antennas, amp, and controller, into 'The System',  we may in fact be sitting right next to our pc, laptop or whatever...and our new Blitzortung system  immediately goes into interference, with a signal screen that looks similar to this:
(http://frankfortweather.us/blitzblitz/21 computer 2.jpg)
Or the noise might be a lower level, with signals visible:
(http://frankfortweather.us/blitzblitz/22 computer 3 with signal.jpg)
The above 2 images result from an HP Laptop 5 and 10 feet distant from the antennas.

The below contain interference from a leaky ACER desktop, in another room, 25' away! About 5' from the controller and it's cables:
(http://frankfortweather.us/blitzblitz/23 computer 1.jpg)
And here's a signal riding in on it:
(http://frankfortweather.us/blitzblitz/24 computer mixed with signal 1.jpg)

Now, take a piece of wire, connect it to the computer case (metal, hopefully) and ground it to the controller!
(http://frankfortweather.us/blitzblitz/25 mixed with signal 2 grounded case.jpg)
Well, that was simple enough. Now it may be tolerable.

Now what is this?
(http://frankfortweather.us/blitzblitz/26 computer mixed sith signal and sodium grounded case.jpg)
At the far right, what appears to be a signal from a streetlight!  Sodium or Mercury vapor?... and they'll put you in interference in a jiffy!


Possible Quick Resolutions: 1) Have you grounded the Controller per the documentation? 2) Move the antenna and amp well away from the computer room if possible! 3) Try grounding the metal PC case. Measure any voltage difference between case and the controller's ground first! Use a high impedance meter...

-more-
Title: External Utility Noise, Possibly
Post by: Cutty Sark Sailor on October 10, 2013, 02:18:08 PM
Power Lines and stuff (anything that arcs, for example, an insulator, transformer, etc) might look like this:
(http://frankfortweather.us/blitzblitz/31 sodium or mercury 2.jpg)
a flurry of spikes, and that slow '60Hz' or even '120Hz curve'...  probably intermittent... if it's a street light, you'll note it just at dusk when it tries to fire, and sporadically throughout the dark hours, until sometime after sunrise...
(http://frankfortweather.us/blitzblitz/32 sodium or mercury.jpg)
It may be riding on other noise:
(http://frankfortweather.us/blitzblitz/33 computer mixed with sodium 2.jpg)
(http://frankfortweather.us/blitzblitz/34 computer mixed with sodium 1.jpg)
Any arcing device may look similar... power drills, sanders... etc  etc


Possible Quick Resolutions: 1) If you've isolated it to a street light, the power company, city, or other utility or factory is responsible. In some areas the Property Owner has to make the complaint. Tell 'em there's a street light/security light failing. Could also tell 'em it's interfering with your late night A.M. Talk Radio program reception... You've got the FCC on your side. But not necessarily for lightning detector interference! More importantly, tell 'em if you're pretty sure it's a transformer or insulator... you don't won't to be powerless during cold weather! (Or hot, for that matter)... .

-more-
Title: Automobiles, Power Tools, Other Noisy Stuff.
Post by: Cutty Sark Sailor on October 10, 2013, 02:19:04 PM
(http://frankfortweather.us/blitzblitz/44 car ignition spike.jpg)
May resemble a 60Hz line noise, depending on engine etc!

(http://frankfortweather.us/blitzblitz/45 car engine computer and signal.jpg)
What a hodge-podge!

Possible Quick Resolutions: 1) Patience, it'll drive off, ...or run out of fuel.

Then your neighbor fires up his electric drill, or similar:
(http://frankfortweather.us/blitzblitz/drill.jpg)

Or your energy conscious Green spouse replaces the last 100W incandescent light bulb in the US
with a 13 W fluorescent:

(http://frankfortweather.us/blitzblitz/13W Fluor.jpg)
Yes, resembles computer and other similar interference, doesn't it?

Possible Quick Resolutions: 1) Borrow your neighbor's drill. Forget to return it.  2) Paint your face green and claim extreme fatigue and nausea resulting from Mercury radiation poisoning due to the fluorescent, and replace it with a 75 watter...



Hope these initial blurbs help.... post your experience, screen grabs and tips!

Couple of folks had some issues with those robot lawn mowers.... the 'perimeter' radio guidance.  Solutions varied from waiting till grass out of season, giving wife a non-motorized reel mower, ... and I suggested a herd of sheep instead, since they're self-supporting, self-replicating, keep the grass cut short, fertilize it, and provide warm snuggly stuff for cold weather....

Same is true for those electronic "pet fences". Seems like both resemble the 'computer interference' images somewhat.

Mike





Title: Re: Interference and Noise
Post by: Timay on October 10, 2013, 02:49:48 PM
Take a shot of the signal after someone turns on a plasma TV...I think you will be amazed.  I had a plasma TV for about a week and then took it back.  When the TV was on, it completely wiped out my HF ham radio.

Tim
Title: Re: Interference and Noise
Post by: i_fiorentino on October 10, 2013, 02:59:12 PM
Wow Mike, thanks for sharing this!

Please, Could you give me an eye to my signal to verify if it's apparently ok?

Here it is: https://www.dropbox.com/s/9gikltg3lpj6383/Signal1.PNG

I also posted the image below.....what meaning this message near the captured strike?

https://www.dropbox.com/s/3vixc4afjizu6ie/Strikes.PNG

Many thanks,



Alessandro
Title: Re: Interference and Noise
Post by: Jumpin Joe on October 10, 2013, 03:04:15 PM

'Interference': Any undesired signal that tends to interfere with reception.

I thought it time to start a thread that brings all our noise knowledge into one place, especially to help those living with frustration and those who may be less experienced and knowledgeable. Perhaps we could bring our troubleshooting, isolating, and resolution tips here, along with any screen captures we might grab.

We all want the clearest signal at the maximum distance that supports the network, and - for myself - there is some 'pride' and curiosity involved. We have healthy servings of those, or we wouldn't get involved it this! Contra-wise, we also want to avoid hindering the network efficiency by ignoring 'nearby' signals... especially as more stations come online in the USA. Our 'long range'  capability becomes less a factor, and clean signals become more important... not ignoring the heavier load on the servers due to mucho 'noise' signals.

The first phase would be to identify, if we can, the type and source of interference. And that becomes quite a chore sometimes.


I'll kick it off with the following posts....

Mike


Mike, I think this is a fantastic idea.

I know it will help me.

Joe
Title: Re: Interference and Noise
Post by: miraculon on October 10, 2013, 03:06:41 PM
I like it. Kind of a "rogues gallery" of noises.

I'll post my bad ones here when they occur.

Greg
Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on October 10, 2013, 04:38:45 PM
Wow Mike, thanks for sharing this!

Please, Could you give me an eye to my signal to verify if it's apparently ok?

Here it is: https://www.dropbox.com/s/9gikltg3lpj6383/Signal1.PNG

I also posted the image below.....what meaning this message near the captured strike?

https://www.dropbox.com/s/3vixc4afjizu6ie/Strikes.PNG

Many thanks,



Alessandro
I don't know for sure, Alessandro, those signals look pretty clean... for the error message, you might check the 'settings' 'sampling' for 'tracker'...
the settings should be  512   128  and some percentage... mine's set for 30%, and under 'A/D Converter'  56   28  12bits  and 2.   That might be what's happening.
Mike
Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on October 10, 2013, 04:43:45 PM
Take a shot of the signal after someone turns on a plasma TV...I think you will be amazed.  I had a plasma TV for about a week and then took it back.  When the TV was on, it completely wiped out my HF ham radio.

Tim
Yeah, Tim. I had a recent spurt of interference that looked very similar to the computer interference. I think was about 55-56Khz. Neighbor next door had just moved their big plasma to an outside wall, facing my garage. Negotiated a slight movement of the TV to the corner of their room, now minimal interference, but still some on rare occasions.
Title: Re: Interference and Noise
Post by: NeverDie on October 10, 2013, 05:02:31 PM
'Interference': Any undesired signal that tends to interfere with reception.

I thought it time to start a thread that brings all our noise knowledge into one place, especially to help those living with frustration and those who may be less experienced and knowledgeable. Perhaps we could bring our troubleshooting, isolating, and resolution tips here, along with any screen captures we might grab.

We all want the clearest signal at the maximum distance that supports the network, and - for myself - there is some 'pride' and curiosity involved. We have healthy servings of those, or we wouldn't get involved it this! Contra-wise, we also want to avoid hindering the network efficiency by ignoring 'nearby' signals... especially as more stations come online in the USA. Our 'long range'  capability becomes less a factor, and clean signals become more important... not ignoring the heavier load on the servers due to mucho 'noise' signals.

The first phase would be to identify, if we can, the type and source of interference. And that becomes quite a chore sometimes.


I'll kick it off with the following posts....

Mike

Links to explore:
http://radiojayallen.com/combatting-am-and-sw-interference/ (http://radiojayallen.com/combatting-am-and-sw-interference/) A thorough, simple look-see, although aimed at AM broadcast, it's very applicable, and not technical.


Thanks for the helpful info.  What is it that you're using to capture the signals and make those nice signal and noise graphs?
Title: Building Structure and Antenna Placement
Post by: Cutty Sark Sailor on October 10, 2013, 05:06:45 PM
I posted a link, and guess we can post more, to a page regarding intereference... maybe move all the links to the first post as you post 'em.  Anyway, he mentions building structure, and discusses the blocking of signals.

I have the opposite issue in this dwelling. The home is covered with (real) foil covered insulation. The encapsulation seems to act as a 're-radiator' for noise... matter of fact, I've only found one 'sweet spot' in the garage where the generated fields are weakest... and one spot only!...

A few weeks ago, I rolled up a couple of 300mm ferrites per Don F's 250mm design, and replaced my 120mm, shielded kit ferrites with them. Possibly because of the increased gain, this longer pair has a better S/N than the 120s overall. And they perform better unshielded.

Antenna type, placement and orientation is important for some types of interference. For e.g. If I only had one source of street light interference, instead of three right now, with this TOA system not directionally critical, I could 'null' one antenna by pointing its 'core' end directly toward the light. However, with the current trinary source and the radiating home shell, that has very little effect. The stronger fields are pretty much detected from 'all directions'.  
Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on October 10, 2013, 05:09:36 PM
What is it that you're using to capture the signals and make those nice signal and noise graphs?
Those are just screen captures of the signals display of the web interface for the Blitzortung controller. Nothing dramatic or fancy at all.
Title: Re: Interference and Noise
Post by: miraculon on October 10, 2013, 08:56:19 PM
OK, here is one that I just captured. I see this all the time. I call it the Two-Horn noise because it looks like it has horns (or maybe ears).

This is one of the nasty ones, it just started all of a sudden.

Greg
Title: Re: Interference and Noise
Post by: Jumpin Joe on October 10, 2013, 09:03:29 PM
OK, here is one that I just captured. I see this all the time. I call it the Two-Horn noise because it looks like it has horns (or maybe ears).

This is one of the nasty ones, it just started all of a sudden.

Greg

Greg, I see this occasionally too!
Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on October 10, 2013, 09:49:47 PM
OK, here is one that I just captured. I see this all the time. I call it the Two-Horn noise because it looks like it has horns (or maybe ears).

This is one of the nasty ones, it just started all of a sudden.

Greg
That looks like a sodium/mercury light! If I can catch one of mine acting like that, we can compare. On both antennas, out of phase! Check the diagonal directions. Weather's cooler, it's having trouble starting.
Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on October 10, 2013, 10:28:35 PM
OK, here is one that I just captured. I see this all the time. I call it the Two-Horn noise because it looks like it has horns (or maybe ears).

This is one of the nasty ones, it just started all of a sudden.

Greg
That looks like a sodium/mercury light! If I can catch one of mine acting like that, we can compare. On both antennas, out of phase! Check the diagonal directions. Weather's cooler, it's having trouble starting.
Here ya go...
(http://frankfortweather.us/blitzblitz/street-lights.jpg)
5 mins apart, virtual twins, not as strong as yours, and not as much 60Hz rollout, but that's a 10 yr old utility pole sodium security light 200' SE of my antennas....
Title: Re: Interference and Noise
Post by: gwwilk on October 11, 2013, 09:59:38 AM
Great thread.  Thanks, guys.  This is an essential primer for analyzing and defeating those pesky noise problems we can all experience.  I just noticed a streetlight interference pattern on one of my strikes, and I still have 60 Hz interference coming and going on channel B.  I need to go over that side of my amplifier board again...
Title: Interference and Noise - added resource link to Post 1
Post by: Cutty Sark Sailor on October 11, 2013, 11:32:21 AM
Resource Summary to date... see Post #1 (http://www.wxforum.net/index.php?topic=20439.msg196598#msg196598) for most up to date additions/changes

Links to explore:
RFI GUIDE (http://frankfortweather.us/blitzblitz/rfiguide1.pdf) From New Zealand, a PDF... pages 1 through 9 have good info!
Radio Jay Allen's Web Page (http://radiojayallen.com/combatting-am-and-sw-interference/) or Download as PDF  (http://frankfortweather.us/blitzblitz/rfiguide2.pdf) A thorough, simple look-see, although aimed at AM broadcast, it's very applicable, and not technical.
Mike
Title: Re: Interference and Noise
Post by: schwab on October 11, 2013, 05:13:51 PM
I have an ungrounded and unshielded ferrite antenna 6.8 system.

Is the attached image a reasonable signal profile?
Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on October 11, 2013, 06:00:34 PM
I have an ungrounded and unshielded ferrite antenna 6.8 system.

Is the attached image a reasonable signal profile?

Something doesn't look right. I'm not familiar w/greens, but:
Is 256 the default sampling rate for Green systems, not 512???, and  0 sample before trigger?  Zero Gain???
Title: Perfect Signals?
Post by: Cutty Sark Sailor on October 11, 2013, 07:36:33 PM
For comparison, added drawings of 'idealized' signals to post #2 above (http://www.wxforum.net/index.php?topic=20439.msg196599#msg196599)
Mike
Title: Re: Interference and Noise
Post by: miraculon on October 11, 2013, 08:23:10 PM
I have an ungrounded and unshielded ferrite antenna 6.8 system.

Is the attached image a reasonable signal profile?

Something doesn't look right. I'm not familiar w/greens, but:
Is 256 the default sampling rate for Green systems, not 512???, and  0 sample before trigger?  Zero Gain???

The Green (6.8USB) uses a "dumb" amplifier. The gains are set by jumpers (a pain, believe me) and not PGA (Programmable Gain Amplifier). The windows-based tracker program has no idea about the gain setting. The threshold on a stock "green" is fixed at +/-417mV, although my modded unit is adjustable. The tracker doesn't know what this is set to either, the "green" controller uses a simple analog comparator that triggers based on a reference voltage.

Also the scope-like trigger window is different hence the different trigger points. I believe that the buffer can store the pre-trigger data in "red".

Here is a web page where I have both of my stations "red" and "green". I also have the FFT plots for both systems.

http://www.miraculon.net/signals.html (http://www.miraculon.net/signals.html)

Greg

Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on October 11, 2013, 08:28:11 PM
I have an ungrounded and unshielded ferrite antenna 6.8 system.

Is the attached image a reasonable signal profile?

Something doesn't look right. I'm not familiar w/greens, but:
Is 256 the default sampling rate for Green systems, not 512???, and  0 sample before trigger?  Zero Gain???

The Green (6.8USB) uses a "dumb" amplifier. The gains are set by jumpers (a pain, believe me) and not PGA (Programmable Gain Amplifier). The windows-based tracker program has no idea about the gain setting. The threshold on a stock "green" is fixed at +/-417mV, although my modded unit is adjustable. The tracker doesn't know what this is set to either, the "green" controller uses a simple analog comparator that triggers based on a reference voltage.

Also the scope-like trigger window is different hence the different trigger points. I believe that the buffer can store the pre-trigger data in "red".

Here is a web page where I have both of my stations "red" and "green". I also have the FFT plots for both systems.

http://www.miraculon.net/signals.html (http://www.miraculon.net/signals.html)

Greg


So Greg, your're saying that SCHWAB's signal looks fine... right???
Title: Re: Interference and Noise
Post by: miraculon on October 11, 2013, 08:36:56 PM
It would seem so. At least as far as "gain" and sample rate info is concerned. I looked over at Blitzortung.org for a mention about the differences between red and green in the gain and sampling windows, but I can't seem to find it.

Greg
Title: Re: Interference and Noise
Post by: schwab on October 12, 2013, 08:24:32 AM
What I am trying to find out is if my Green 6.8 system will be optimized and benefit from Miraculon's input terminator mod or not.

I am happy to post additional images although lightning activity is low at the moment.

Thanks for your expertise, time and consideration for this electrical novice.


Title: Re: Interference and Noise
Post by: miraculon on October 12, 2013, 11:00:12 AM
What I am trying to find out is if my Green 6.8 system will be optimized and benefit from Miraculon's input terminator mod or not.

I am happy to post additional images although lightning activity is low at the moment.

Thanks for your expertise, time and consideration for this electrical novice.


I have actually modified the mod, so to speak. I changed to a 10K resistor for the terminator. If you make it as I did with a jumper, you can plug it in and out easily. If you need the part number on Mouser for the 2-pin socket with solder tabs, let me know and I will post it here. If you get several of the sockets, you can make up a variety of terminator values. e.g. 2.2K, 5K, 10K, etc. to experiment with.

I also set the filters to the 34KHz settings. The 17KHz filter settings were a way to deal with the resonant peak of the ferrite antennas. By adding the terminator resistors, the resonance is reduced so the bandwidth can be opened up. Red has wider bandwidth than Green. I was trying to mimic the Red system configuration as much as possible.

The effective output of the antenna will change, so you will need to re-adjust your gains accordingly.

Remember to set the input to "single ended" with jumper IA-3 and IB-3 in addition to adding the terminators. Otherwise, the jumper resistance will not be across the input. Changing to single-ended was the best noise countermeasure that I did. "Red" went to single ended. There was simply too much common-mode noise voltage for the differential input to cope with.

Greg
Title: Re: Interference and Noise
Post by: i_fiorentino on October 12, 2013, 07:25:18 PM
Hi guys,
i've solved most of my noise issues.....it was my power line!
But it remains a light fluctation like the image below:

https://www.dropbox.com/s/p4m6y4vsa5hbtur/Cattura2.PNG

OR

https://www.dropbox.com/s/el5eh2klkia949b/Cattura3.PNG


I've tried to turn off my emergency light, pc, tv lcd, decoder sat, my boltek antenna, lap top, sat signal extender, all my kitchen appliances ecc.ecc. without lucky.
I'm beginning to lose hope :(
My actual settings: https://www.dropbox.com/s/2ti5phwpmtxf2bz/Cattura5.PNG
Thanks in advance for any help or advice!
Regards,


Alessandro
Title: Re: Interference and Noise
Post by: miraculon on October 12, 2013, 08:15:31 PM
Alessandro,

In my opinion with 20cm ferrite antennas, your gain is too high and your thresholds are too low.

I would try reducing gain. Your product of 10x16x40 = 6400, is very high.

Channel A Gain [10] [16]
Channel A Gain [10] [16]

(x 40 is not a user setting)

I would reduce it to some combination that gives a gain in the range of 1000-2000. You could try 5x5x40=1000 as a starting point. Also, if you find a good combination, make the first number the larger one. For example, if you use a gain of "1280" use something like 8x4x40, not 4x8x40. (the "40" is the fixed gain that you cannot control).

Also, the threshold of 76mV is too aggressive. Try the default 120mV or even 200mV.

Once you stabilize to "Normal" instead of interference mode, you can then try lower thresholds and higher gains. You need to make gradual changes. Don't be surprised if you get a good "Normal" mode for hours or even days, and interference mode comes back if some kind of new noise appears.

Greg
Title: Re: Interference and Noise
Post by: i_fiorentino on October 13, 2013, 02:35:09 AM
Alessandro,

In my opinion with 20cm ferrite antennas, your gain is too high and your thresholds are too low.

I would try reducing gain. Your product of 10x16x40 = 6400, is very high.

Channel A Gain [10] [16]
Channel A Gain [10] [16]

(x 40 is not a user setting)

I would reduce it to some combination that gives a gain in the range of 1000-2000. You could try 5x5x40=1000 as a starting point. Also, if you find a good combination, make the first number the larger one. For example, if you use a gain of "1280" use something like 8x4x40, not 4x8x40. (the "40" is the fixed gain that you cannot control).

Also, the threshold of 76mV is too aggressive. Try the default 120mV or even 200mV.

Once you stabilize to "Normal" instead of interference mode, you can then try lower thresholds and higher gains. You need to make gradual changes. Don't be surprised if you get a good "Normal" mode for hours or even days, and interference mode comes back if some kind of new noise appears.

Greg


Greg,
thanks a lot for your kind support!
What about signal? (image on the post above)

In your opinion is it normal that ondulation?
Or it could compromised the detection of lightning by the antennas?
Thanks again.
Regards,


Alessandro

Title: Re: Interference and Noise
Post by: miraculon on October 13, 2013, 11:50:30 AM
I am not sure what that is, or what the source might be. It appears to be about 1000usec between peaks. This works out to 1milli-sec and corresponds with a 1Kilo-Hz signal.

Did you try disabling the PWM backlight dimming on the display? I don't remember what frequency that runs at, but I saw noise due to the display. I set my PWM to 100%, then 0% after 60 seconds.

Also with the huge gain you had, it is very susceptible to a variety of noises. Is it still there with lower gain settings?

Greg
Title: Re: Interference and Noise
Post by: scarecrow93 on October 13, 2013, 06:31:16 PM
Add Synology NAS to the list.

I've been getting this signal for awhile now but haven't been able to isolate it until today.

The NAS is located 10-15 feet from the antennas (through walls...etc).  Turn the NAS off and it's gone.

(http://www.weathergeek.org/lightning/images/antenna/synologyinterference.png)

Lance
Huntingtown, MD
Title: Re: Interference and Noise
Post by: miraculon on October 13, 2013, 06:56:56 PM
Here is one that I encountered today. I was running high gain (1600) all day, then this suddenly started. I took the Cornet Micro sniffer out and there was a magnetic field to the south side of the house. Don't know what it was though.

Greg
Title: Re: Interference and Noise
Post by: i_fiorentino on October 30, 2013, 12:33:23 PM
Hi guys,
i've attached some images about a possible noises.
Please, could you give me an eye?
What about this noises in your experience?
Should be shielded the cable that goes from the controller to the antennas?

(http://imageshack.us/a/img28/8420/3i9k.png)
(http://imageshack.us/a/img42/2594/6i4t.png)
(http://imageshack.us/a/img853/5801/z53y.png)
(http://imageshack.us/a/img18/2202/gnhp.png)
(http://imageshack.us/a/img689/5922/kxur.png)
(http://imageshack.us/a/img5/7518/u3f1.png)
(http://imageshack.us/a/img547/1576/4olw.png)

Thanks in advance.
Regards,


Alessandro
Title: Re: Interference and Noise
Post by: miraculon on October 30, 2013, 09:12:49 PM
Quote
Should be shielded the cable that goes from the controller to the antennas?

Yes, use STP CAT5, Shielded for the antenna/controller connection. I gave this advice previously:
http://www.wxforum.net/index.php?topic=20424.msg196452#msg196452

Greg


Title: Re: Interference and Noise
Post by: fotogw on November 05, 2013, 01:42:54 PM
Hey all,

Great thread!

Got 2 screenshots of confirmed interference.
- picture 1 is an electric fence at approximately 100 meters distance to the antennas. Occurs ~1x per sec., can be heard clearly by a small AM-radio.
- Picture 2 is the controller LCD @60% brightness. This slow rising and falling of the signal stops when the brightness is set at either 0% or 100%.

Gerhard


Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on November 05, 2013, 02:39:15 PM
Good addition, Gerhard!   Thanks... maybe we'll actually fill Greg H's 'rogues gallery' with evil emis.... !  I was especially interested in the NATO Submarine signals at 23.5kHz in the BT thread...  :lol: 
Title: Re: Interference and Noise
Post by: scarecrow93 on November 05, 2013, 06:24:23 PM
Here's something new!  About 3 days ago, I started getting this signal.

It runs at 120Hz (measured on a non-lightning day).  It's pretty steady in amplitude and cycle.  It runs all day without any breaks.  I know it's not the antennas or system.  I can rotate the antennas and the signal moves to the other side.  I've turned off and unplugged almost everything I can get to in my house trying to isolate it with no luck.  I've relocated the antennas a couple of times and it follows.

So far,  I've compensated by moving the entire interference over to channel B and raising the trigger level to just above the interference peak.  I've seen whenever a strike happens, it'll still raise the amplitude of the signal just enough to trigger.

Any guesses what this is?

Thanks!

Lance
Huntingtown, MD  #724
Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on November 05, 2013, 07:16:13 PM
Here's something new!  About 3 days ago, I started getting this signal.

It runs at 120Hz (measured on a non-lightning day).  It's pretty steady in amplitude and cycle.  It runs all day without any breaks.  I know it's not the antennas or system.  I can rotate the antennas and the signal moves to the other side.  I've turned off and unplugged almost everything I can get to in my house trying to isolate it with no luck.  I've relocated the antennas a couple of times and it follows.

So far,  I've compensated by moving the entire interference over to channel B and raising the trigger level to just above the interference peak.  I've seen whenever a strike happens, it'll still raise the amplitude of the signal just enough to trigger.

Any guesses what this is?

Thanks!

Lance
Huntingtown, MD  #724
Hey, Lance... probably not in your house.

1. Which direction is B picking signal up/ E-W or N-S  ?
2. Is it daylight only, or 24/7 ?

If your 'member map' pin is close to actual site:
You've got some rather big power lines,  a school, just north, and businesses to the NNW, etc on the map. What're the businesses?
Title: Re: Interference and Noise
Post by: i_fiorentino on December 02, 2013, 11:44:13 AM
Hi guys,
i've tried all solutions but without any lucky.
This noise: https://www.dropbox.com/s/tvzqs4ybhayiod2/Screenshot_2013-11-30-08-59-47.png is always present, ALWAYS!
It's repeated continuosly every 10/15 seconds.
I've also tried to move the antenna location at my parent's house....nothing!
This noise was still present.
At this point, i don't know how could it be.
My actual gain is 5*5 and trigger to 65mv but lightning detection is too poor....a near station (Scandicci) detects four times more than mine.
I've no other ideas.
If you would i could give you User and Pass to my Blitzortung panel.
Regards,


Alessandro
Title: Re: Interference and Noise
Post by: tobi on December 08, 2013, 03:07:00 AM
This noise: https://www.dropbox.com/s/tvzqs4ybhayiod2/Screenshot_2013-11-30-08-59-47.png is always present, ALWAYS!
This noise comes from the data transmission to the LCD. You can eliminate it, by disabling the whole display ("LCD Auto Off" option in the settings). There are other noise sources which can not be disabled, but their amplitudes are not so high. As long as your threshold values are at least ~100mV, you shouldn't see the noise. There's no need to go much lower here. Such digital noise is an disadvantage of the current piggyback solution with the STM32F4Discovery.
Title: Re: Interference and Noise
Post by: i_fiorentino on December 08, 2013, 12:35:30 PM
This noise: https://www.dropbox.com/s/tvzqs4ybhayiod2/Screenshot_2013-11-30-08-59-47.png is always present, ALWAYS!
This noise comes from the data transmission to the LCD. You can eliminate it, by disabling the whole display ("LCD Auto Off" option in the settings). There are other noise sources which can not be disabled, but their amplitudes are not so high. As long as your threshold values are at least ~100mV, you shouldn't see the noise. There's no need to go much lower here. Such digital noise is an disadvantage of the current piggyback solution with the STM32F4Discovery.

Wow, great news!
But if i disable display LCD the amp and antennas still works?
Thanks,

Alessandro
Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on December 08, 2013, 01:20:10 PM

But if i disable display LCD the amp and antennas still works?
Thanks,

Alessandro
Sure... they'll work fine.  ;)
Mike
Title: Bah Humbug
Post by: Cutty Sark Sailor on December 09, 2013, 09:13:33 AM
Neighbors' Outdoor Flashing Christmas Lights:  ;) Rudolph will probably burn out the system on Christmas Eve....
Be nice if they'd just turn 'em off during daylight every day, also...
Title: Re: Interference and Noise
Post by: miraculon on December 09, 2013, 10:48:57 AM
I have been pondering  :-k on whether to request that the Blitzortung guys (Tobi or Egon, not sure who does it) add the "filters" or adjust the thresholds remotely.
I particularly think that I should do this for the "green" 6.8USB system (now running on OpenWrt).
Has anyone requested filters/thresholds from them? How did it work out and what did they do?
I have seen that they added a specific filter for the robot-sheep (lawnmowers) over on the Blitzortung.org forum.

Greg

Update: got an answer back on this. It won't help my situation.
Title: Re: Interference and Noise
Post by: miraculon on December 17, 2013, 07:58:09 PM
I had a crazy big noise tonight affecting both RED and USB6.8(Green). The Green system (north end w/ferrites) was far worse. I was able to adjust the gain down a bit on RED (south end with big loops) using my bookmarked "presets".

Here is the Green tracker output (OpenWrt) showing almost rail-to-rail amplitude noise. Even with my adjustable threshold set to >1.5Vpk-pk I couldn't get rid of it (+/-750mV). Then all of a sudden it stopped and I was able to reset the threshold to normal.

Greg
Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on December 17, 2013, 11:45:50 PM
It's Holiday time, cold weather, and strange things are happening. I've had similar signals, with a delay difference between A&B channels! Weird. Whatever mine is, I believe it to be ground conduction, for some reason, rather than air, or it's a discharge moving down a power line. Like your's, they're very strong.
I''ve had a couple of days/nights with the amps virtually biased off.

Mike
Title: Re: Interference and Noise
Post by: miraculon on December 18, 2013, 09:40:32 AM
I have a LED bulb running on an X10 module. Even though it wasn't dimmed, the AM radio (~530KHz) was buzzing pretty good around a wire in the bedroom where the GREEN is in the closet.
Placing the AM radio close to the LED bulb, it was very strong. However, when I shut it off, the noise on the tracker was unchanged. So "that wasn't it". The mag field was reading higher than normal on the Cornet electro-smog meter during this noise.

I seem to keep finding a lot of "not it" noises.... ](*,)

Greg
Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on December 18, 2013, 10:03:29 AM
'''
I seem to keep finding a lot of "not it" noises.... ](*,)

Greg

'...when you have eliminated all which is impossible,
then whatever remains, however improbable, must be the truth.' S. Holmes  :-({|=
Title: Re: Interference and Noise
Post by: i_fiorentino on December 28, 2013, 03:44:42 AM
Hi everybody,
i've recorded last lightning on 20 December....after that date only false signals.

My settings are:

Gain 10*10*40
Trigger set to 65mv

This is my regular signal (with Limit Voltage (Y) set to 20%):

(http://i.imgur.com/3naksjk.png)

and these are two (false) signals:

(http://i.imgur.com/gSKef7r.png)

(http://i.imgur.com/YKMqxPO.png)

(http://i.imgur.com/2EhBib4.png)

Is it possible an assembly error?

....and last one. Is there a possibility to erase the interference in the white circle?

(http://i.imgur.com/K7i5oJE.png)

Thanks in advance.
Regards,


Alessandro
Station ID #800
Title: Re: Interference and Noise
Post by: miraculon on January 12, 2014, 10:13:29 AM
Update: (this just in...)

The "Big Ugly Noise" just started on "Green" USB6.8. I went for a little stroll on the sidewalk. I noticed my next door neighbor on the north side watching his big screen TV. As I passed the same end of his house as the TV, the buzz heard on the WR3 VLF receiver got really strong. I will have to ask him sometime if it is a plasma, but I bet that it is. This neighbor is closest to the  "Green" detector's antennas.

Greg



I just received one of these VLF receivers from Stephen P. McGreevy. It is really sensitive, there are all kinds of noises in the house that I pick up with it. Since this is the same "band of interest" as Blitzortung, I think that it will be more effective than the Cornet meter or the AM radio.
I also found a reasonably quiet area in the driveway that I could hear the lightning off of the East Coast yesterday and again this morning.

I really want to hear some of the "whistlers"....

http://www.auroralchorus.com/wr3gx2.htm (http://www.auroralchorus.com/wr3gx2.htm)

The receiver is well made with a metal housing and includes the antenna. I plan on using it to see if my new house candidates are quieter than here. (How's that for being off the deep end? Sorry, Dear. We can't buy this house because there is too much noise.) :shock:

Greg
Title: Re: Interference and Noise
Post by: miraculon on February 16, 2014, 04:15:12 PM
I tried un-checking the "Flash Prefetch" Option under the "System Settings".

This seems to have lowered my noise floor from the 20-30+mV range to 10 -<20mV. My "relative gain" has increased after running a while this way. So far, I haven't noticed a deterioration in response to the web interface or other performance issues.

The comment balloon says this about this function:
Quote
[The flash prefetch speeds up execution time, but creates some noise in the ADCs. Disable if you need higher ADC accuracy.]

Greg
Title: GHOST HUNTING
Post by: Cutty Sark Sailor on March 01, 2014, 11:57:01 AM
If you remember a few of my earlier posts,
you know that I was all over my residence last year finding the one "sweet spot" for antenna placement...

I'd also thought very little EMI was due to E field, inferring mostly H interference.
So this week I got ahold of a Trifield 100XE, more or less for the heck of it...
(If you know any Paranormal Ghosthunters, this is one model "they use to detect ghosts".
Maybe you can borrow one)

Notwithstanding any 'accuracy' or "professional" cross checks, using it only as a reference,
and during the particular times of day that I did 3 'Spook Checks',...
I detected zero E field anywhere near or in the area, unless the wife starts the older Nissan.
Or the Vacuum Cleaner (which drives the E meter nuts)...  :-)
Fired up the weedwacker for fun, and it spiked the Electrical also... .

But I've got H literally out the Ying-Yang, as I suspected.
60Hz, and harmonics, oddballs, heterodynes, Pulses, and Sines, etc..

Using numbers only as 'reference', not as 'accurate',
my antennas are sitting in the center of a 0.7 - 1.0 milligauss spot, about 4' square.
(http://www.ourspecialnet.com/Weather/TwinHollies/i-tJq7LgX/0/M/Relative%20H%20Field%20Reading-M.jpg) (http://www.ourspecialnet.com/Weather/TwinHollies/i-tJq7LgX/A)
and the Noise Level View at that time:
(http://www.ourspecialnet.com/Weather/TwinHollies/i-JLQXVdg/0/L/Noise%20at%20time%20of%20Image-L.jpg) (http://www.ourspecialnet.com/Weather/TwinHollies/i-JLQXVdg/A)
Any other areas exceed 1.0milligauss.

Stand there long enough with the meter near the antennas,
and watch the needle pulse when certain noise signals present. ...
Video of Meter Registering: http://www.ourspecialnet.com/Weather/TwinHollies/i-qggMRw4
 (http://www.ourspecialnet.com/Weather/TwinHollies/i-vFKrZnn/A)

..and the Noise Level View at the time of the video:

(http://www.ourspecialnet.com/Weather/TwinHollies/i-vFKrZnn/0/L/Signal%20at%20time%20of%20video-L.jpg) (http://www.ourspecialnet.com/Weather/TwinHollies/i-vFKrZnn/A)
No RF detected, and no E noticeable, at the times observed.

I did locate a previously 'unknown' spot that appears to consistently range 0.4 - 0.7 milligauss,
that may be convenient enough to locate to. Again, just utilizing the indication as "relative",...
relocating there should make a significant difference... at least on noise baseline.

Now,  though very quickly done, and preliminary, this was interesting,
because it confirmed what I'd determined and inferred using the 'AM' radio method,
and experimenting with various locations for the Antennas... .

Also explains why shielding my 300mm X 7.5mm ferrite antennas made little or no difference in overall baseline noise.
I do know that shielding decreased my ability to identify certain vehicles which drive by on a regular schedule.
Obviously I'll make more observations... if spring ever returns...

On the other hand, there could be ghosts on this hillside... hope they leave my newly discovered
second sweet spot unhaunted.... hmmm...What about a "Shielded, Tightly Wound, Ferrite Cored Exorcist"?
Who ya gonna call?  :roll:

Ain't this fun!
Mike

Title: Re: Interference and Noise
Post by: WXjem on March 01, 2014, 02:33:33 PM
Hi Mike,

Nice thread!  Thanks for starting it.

I found a way to reduce the amount of LOOP connection errors to my Davis Advantage VUE Console reported from my weewx software running on PC.  Replaced the included telco interface cable between the console and PC with a shielded serial cable.  This reduced the run length of the telco cable by just a few inches.  Just long enough to plug into console data logger pigtail and the supplied RJ4 to DB9 adapter. 

The weewx software handles these LOOP connection errors really well, but wanted to reduce them just the same.

Jim
Title: Re: Interference and Noise
Post by: dfroula on March 02, 2014, 10:58:25 AM
I thought I'd cross-post from blitzortung.org, since this fits the thread and may help some others.

I just discovered a significant source of noise pickup that I had overlooked. I installed a stereo jack on my amp to plug into an audio amp for monitoring the output of the Red amp for noise. I generally keep a 6 foot audio patch cable connected between the Red amp output test pins and a small audio headphone amp I built, for easy monitoring. I tried unplugging the cable from the Red amp at the jack, and my weird sine wave noise and DC blower motor interference vanished! It was being back-coupled through the audio cable to the OUTPUT of the Red amp. Duh. I should have thought of that!

The auto noise adjust feature is now much more stable and not kicking down the gains every time the furnace cycles. Easy fix...just connect the cable only when I want to monitor!

After I pulled that audio cable, set my manual threshold 1 notch above the manual sweet spot (now 16x8 on both channels, set the thresholds to the default 120 mv, re-enabled auto noise floor and my detection ratios shot right up.

However, there is still a small residual signal that seems to come on as the DC ECM furnace blower motor comes on with a call for heat from the thermostat. It is worse as the motor slowly ramps up to its normal operating speed from its low constant-on speed. At a steady speed, the interference is almost completely gone.

I keep the motor running continuously between heating calls for better air exchange, filtering, and more even temperatures in the house. It's one of the reasons I installed the motor last fall.

From what I can tell by the period of the interference, the frequency is in the 40 KHz region. Greg, your comment on the clamp-on ferrite RFI filter got me thinking. I did a search for any RFI information relating to ECM motors. I found the following in an RFI elimination bulletin from GE, the manufacturer of my motor (an "Evergreen" retrofit unit).

http://p1k.arrl.org/~mgruber/ECM_Motor_R...uction.pdf

 3) Thermostat Connections - Shielded or twisted
 connections for signal cables are desirable. Use
 bundled wires for thermostat cables and/or keep
 them separated as far as practical from TV, radio, or
 intercom cables.
 4) Filtering on Control Signals - Although this may not
 be needed, it has been shown that a small filter
 (capacitor or ferrite bead) connected from
 thermostat lines to ground will reduce EMI.
5) Cabinet Grounding Considerations The metal
 enclosure of a furnace or air handler should be an
 effective part of EMI filtering. Sometimes however,
 the metal panels do not make a reliable
 interconnection due to poor assembly, installation
 damage, or corrosion. This allows an increase in the
 radiated EMI of the system. Reduce this by
 grounding the cabinet and by keeping good electrical
 contact between all cabinet panels.

Since I had already made sure the motor ground was correctly bonded to the furnace cabinet and had a good ground from the cabinet to a cold water pipe, I started thinking that the thermostat cabling in the house might be coupling noise from the motor control leads (which connect directly to the thermostat wires on this motor) out of the cabinet and radiating from the run to the new Honeywell thermostat I recently installed.

I had one of the RFI snap-on ferrite filters I had used for ham-radio applications. I opened the furnace cabinet and wrapped the excess length of the thermostat cable bundle around the core three times. I found this completely eliminated the 40 KHz noise (likely the PWM switching frequency of the motor). I'm seeing far fewer noise threshold adjustment of the Red controller with auto-threshold turned on.

Don
Title: Re: Interference and Noise
Post by: dfroula on March 02, 2014, 01:01:38 PM
I very occasionally see this really high-frequency, low amplitude noise burst riding on a normal lightning signal. It's inconsequential as a noise source to the detector as the amplitude is so low, but I have often wondered what might be the source.

It reminds me of the colorburst signal that rides on an NTSC composite color video signal.

Don
Title: Re: Interference and Noise
Post by: dfroula on March 02, 2014, 04:53:41 PM
I found another EMI source...... :eek:
Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on March 02, 2014, 04:57:47 PM
I very occasionally see this really high-frequency, low amplitude noise burst riding on a normal lightning signal. It's inconsequential as a noise source to the detector as the amplitude is so low, but I have often wondered what might be the source.

It reminds me of the colorburst signal that rides on an NTSC composite color video signal.

Don
Yeah... one of them weirdo front porch references, however! Must be a Weather Channel signal... .
Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on March 02, 2014, 04:58:09 PM
I found another EMI source...... :eek:
You're gonna be RICH!
Title: Re: Interference and Noise
Post by: W3DRM on March 02, 2014, 05:19:53 PM
I very occasionally see this really high-frequency, low amplitude noise burst riding on a normal lightning signal. It's inconsequential as a noise source to the detector as the amplitude is so low, but I have often wondered what might be the source.

It reminds me of the colorburst signal that rides on an NTSC composite color video signal.

Don

I see a very similar trace every once in a while too. Although mine normally shows up just prior the main pulse. So far, I haven't been able to isolate it to anything local. Will try to capture a trace if I see it again.
Title: Re: Interference and Noise
Post by: dfroula on March 02, 2014, 05:54:48 PM
I wonder if it's an X-10 remote control signal? I have an alarm system that uses X-10 to trigger remote sirens, lights etc. I don't use any of them, but I recall I had the console set up to send turn-on signals for sirens and lights. I think X-10 runs on a carrier at 120 KHz.

Don
Title: Re: Interference and Noise
Post by: dfroula on March 03, 2014, 09:33:51 AM
Has anyone observed a noise source like this? While monitoring the noise on the Red controller scope, it manifests as a slow-moving "wave" that moves slowly across the screen from left to right. It only shows up when my ECM variable speed motor controller is running, and is predominant on channel 1 (red trace).

I think this may be harmonic distortion being introduced onto the AC line by the motor, which in turn radiates it through the power lines, where it is picked up by the antennas.

Sometimes the noise will cause an increase in the noise threshold which causes the auto-noise adjust feature to increase the threshold for a few seconds until it passes off the screen. Other times the threshold adjust algorithm ignores it and it manifests as an increase in false detections at a low rate until it passes.

I tried monitoring the AC line on my oscilloscope. I occasionally see a brief phase "shudder" (scope false-syncing on noise?) on the sine wave when the motor is running. The sine wave is very slightly  asymmetrical, but that is constant.

Don
Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on March 03, 2014, 10:44:47 AM
Has anyone observed a noise source like this? While monitoring the noise on the Red controller scope, it manifests as a slow-moving "wave" that moves slowly across the screen from left to right. It only shows up when my ECM variable speed motor controller is running, and is predominant on channel 1 (red trace).

I think this may be harmonic distortion being introduced onto the AC line by the motor, which in turn radiates it through the power lines, where it is picked up by the antennas.

Sometimes the noise will cause an increase in the noise threshold which causes the auto-noise adjust feature to increase the threshold for a few seconds until it passes off the screen. Other times the threshold adjust algorithm ignores it and it manifests as an increase in false detections at a low rate until it passes.

I tried monitoring the AC line on my oscilloscope. I occasionally see a brief phase "shudder" (scope false-syncing on noise?) on the sine wave when the motor is running. The sine wave is very slightly  asymmetrical, but that is constant.

Don
Don, you may have already explored the below link, but here:
http://www.eham.net/ehamforum/smf/index.php?ehamsid=ed5phohkb1vkr5s1hehvl79mf3&topic=86888.msg656389#msg656389

Mike
Title: Re: Interference and Noise
Post by: dfroula on March 03, 2014, 12:02:51 PM
Great info, thanks! It seems to discuss exactly the issue I'm seeing.

I did try wrapping the power leads in the furnace cabinet to the motor inside another snap-on ferrite RFI choke. The leads are quite thick (1 HP, 120 VAC motor), but I managed to get two loops of the hot and neutral leads through the core. It seems to have helped the common-mode noise some. It may not be that effective at the frequencies involved, as it is designed for higher RF frequencies. The same ferrite worked really well keeping ham VHF interference out of a high-current linear power supply.

I'm not sure if the issue is actually RF interference. I think the pulsed nature of the current draw of the ECM motor is creating harmonic distortion on the power line, distorting the AC waveform. This is a low-frequency phenomena. The classic fix is to throw a huge inductor in series with the hot lead(s) of the load to minimize the effects of the pulses of current drawn by the motor. Those things are really expensive. The issue isn't severe enough to justify that expense.

However, if the issue is RF interference, the Corcom 20-amp filter mentioned in your link (and in the GE app note I mentioned earlier) might be worth a try. They're a bit pricey ($30.00 - $60.00) used/new. I might try it, though. It's a cost/benefit thing.

Maybe GE has a free RF mitigation kit.

Thanks for that link!

Don
Title: Re: Interference and Noise
Post by: dfroula on March 15, 2014, 06:30:57 PM
In addition to getting a good ground installed on my system, I also cleaned up an intermittent noise issue I was having with a new ECM high-efficiency furnace blower I installed last fall. The new motor was causing harmonic distortion to be introduced back into the AC power on AC peaks because of the pulsed nature of the motor's current draw, compared to the smooth current draw of the old conventional PSC motor. Some of the harmonics were being radiated from the power wiring in the walls and fell within the passband of the receiver. They were being inductively coupled to the antenna, so the electrostatic shielding on the antennas wasn't helping.

GE, the manufacturer of the motor, was nice enough to send me a power factor correction choke that is wired in series with the hot power lead to the motor. The choke provided immediate reduction of the harmonic distortion noise under most operating conditions of the motor. I was seeing the noise force a temporary but significant reduction in gain when the heating system was running.

GE asked if I could produce a technical report in exchange for the free component, so I prepared one. It is located here, for those interested:

http://projectmf.homelinux.com/station_pics/Harmonic_Distortion_EMI.pdf

Regards,

Don
Title: Re: Interference and Noise
Post by: dfroula on March 17, 2014, 09:25:30 AM
I took some additional oscilloscope measurements that verified the effectiveness of the choke in attenuating the noise. Updated report at link:

http://projectmf.homelinux.com/station_pics/Harmonic_Distortion_EMI.pdf

Don
Title: Re: Interference and Noise
Post by: miraculon on March 17, 2014, 07:09:30 PM
Nice write-up. Excellent documentation. I saved it for future reference.

Greg
Title: Re: Interference and Noise
Post by: Dr Obbins on April 10, 2014, 08:57:46 PM
So...What do you think of this one? The dog's invisible fence.  :?
So how to minimize the effect?
Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on April 10, 2014, 10:35:12 PM
So...What do you think of this one? The dog's invisible fence.  :?
So how to minimize the effect?
If you've confirmed it's the fence, you have a hard job/decision in your backpack!  Especially since many of the frequencies and harmonics used are in the exact range we're trying to receive! (7-10K or similar). Arrrggghhh!  :sad:
Mike
Title: Re: Interference and Noise
Post by: W3DRM on April 10, 2014, 11:48:32 PM
So...What do you think of this one? The dog's invisible fence.  :?
So how to minimize the effect?

One of our neighbors has one of those invisible fences for their dog. They used it for several months but have now turned it off after their dog learned not to go past a certain line in the yard.

Have you tried turning it off and seeing if your dog stops before it gets to the fence line?
Title: Re: Interference and Noise
Post by: Dr Obbins on April 11, 2014, 05:23:35 AM
Yes it is still needed. We have 2 Chiwawa dogs - Beth and Jake. When their batteries on the collar need replacing, Beth notices with in a few days and likes running up and down the street. Even with the fence turned on, she will also get a running head start and jump as she crosses the boundary if there is something she really wants to get. She lets out a little yelp and then keeps on going. When Jake's collar broke, it took him about 3 weeks to notice and he started chasing rabbits. He would be so focused and dedicated to catching the rabbit that he wouldn't notice he was 5 yards away and didn't know where home was. So the fence does keep them in the yard 99% of the time.
Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on April 11, 2014, 10:03:32 AM
You might check and ensure that the perimeter wires aren't broken, somewhere, ... otherwise,
before the days of electric fences, we clipped a leash from the clothesline to our Chihuahua's harness... he could run and play within restrictions of line.
Applied the same principle to larger dogs over the years, except I ran 'dog run' ropes with pullies,  since we had ceased using metal clotheslines. Worked great, and dogs were content...
Mike
Title: Re: Interference and Noise
Post by: Dr Obbins on April 15, 2014, 04:22:38 AM
I woke up at 1:00am with one of those "Duh #-o" moments. The pet fence has a adjustment knob on it. I turned it down from 7 to 5 and while the noise is still there, it was greatly reduced. The collar will still work, just not quite as far from the buried wire as before. My wife was wondering why I was running up and down the steps from the basement to the 2nd floor in the middle of the night. LOL
Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on April 15, 2014, 06:14:04 AM
I woke up at 1:00am with one of those "Duh #-o" moments. The pet fence has a adjustment knob on it. I turned it down from 7 to 5 and while the noise is still there, it was greatly reduced. The collar will still work, just not quite as far from the buried wire as before. My wife was wondering why I was running up and down the steps from the basement to the 2nd floor in the middle of the night. LOL
  =D&gt;  My spouse has become used to all the "run and adjust" "run and observer"..RaA, RaO, RaA, RaO... between lightning and cameras, etc... . They seem to learn to accept it after awhile... especially running through the house and yard with am radios and EMI meters trying to find sources of EMI, and that exact camera adjustment etc,.. . Usually about all she'll say is "while you're out there, will you put feed in the bird feeders?"...
Title: Re: Interference and Noise
Post by: Dr Obbins on April 15, 2014, 08:46:25 PM
 Over the weekend, I was able to set the unit so it was in the 90+ efficiency long range. Then in the evening, it went into interference mode. With the house to my self tonight, I did a little researching into interference sources.

First with the pet fence turned down a pinch and nobody home all day, it was consistently reading in the 45% EL range. We have recessed lighting through the house and in the kitchen, there are 10 screw in florescent bulbs. With all 10 on, there was not any noticeable interference. Then the microwave was turned on and had a large impact. Also the light dimmers wreak havoc.

So the question is, is here a way to balance good reception and still live in the house? If the gain is turned down enough not to go into interference mode, the station stays in the 15% EL range. Is there another adjustment that should be considered?
Title: Re: Interference and Noise
Post by: Dr Obbins on April 16, 2014, 08:38:35 PM
Today I called the manufacturer of the light dimmers and explained the issue with the dimmers creating interference. To make a long conversation short - he said that I had to choose between using the dimmers or the lightning detector. At lunch I went out and purchased 3 non dimming light switches.  :grin:
Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on April 18, 2014, 06:10:56 AM
Lots of new Kits being built. Let me call this to your attention... it may happen:
When you connect the controller ground wire to the ground block, it is just possible that the torque from tightening the connector will snap the pin going through the circuit board... this nearly drove me nuts with intermittent high levels of noise.  ](*,) I then placed a tiny drop of hot glue on the base of the replacement  :roll:

So if you've got a noise issue, you might go back and check that...
I think the same thing could be possible with the antenna connection terminal block, though with 4 pins the twisting would be lessened.

Mike
Title: Re: Interference and Noise
Post by: DaleReid on April 19, 2014, 10:41:35 AM
How are you guys grabbing images of the signal level that you're showing?

I am running FireFox and when this signal tracing is displayed, when I right click and view or save the image, I get a grey block that has none of the info in it.

Is there another routine or app that I can get to ride on the top of firefox to grab those images?

Dale
Title: Re: Interference and Noise
Post by: Dr Obbins on April 19, 2014, 10:48:49 AM
I hit the "Print Screen" button real quick.
Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on April 19, 2014, 11:21:30 AM
I import screen capture into one of my versions of Paint Shop Pro, crop it there, etc.... The image you see on your web interface is a 'fake' image... server generated.
Title: Re: Interference and Noise
Post by: miraculon on April 19, 2014, 07:46:47 PM
I have been pleasantly surprised about the electrical environment here in Rogers City, MI. I took my RED lash-up down for permanent installation, and got the old "green"  ( USB 6.8 ) up and running. I have the "green" jumpers set to maximum gain without interference mode. RED was working well in the temporary setup in an upstairs bedroom, with higher gain than in my Livonia, MI home.

I have the threshold set to the default (same as the original fixed values) for now, but I was experimenting with much lower thresholds at the high gain.

I'll get RED back up and running in a few days. I am hoping for good results, since I used the "green" amplifier/antennas with a 9V battery and headphone to sniff out noises. I am installing both detectors in a detached garage, with a wireless client connecting to my Wireless Access Point.

Apparently my neighbors don't own a plasma TV..  \:D/

Greg
Title: Re: Interference and Noise
Post by: Dr Obbins on April 30, 2014, 03:42:48 AM
Any ideas what this might be. It is currently showing up at 2:30am with no activity in our house or either of the 2 neighbors. I live way out in the country. No street lights, no HVAC running, nothing at all going on around here.  :-$
It is not a brief event, but one that is showing up many times and stays on the screen for up to 30 seconds.
(http://www.cavecountryweather.com/Pictures/dontknow.jpg)
Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on April 30, 2014, 09:30:33 AM
Any ideas what this might be. It is currently showing up at 2:30am with no activity in our house or either of the 2 neighbors. I live way out in the country. No street lights, no HVAC running, nothing at all going on around here.  :-$
It is not a brief event, but one that is showing up many times and stays on the screen for up to 30 seconds.
With your a channel gain set so low it's hard to tell, but it's showing only on the b channel, so it's directivity is at right angles to that antenna which might help locate. When it's occurring, this link will show you your signals and frequency spectrum:
(link removed - shared privately)   (2.5 second sampling)
(easier for me to do, and probably less confusing for now... let me know when/if you want the page down....)

Mike

Title: Re: Interference and Noise
Post by: Dr Obbins on April 30, 2014, 09:34:25 PM
Interesting info. :-k This weekend I will have to go back to the attic and see which antenna is facing which direction and then analize the data being presented. The Direction Indication looks useful also. Please leave the page up for a bit.
Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on April 30, 2014, 09:55:50 PM
Interesting info. :-k This weekend I will have to go back to the attic and see which antenna is facing which direction and then analize the data being presented. The Direction Indication looks useful also. Please leave the page up for a bit.
Well, don't put a whole lot of 'faith' in being able to determine 'direction', because of the way the signals are received and processed, it's more of a 'fun' experimental thought, although it does have its uses and value at times, with a lot of practice.  :twisted:
Mike
Title: Re: Interference and Noise
Post by: miraculon on May 07, 2014, 10:25:54 PM
It looks like we need to replace the furnace in the house, so we have it shut down due to fumes and incomplete combustion. To take the chill off, I bought a "Vornado" heater with thermostatic control. I noticed in the "participants" list that #668 was offline. I checked the output web page and it is into interference mode. The Vornado is the cause of this, when I turn off the heater the station immediately comes out of interference mode. Turn it back on, interference mode. A-B-A test.

Strangely enough, the 6.8USB antennas (ferrite rod) are out in the garage and the heater is in the family room area at the rear of the house. I did have my threshold adjusted a little lower than normal, but the noise looks like it would exceed the default threshold as well.

It has a continuous motor control, so I expect that it is the culprit. I tried a clamp on ferrite to no avail. I'll attach the waveform shown in the screen-shot of the tracker.

UPDATE: This thing is going back to the store. It wipes out AM reception all over the house with a loud buzz. Again, I can make it come and go with the heater power switch.

Greg
Title: Re: Interference and Noise
Post by: miraculon on May 08, 2014, 10:21:58 AM
I took some additional oscilloscope measurements that verified the effectiveness of the choke in attenuating the noise. Updated report at link:

http://projectmf.homelinux.com/station_pics/Harmonic_Distortion_EMI.pdf

Don

I may be utilizing these fixes, since I am replacing my furnace. We'll see how it goes and if it is a big problem. That portable Vornado heater was obliterating the AM band and causing reduced gain on RED and on the "Green" it was in constant interference mode that could not be eliminated with the threshold control. If this is the "baby brother" of the furnace one, I am in for some headaches.... ](*,)

Greg
Title: Re: Interference and Noise
Post by: dfroula on May 08, 2014, 11:38:43 PM
The culprit is the variable speed DC blower and/or inducer motors in the furnace. The choke has continued to be very effective in attenuating the noise from the blower.

My inducer motor is a standard shaded-pole job, so doesn't contribute to the issue.

Don
WD9DMP
Title: Re: Interference and Noise
Post by: miraculon on May 09, 2014, 10:12:37 AM
Don,

Do you have the manufacturer, part number and inductance value of the PFC choke?
I found this York article that has filter kits. I will need to see how many fractional HP the motor is before I order one.
http://yorkcentraltechtalk.wordpress.com/2011/09/26/pf-choke-for-ecm-motors/ (http://yorkcentraltechtalk.wordpress.com/2011/09/26/pf-choke-for-ecm-motors/)
What do you think about getting one of these kits (appropriate to the motor size)?

Greg
Title: Re: Interference and Noise
Post by: miraculon on May 14, 2014, 06:49:04 PM
Good news. The new furnace isn't causing any interference mode problems. I can watch it before, during and after the furnace running and I don't see any change in the waveforms on both the "green" and RED detectors.

Greg
Title: Re: Interference and Noise
Post by: dfroula on May 14, 2014, 08:07:24 PM
Greg,

Good deal. Hopefully, they integrated the chokes into the motor!

The noise I was seeing in the controller signal display was subtle - just a small bump in the noise floor. It took an oscilloscope connected to the test outputs of the amp to spot the very narrow spike on positive and negative peaks of the AC waveform. It was so narrow, that sometimes the auto-noise floor reacted to it, sometimes not.

I just saw your request for info on my choke. Genteeq never gave me a precise value. The choke was made by Tyco, with a GE part number. The engineer said it was old stock from before Genteeq bought the motor division from GE. I can get the numbers if you like, but I plugged them into Google and found nothing.

Regards,

Don
WD9DMP
Title: Re: Interference and Noise
Post by: miraculon on May 14, 2014, 08:36:03 PM
Greg,

Good deal. Hopefully, they integrated the chokes into the motor!

The noise I was seeing in the controller signal display was subtle - just a small bump in the noise floor. It took an oscilloscope connected to the test outputs of the amp to spot the very narrow spike on positive and negative peaks of the AC waveform. It was so narrow, that sometimes the auto-noise floor reacted to it, sometimes not.

I just saw your request for info on my choke. Genteeq never gave me a precise value. The choke was made by Tyco, with a GE part number. The engineer said it was old stock from before Genteeq bought the motor division from GE. I can get the numbers if you like, but I plugged them into Google and found nothing.

Regards,

Don
WD9DMP

Thanks, Don. It looks like it is moot point since the motor is quiet. The "Vornado" experience had me nervous. Fortunately, they took that space heater back and I got an old-fashioned type. It looks like the Carrier/Payne (my new furnace) folks actually know how to spell "EMC"... :grin:

Greg
Title: Re: Interference and Noise
Post by: DaleReid on May 14, 2014, 09:24:48 PM
Speaking of noise clamps, are there sources for good clamp-around ferrites that one can snap over the power cords going from the USB supply to the controller, or around the various CAT 5 coming in, too?

I had some a few years ago that were rings and you had to wind stuff through them, then once while trying to reduce feedback in a radio intercom installation in a fiberglass homebuilt aircraft, we had some that were sort of slip and you just snapped the holder around the wire.  I'm not sure where those came from, or if it was even worth applying them to see if noise is cut down further.

Title: Re: Interference and Noise
Post by: miraculon on May 15, 2014, 08:14:42 AM
They certainly make them. I have used them, with mixed results. Sometimes they help, sometimes not.
Intermark USA has some low frequency versions. Most of the ferrites are effective in the 100's of MHz, which is not what we need for the Blitzortung system.

Here is the link to the Intermark LF ferrites. http://intermark-usa.com/products/emc/emi-ferrite-emi-ferrite-cores/low-frequency-khz-ferrite-cores/ (http://intermark-usa.com/products/emc/emi-ferrite-emi-ferrite-cores/low-frequency-khz-ferrite-cores/)

I think that TDK has some too. Mouser sells the TDK ZCAT series. http://www.mouser.com/Passive-Components/EMI-RFI-Components/EMI-RFI-Suppressors-Ferrites/Ferrite-Clamp-On-Cores/_/N-bw7t7/ (http://www.mouser.com/Passive-Components/EMI-RFI-Components/EMI-RFI-Suppressors-Ferrites/Ferrite-Clamp-On-Cores/_/N-bw7t7/)

Try eBay, there are some sellers there.

Greg
Title: Re: Interference and Noise
Post by: dfroula on May 15, 2014, 08:37:19 AM
I tried some Radio Shack snap-on ferrite chokes on the USB power leads, but noticed no effect. As Greg mentioned, they work well at VHF/UHF frequencies, but do little at the high-audio frequencies we are concerned with.

You might be able to find some ferrite torroids of appropriate material and wind the power cord through those. I would think you would want high-permeability (2000u) to be most effective - the same stuff the antenna ferrite rods are made of.

Regards,

Don
WD9DMP

Speaking of noise clamps, are there sources for good clamp-around ferrites that one can snap over the power cords going from the USB supply to the controller, or around the various CAT 5 coming in, too?

I had some a few years ago that were rings and you had to wind stuff through them, then once while trying to reduce feedback in a radio intercom installation in a fiberglass homebuilt aircraft, we had some that were sort of slip and you just snapped the holder around the wire.  I'm not sure where those came from, or if it was even worth applying them to see if noise is cut down further.
Title: Re: Interference and Noise
Post by: DaleReid on May 15, 2014, 01:14:55 PM
What if I take a ferrite rod and wrap the power line from the wall wart to the USB plug around it a few times, right near the board?  Exercise in futility or maybe worth a try?  Just thinking.  I have a lot of those rods...

Title: Re: Interference and Noise
Post by: dfroula on May 15, 2014, 03:06:39 PM
Worth a try. Toroids are nice because they are self-shielding, but the rods should work in this application. Put a few in a bundle....

Don
WD9DMP
Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on May 30, 2014, 09:36:58 AM
 =D&gt;
Many of you who've ordered E field kits, and have had issues with interference on the H field location are going to be pleasantly surprised.
I had determined my environment was heavily H field noise, with little or no E field issues, but was still a bit concerned, being who and what I am.
Some of my EMI is 'seasonal', so the jury is still out on what the environment will be like come cold weather, but the E Probe picks up little or none of the signals from nearby Axle plant that causes issues with my N/S H field. Also no plasma TV, believe it or not, from next door, and little or nothing from the same vapor lights that periodically mess with H field.
What E field does have is high gain. Experiments show it exceeds the H-field in many respects, so Interference mode comes simply from too dang many signals exceeding threshold.

With 5 channels running, instead of 2, it can be tricky to see where any interference is coming from. However, I've learned it's almost never related to the E field probe, and almost always due to my A amp Ch1, (the N/S aimed at the axle factory ferrite  :-)  )

The point is, I think, that if you've had issues with H field reception, you may do a lot better adding E field.

Cheers!
Title: Re: Interference and Noise
Post by: W3DRM on May 30, 2014, 11:21:54 AM
=D&gt;
Many of you who've ordered E field kits, and have had issues with interference on the H field location are going to be pleasantly surprised.
I had determined my environment was heavily H field noise, with little or no E field issues, but was still a bit concerned, being who and what I am.
Some of my EMI is 'seasonal', so the jury is still out on what the environment will be like come cold weather, but the E Probe picks up little or none of the signals from nearby Axle plant that causes issues with my N/S H field. Also no plasma TV, believe it or not, from next door, and little or nothing from the same vapor lights that periodically mess with H field.
What E field does have is high gain. Experiments show it exceeds the H-field in many respects, so Interference mode comes simply from too dang many signals exceeding threshold.

With 5 channels running, instead of 2, it can be tricky to see where any interference is coming from. However, I've learned it's almost never related to the E field probe, and almost always due to my A amp Ch1, (the N/S aimed at the axle factory ferrite  :-)  )

The point is, I think, that if you've had issues with H field reception, you may do a lot better adding E field.

Cheers!

Mike - just thinking out loud here - what happens with your H-field noise levels if you rotate your antenna by 45 one way or the other? Do they increase or decrease? Of course, it may then get picked-up on both antennas...
Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on May 30, 2014, 12:19:43 PM
Mike - just thinking out loud here - what happens with your H-field noise levels if you rotate your antenna by 45 one way or the other? Do they increase or decrease? Of course, it may then get picked-up on both antennas...
Correct. The axle factory moves to both channels... Now, the Plasma used to mess with E/W antenna till I conned my neighbor into moving it into another corner, so it'd mostly hit N/S.  Stay on the utility company's butt about the outdoor lighting on them dang poles. Neighbor across the street has a riding mower with bad ignition wires, kinda fun to watch him move from west to east on the H field, but, believe it or not, the E field seems to ignore it.
Believe me also... there's only one sweet spot for lowest H field within 50 ft of where I'm sitting. Took a couple of months to find it, but I did. It is nice that I'm able to orient the ferrites E/W and N/S for other reasons.

Eventually I'll get my ferrites off the cardboard and into a weathermount... I think I've found another sweet spot 6 ft off the ground inside one of the Holly trees from whence the website draws its name.  :twisted:

Funny, we chased EMI for months, the first few of us.... don't hear a lot from you newbies... maybe our pain helped y'all.
Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on May 30, 2014, 12:21:38 PM
Oh, btw... rotating the antennas horizontally  is one way to begin isolating direction of EMI.. 'course you don't have that asset with the E field Probe...
Title: Re: Interference and Noise
Post by: W3DRM on May 30, 2014, 04:26:10 PM
Oh, btw... rotating the antennas horizontally  is one way to begin isolating direction of EMI.. 'course you don't have that asset with the E field Probe...

Well, you might be able to get some idea simply by laying the vertical antenna flat and rotating it and looking for a good null or dip in the received levels. I've done that with mobile verticals to find noise sources. It mostly depends on how far away the noise source is from the antenna. Too close, and it may saturate the input and not give you any kind of a null. Can't hurt to try though. It will be just one more piece of the learning curve.
Title: Re: Interference and Noise
Post by: fpalafox on June 14, 2014, 10:25:08 PM
Thank you guys for your post! I am new in blitzortung station. My red station was working with some interference, but today is interfered for las 24 hours. I was moving my e-field antenna but no changes, then i removed the coaxial cable from the amp input and my surprise is the signal still inside. Then i moved the amp gain to minimal 1x1x16 and signal still present. Looks like is autogenerated by amplifier. Please check my atach and comments are very welcome. Thank you .
Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on June 15, 2014, 07:10:58 AM
You signals look good this morning... http://ourspecial.net/twinhollies/weathercenter/blitz/fp1023/index.html
we can explore as the interference returns...

If you'd move your E field amplifier to the #2 controller connection, instead of #1, we'd all be looking at the same color signals. Red and green and yellow have us thinking an H field signal...
the amp2 input produces magenta, blue and orange signals. We're all trying to stay with the same display when we look at each other's signals to assist someone... We run H field on amplifier one, and e field on amp 2... follow me?  ;)

Mike
Title: Re: Interference and Noise
Post by: fpalafox on June 15, 2014, 02:35:26 PM
Thank you Mike! I moved ampl to input 2. You right, interference is not there!!! Yesterday after my post here i take out my ampl card and clean every parts, i hope this fix the issue!
Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on June 15, 2014, 04:53:26 PM
Thank you Mike! I moved ampl to input 2. You right, interference is not there!!! Yesterday after my post here i take out my ampl card and clean every parts, i hope this fix the issue!
Yes, interference can occur at times, and at different seasons. Keep an eye on it, and see if or when it returns... I think you mentioned that you had it earlier, at night.  Now, many of us have gained experience at tracking down H field noise, so we'll all learn together about E field... it's somewhat different.  Since you may have some 'intermittent' noise source, you'll be a 'pioneer' in this area, and probably a big help to others!
Title: Re: Interference and Noise
Post by: ayde_bury on June 16, 2014, 04:34:56 PM
Any thoughts on this signal. It repeats pretty much most of the time on Amp 1 Channel A (the red line) It dips above and below the main 0v centre line and occasionally has a sharp drop either up or down :(

(http://www.lightningmaps.org/blitzortung/europe/index.php?bo_graph&bo_station_id=975&bo_time=2014-06-16+19%3A57%3A45.635869276&lang=en&bo_size=3)

I also have the message

Amplifier 1 - PCB 12.3 - FW 1.7
CommunicationRx: 2m, 24s ago / Tx: 2m, 24s ago
Channel A TriggerConflict with shared channel (wanted 1798mV). Desired gain can not be reached!
Gains1 * 1 * 40 = Total Gain 40
Noise1397mVpp

The signal is so smooth, could this be a problem with the newly built AMP?
Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on June 16, 2014, 04:42:43 PM
Yeah, Enable "advanced Channel Mapping" ??? ... see our start-up thread. the initial post... http://www.wxforum.net/index.php?topic=22710.0
Won't do anything about the interference, perhaps, but get started good, with E on amp 2, advanced channel mapping enabled so the antennas operate on the same amplifiers, and we can go from there....

Mike...
Title: Re: Interference and Noise
Post by: ayde_bury on June 16, 2014, 04:54:57 PM
I have alternate channel mapping enabled as per that post, is it the same thing or am I missing something else?
Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on June 16, 2014, 05:01:09 PM
I have alternate channel mapping enabled as per that post, is it the same thing or am I missing something else?
Yes...  Ok... needed to make sure,... you can turn off "force all channels on" for now, if it's on.

I've not seen this issue.. are you just running  E field for now? and It's on amp 2? 
I Had a similar problem with channel A as far as the signal goes, a cold solder joint in the amp on one of the A amp IC's... it's the gain/ threshold error that's throwing me right now. The only power supply connected is to the controller, right?

If you've got your preamp and probe inside, near computers, etc it could explain part of the interference...
What's your red station number?
Title: Re: Interference and Noise
Post by: ayde_bury on June 16, 2014, 05:08:07 PM
E-Field is on Amp two, and running fine.

The signal is appearing on the H-field, Amp 1. I've rotated the antennas through 90 degrees to see if it's picked up by the other antenna, but no change.

The unit is powered by a 5v supply only on the controller board and both amps are connected by STP cables.

All computer equipment is at minimum of 20m from the Red equipment.

I'm station no 1039 - United Kingdom, Barrow, Bury St Edmunds Suffolk (must update my forum sign :))

Thanks in advance for any suggestions or help.
Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on June 16, 2014, 05:34:06 PM
E-Field is on Amp two, and running fine.

The signal is appearing on the H-field, Amp 1. I've rotated the antennas through 90 degrees to see if it's picked up by the other antenna, but no change.

The unit is powered by a 5v supply only on the controller board and both amps are connected by STP cables.

All computer equipment is at minimum of 20m from the Red equipment.

I'm station no 1039 - United Kingdom, Barrow, Bury St Edmunds Suffolk (must update my forum sign :))

Thanks in advance for any suggestions or help.
I'll check more later... I'd first take my A amp board, touch a hot soldering iron to every SMD pin on the board that handles channel A... that may very well fix it.
Title: Re: Interference and Noise
Post by: meteo-melin on June 17, 2014, 05:35:27 AM
Hello,

Can someone help me with a huge noise problem?
The station recieves a lot of signals since I moved it in the capital :D

Here is a video of the signals it gets: http://www.meteomelin.be/files/signals.mp4

Note that the amp/antenna are not the problem because it worked very well in another place.

So, does someone have an idea from where those signals could come from? 

Station 680 Region 1 :D

Thanks :)
Clment
Title: Re: Interference and Noise
Post by: dfroula on June 17, 2014, 09:28:00 AM
This looks like the noise I was seeing when I added shielding to the ferrite antennas, but had not grounded the system through the controller.

I have seen similar noise when shielding was used on the ferrites, but the signal/ground connection(s) at the amp board were reversed so that the shield(s) was connected to the non-grounded input of the amp.

Best,

Don
WD9DMP
Title: Re: Interference and Noise
Post by: ayde_bury on June 18, 2014, 05:55:16 AM
Further to the weird Red signal on channel A above, I've completed the following:

Recheck all solder joints on components of input A.
Reheat and ensure SMC chips are seated correctly - or as correct as I can see through a magnifying glass with fine iron.
Rotate the board 90 degrees to see if the signal is external and picked up by input B (it isnt).
Swap the input A and input B ferrite antenna to see if there is a ferrite problem (problem stays on the amp).
Swap input 1 and input 2 on the controller board, the fault follows the Amplifier.
Changed the USB PSU in case its a problem.
Removed the ferrite antennas.

All these still point to the problem somewhere on the AMP. I have also popped an email across to Egon to see if he can shed any light on it. Forgot to order the GPS antenna, so that should be with me before the end of the week - far too much excitement.

Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on June 25, 2014, 11:13:21 AM
Here's what appears to be a 32KHz source... from a new station startup:
It's generating 64KHz, 96Khz and 128KHz harmonics and 48, 60, 92 subs or beats.
(http://ourspecial.net/twinhollies/weathercenter/blitz/1042Mesa/1042%20mesa%20B%20noise.jpg)
More info as it resolves :grin:
Question: what is the most common use of 32Khz?  :twisted: Got it???
Mike  06/25/2014
Title: Re: Interference and Noise
Post by: ayde_bury on June 25, 2014, 02:55:52 PM
Just as a quick update, an electronics engineer took a look at my amplifier and it looks like he has found my funny wave form cause.

Somehow I had confused a 6.8k and 68k resistor when checking them with a meter prior to installing them on both channels - the other channel was acting fine as it has a dry joint on one of the ICs  :oops:
Title: Re: Interference and Noise
Post by: Knickohr on June 26, 2014, 03:29:51 AM
"Question: what is the most common use of 32Khz?  :twisted: Got it???"

Crystals for chronometers !

Thomas
Title: Re: Interference and Noise
Post by: dfroula on June 26, 2014, 07:39:42 AM
You mean the incorrect part was installed on both channels, but a high-resistance solder connection on one was allowing it to work?

That's not fair when two issues cancel each other out!  :-)

Glad you got it sorted!

Best regards,

Don
WD9DMP

Just as a quick update, an electronics engineer took a look at my amplifier and it looks like he has found my funny wave form cause.

Somehow I had confused a 6.8k and 68k resistor when checking them with a meter prior to installing them on both channels - the other channel was acting fine as it has a dry joint on one of the ICs  :oops:
Title: Re: Interference and Noise
Post by: ayde_bury on June 26, 2014, 04:16:00 PM
Thanks for everyones support here - and that of the said engineer if he reads this forum :)

I should be up and running again very soon - yeah!!
Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on June 26, 2014, 04:20:47 PM
"Question: what is the most common use of 32Khz?  :twisted: Got it???"

Crystals for chronometers !

Thomas
So, if I've got 32kHz,  and multiple, signals.... ?
Title: Re: Interference and Noise
Post by: Silversword on June 27, 2014, 02:17:39 AM
Hi All,

Got some crazy looking frequency graphs tonight.  Don't know how to interrupt this.

This weekend I will take my system down and check out the amplifier board and see if there is a soldering issue.  Also will try to shield the ferrite antenna. Up until now it has been unshielded.  Also will relocate the controller board to a slightly different location, just a couple of feet away from my weather computer that is running 24/7.  Up until now it is just about a foot away from this computer. When I move it it will be about 4 feet away from this computer and hope it will make some difference.

Currently the amplifier and antenna is about 25 feet away from the amplifier board.  Cannot get it any further away than this for now.

Any suggestions or ideas that I could improve my interference issue will be very much welcome.

Regards,

--Stan Y.
   Maui, Hawaii


 
Title: Re: Interference and Noise
Post by: JonathanW on June 27, 2014, 07:36:02 AM
"Question: what is the most common use of 32Khz?  :twisted: Got it???"

Crystals for chronometers !

Thomas
So, if I've got 32kHz,  and multiple, signals.... ?

...you live in a clock factory? ;)
Title: Re: Interference and Noise
Post by: Knickohr on June 27, 2014, 07:53:43 AM
 \:D/

Thomas
Title: Re: Interference and Noise
Post by: dfroula on June 27, 2014, 08:41:09 AM
It looks like low-frequency sinusoidal interference with the lightning signals riding on top of it.

Did you get those antennas out from under the metal roof? That could cause some odd issues.

Don
WD9DMP

Hi All,

Got some crazy looking frequency graphs tonight.  Don't know how to interrupt this.

This weekend I will take my system down and check out the amplifier board and see if there is a soldering issue.  Also will try to shield the ferrite antenna. Up until now it has been unshielded.  Also will relocate the controller board to a slightly different location, just a couple of feet away from my weather computer that is running 24/7.  Up until now it is just about a foot away from this computer. When I move it it will be about 4 feet away from this computer and hope it will make some difference.

Currently the amplifier and antenna is about 25 feet away from the amplifier board.  Cannot get it any further away than this for now.

Any suggestions or ideas that I could improve my interference issue will be very much welcome.

Regards,

--Stan Y.
   Maui, Hawaii
Title: Re: Interference and Noise
Post by: Silversword on June 27, 2014, 01:04:59 PM
Hi Don,

It is still under the aluminum roof in the attic.  Just to see what happens.  When I take it down this weekend for some work on the amplifier and shielding the ferrite antenna and perhaps making an enclosure for an outside box for the amplifier and antenna and see what happens in a couple of days of down time to get it up and running.

Will keep on trying..

Thanks for your input..

Maybe Mike will be able to see what is going on too.

Regards,

--Stan Y.
  KH6HHG
  Maui, Hawaii
Title: Re: Interference and Noise
Post by: meteo-melin on July 03, 2014, 01:55:37 PM
Hello,

Can someone help me debugging station 898 (region 1) signals?

It does not go in interference but has a lot of signals compared to the number of strikes.

Thanks
Title: Re: Interference and Noise
Post by: dfroula on July 03, 2014, 05:52:32 PM
There is a very strong noise signal at about 20KHz on both of your channels. I suspect you have the gains set very low to avoid the noise sending your station into interference mode, as the signal rate and strike rates are quite low.

The attached signal does show a good strike detection, so your amps are likely working fine. Because of the low gains, only very strong lightning signals will be detected and sent to the server.

You need to identify and correct that 20KHz noise source!

Best regards,

Don
WD9DMP

Hello,

Can someone help me debugging station 898 (region 1) signals?

It does not go in interference but has a lot of signals compared to the number of strikes.

Thanks
Title: Re: Interference and Noise
Post by: meteo-melin on July 04, 2014, 04:11:13 AM
Hello,

Thank you for the tip.
Indeed, the gains are very low.
What kind of disturber can produce a 20 kHz noise? Can it come from the station itself?

Thank you.

Regards,
Clement
Title: Re: Interference and Noise
Post by: JonathanW on July 04, 2014, 09:48:51 AM
What kind of a power supply are you using?  Does the noise ever go away, and did it have a defined start/stop time?
Title: Re: Interference and Noise
Post by: meteo-melin on July 04, 2014, 11:25:46 AM
The noise is always present.

I use the power supply which was included in the full kit ordered to Egon: http://www.reichelt.de/USB-PA-230V-5V1A/3/index.html?&ACTION=3&LA=446&ARTICLE=97412&artnr=USB+PA+230V+5V1A&SEARCH=USB+PA+230V+5V1A

Thanks.
Title: Re: Interference and Noise
Post by: dfroula on July 04, 2014, 11:55:53 AM
Compact fluorescent bulbs, laptop or other PC too close to antennas, electric dog fence, robot lawn mower are all possible culprits.

Try powering off your laptops/PCs one at a time and see if the interference stops.

Turn off one AC circuit at a time from your circuit breaker/fuse box. Note which circuit powers the offending device. If you are fortunate, the offending device will be within your home. If it is on a neighbor's property, the solution will be more difficult.

Do you have a single-point ground on the Controller board? This is especially important if you are using ferrite antennas with shields.

The amplifier may be too close to the controller. Try moving the amp/antennas so that the units are separated by at least 5 meters.

Set your LCD backlight options to run at 100% brightness with a 30-second timeout to 0%. See if the noise diminishes at 100% brightness or when the backlight is off.

You must use shielded cat 5 cabling to connect the amplifier to the controller to avoid noise pickup.

If you re-orient your antennas, does the noise shift from one channel to the other? If it does, the noise source is likely external to your system power supply/cabling.

Don
WD9DMP
Title: Re: Interference and Noise
Post by: W3DRM on July 04, 2014, 12:24:48 PM
Compact fluorescent bulbs, laptop or other PC too close to antennas, electric dog fence, robot lawn mower are all possible culprits.

Try powering off your laptops/PCs one at a time and see if the interference stops.
[...snip...]

I found that one of my very old Dell laptops, even though it was turned-off, was radiating high levels of noise. It went away when I unplugged the ac-adapter from the AC outlet. So, just turning a device off may not eliminate the noise source.
Title: Re: Interference and Noise
Post by: Dr Obbins on July 04, 2014, 12:44:58 PM
I found it easier to wait until every one else had left the house and turn everything off - even circuit breakers. This way I could tell if the noise was from inside my control or outside the house. Then went room by room turning items on and seeing if there was a change in the noise floor.
Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on July 04, 2014, 12:54:50 PM
I found it easier to wait until every one else had left the house and turn everything off - even circuit breakers. This way I could tell if the noise was from inside my control or outside the house. Then went room by room turning items on and seeing if there was a change in the noise floor.
Aren't you the one that removed all the light dimmers and replaced 'em with switches while the wife was grocery shopping... :twisted:

Seriously... I just gave my son a brand new ACER high end computer that he took to Colorado.... it no longer swamps my system with its stupid high level emissions. But look out Grand Junction... he's on the front range, and if you start having issues, PM me and I'll tell Him to go dump it in the Poudre River....
Title: Re: Interference and Noise
Post by: JonathanW on July 04, 2014, 01:25:22 PM
I found it easier to wait until every one else had left the house and turn everything off - even circuit breakers. This way I could tell if the noise was from inside my control or outside the house. Then went room by room turning items on and seeing if there was a change in the noise floor.
Aren't you the one that removed all the light dimmers and replaced 'em with switches while the wife was grocery shopping... :twisted:

That's my plan, as well.  Please keep it quiet :)
Title: Re: Interference and Noise
Post by: meteo-melin on July 04, 2014, 02:00:53 PM
Ok... I'll try that...

Btw, is a metallic desk a good ground?
Title: Re: Interference and Noise
Post by: Dr Obbins on July 04, 2014, 02:03:27 PM
I found it easier to wait until every one else had left the house and turn everything off - even circuit breakers. This way I could tell if the noise was from inside my control or outside the house. Then went room by room turning items on and seeing if there was a change in the noise floor.
Aren't you the one that removed all the light dimmers and replaced 'em with switches while the wife was grocery shopping... :twisted:
uh.....yea..... :-"
Title: Re: Interference and Noise
Post by: dfroula on July 05, 2014, 11:26:30 AM
That is NOT a good ground, and will possibly make your interference worse by acting as an antenna for the noise.

"Ground" in this context means a wire run to a metal rod that is driven into the ground at least 1 meter or so in conductive soil.

An alternative might be to connect to the home power wiring protective ground at a power outlet wall plate. I'm not familiar with how residences are wired in Belgium, but there should be protective ground at the power outlet that does not normally carry current. Niko-style plugs have such a ground (http://www.niko.eu/nlbe/niko/artikel/100-66601). That protective ground must be wired to a suitable ground rod at your power distribution panel.

Don
WD9DMP

Ok... I'll try that...

Btw, is a metallic desk a good ground?
Title: Re: Interference and Noise
Post by: Knickohr on July 06, 2014, 06:01:55 AM
Today, it's very quite, not much lightning, only a few strokes around Germany.

So I try to find out some other unwanted "noise-generators" and found one :

The controller itself  :twisted: The LCD, specially the voltage generation for the display-contrast :

(http://www.sternhimmel-ueber-ulm.de/blitz/LCD1.gif)

The little sharp green spikes are produced from the negative voltage generation for the LCD. In this case, the developer should redesign this simple circuit.

Workaround :

Disable the PWM for the backlight by setting "Brightness" to 0 or 100%, setting "Auto Off" to a few seconds. This will disable the voltage generation for the contrast after the given time and also disables communication to the LCD.

(http://www.sternhimmel-ueber-ulm.de/blitz/LCD3.gif)

Result :

After the given time, no noise anymore from the display :

(http://www.sternhimmel-ueber-ulm.de/blitz/LCD2.gif)

This in not new, but it's a small thing to do, to avoid additional noise.

Thomas
Title: Re: Interference and Noise
Post by: JonathanW on July 06, 2014, 08:31:35 AM
Thomas,
You are correct; the LCD is a known noise source.  I set the level to 100% and disabled after 3 seconds on mine.  See:

http://www.wxforum.net/index.php?topic=20439.msg201216#msg201216 (http://www.wxforum.net/index.php?topic=20439.msg201216#msg201216)
Title: Re: Interference and Noise
Post by: miraculon on July 06, 2014, 01:23:00 PM
In addition to defeating the PWM on the controller, I found a small advantage to disabling "flash prefetch". I posted this earlier.

http://www.wxforum.net/index.php?topic=20439.msg208992#msg208992 (http://www.wxforum.net/index.php?topic=20439.msg208992#msg208992)

Quote
I tried un-checking the "Flash Prefetch" Option under the "System Settings".

This seems to have lowered my noise floor from the 20-30+mV range to 10 -<20mV. My "relative gain" has increased after running a while this way. So far, I haven't noticed a deterioration in response to the web interface or other performance issues.

The comment balloon says this about this function:
Quote

    [The flash prefetch speeds up execution time, but creates some noise in the ADCs. Disable if you need higher ADC accuracy.]

Greg H.
Title: Re: Interference and Noise
Post by: fpalafox on July 09, 2014, 02:41:36 PM
Hi Guys,
I have a interference mode for the last 5 days, but looks like is a self generated signal inside the E-Field amp. I am including file. Could you give me a hand? I review all components according to electric diagram, I re-soldering all components yesterday from Amp but still signal present.

Signal is inside if I disconect pre-amp cable, or if I set to 1x1 gain, Including if I move the amp to an other place.
Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on July 09, 2014, 04:10:30 PM
Franciso, what is your power supply doing?  look at your signals page, and switch on the "enable 5 volt sampling".... should be nice and smooth, maybe 50mv noise grass...

This does look like an external signal getting in, however.... are you using shielded cat cable?

Mike
Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on July 09, 2014, 04:19:00 PM
Hi Guys,
I have a interference mode for the last 5 days, but looks like is a self generated signal inside the E-Field amp. I am including file. Could you give me a hand? I review all components according to electric diagram, I re-soldering all components yesterday from Amp but still signal present.

Signal is inside if I disconect pre-amp cable, or if I set to 1x1 gain, Including if I move the amp to an other place.
Franciso, what is your power supply doing?  look at your signals page, and switch on the "enable 5 volt sampling".... should be nice and smooth, maybe 50mv noise grass...

This does look like an external signal getting in, however.... are you using shielded cat cable?

Mike
Franscisco's signals are at http://frankfortweather.us/BoStaSig/


There is a higher freq signal up around 300Khz coming from somewhere, and it must be really strong. If he's getting killed with a subharmonic, somethings coming in wild about 6Hhz
Title: Re: Interference and Noise
Post by: fpalafox on July 09, 2014, 07:28:06 PM
Thank you for your reply. I am using a 5V Samsung power supply (2A), I switch to an other and not changes, then connect the USB to standart PC USB conection and still same . 5v screen included.

From AMP to Main Board I am using a shielded 1 foot cable.
Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on July 13, 2014, 07:57:28 AM
7/13/2014: Added the following to the primary post:
" Among other difference between E and H fields amps: You CANNOT DISABLE E-field signals by checking "don't send" on the settings page. The server wants to see all three channels. Best you can do is set gains to 1x1, thresholds to "0". You can adjust gains. E field signals look different, and interference location is a different process.

Added 7/11/2014 ... Server signal display for active stations: http://frankfortweather.us/BoStaSig/  Shows you what the server is seeing from your station. Additionally signal spectrum is displayed to help find 'interference' frequency peaks."
Title: Re: Interference and Noise
Post by: W3DRM on July 14, 2014, 11:22:56 PM
Looks like my 2B amp has gone south. I get a constant waveform on the channel regardless of the settings. I have dropped all inputs (Amp 1 and Amp 2) to 1.1 but the the waveform on channel 2B stays the same. Resetting everything has no effect either.

Sadly, I'm too busy with family here for the next week or so and won't have any time to work on it. I suspect something has happened with the E-field amp. It does sit in an outside enclosure and we have had temps over 100F for the past couple of days. I need to place a temp sensor inside the enclosure to see just how hot (or cold) it does get in there.

You can see the crazy waveform on Cutty's signal info page (select the Minden station):
Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on July 15, 2014, 01:05:55 AM
chk solder connections on B smds...
Title: Re: Interference and Noise
Post by: W3DRM on July 15, 2014, 12:07:58 PM
Looks like my 2B amp has gone south. I get a constant waveform on the channel regardless of the settings. I have dropped all inputs (Amp 1 and Amp 2) to 1.1 but the the waveform on channel 2B stays the same. Resetting everything has no effect either.

Sadly, I'm too busy with family here for the next week or so and won't have any time to work on it. I suspect something has happened with the E-field amp. It does sit in an outside enclosure and we have had temps over 100F for the past couple of days. I need to place a temp sensor inside the enclosure to see just how hot (or cold) it does get in there.

You can see the crazy waveform on Cutty's signal info page (select the Minden station):
  • http://frankfortweather.us/BoStaSig/ (http://frankfortweather.us/BoStaSig/)

FIXED! I was wrong about the E-amp being outside. It is inside next to my RED controller board and connected to the E-preamp via a coax. We have family here and they are using the office as their bedroom. Seems as though someone plugged-in their iPhone charger into my power distribution box and then laid the cable across the top of the E-field amp. It picked-up the radiated signals from the wal-wart. I simply moved the power cable away from the E-field amp and the problem was solved!
Title: Re: Interference and Noise
Post by: JonathanW on July 15, 2014, 12:14:44 PM
Looks like my 2B amp has gone south. I get a constant waveform on the channel regardless of the settings. I have dropped all inputs (Amp 1 and Amp 2) to 1.1 but the the waveform on channel 2B stays the same. Resetting everything has no effect either.

Sadly, I'm too busy with family here for the next week or so and won't have any time to work on it. I suspect something has happened with the E-field amp. It does sit in an outside enclosure and we have had temps over 100F for the past couple of days. I need to place a temp sensor inside the enclosure to see just how hot (or cold) it does get in there.

You can see the crazy waveform on Cutty's signal info page (select the Minden station):
  • http://frankfortweather.us/BoStaSig/ (http://frankfortweather.us/BoStaSig/)

FIXED! I was wrong about the E-amp being outside. It is inside next to my RED controller board and connected to the E-preamp via a coax. We have family here and they are using the office as their bedroom. Seems as though someone plugged-in their iPhone charger into my power distribution box and then laid the cable across the top of the E-field amp. It picked-up the radiated signals from the wal-wart. I simply moved the power cable away from the E-field amp and the problem was solved!

Should probably mention that as something "not to do" in the project documentation  :grin:

"No family with wall wart power supplies near the system"
Title: Re: Interference and Noise
Post by: dfroula on July 15, 2014, 12:23:21 PM
Just a note, I have found that faulty bridge diodes on non-switching mode, unregulated wall-warts can kick up a lot of line noise. An AM radio works great to trace those down, if you should have the misfortune of having one plugged in in your home.

Glad it was an easy fix!

Don
WD9DMP

Looks like my 2B amp has gone south. I get a constant waveform on the channel regardless of the settings. I have dropped all inputs (Amp 1 and Amp 2) to 1.1 but the the waveform on channel 2B stays the same. Resetting everything has no effect either.

Sadly, I'm too busy with family here for the next week or so and won't have any time to work on it. I suspect something has happened with the E-field amp. It does sit in an outside enclosure and we have had temps over 100F for the past couple of days. I need to place a temp sensor inside the enclosure to see just how hot (or cold) it does get in there.

You can see the crazy waveform on Cutty's signal info page (select the Minden station):
  • http://frankfortweather.us/BoStaSig/ (http://frankfortweather.us/BoStaSig/)

FIXED! I was wrong about the E-amp being outside. It is inside next to my RED controller board and connected to the E-preamp via a coax. We have family here and they are using the office as their bedroom. Seems as though someone plugged-in their iPhone charger into my power distribution box and then laid the cable across the top of the E-field amp. It picked-up the radiated signals from the wal-wart. I simply moved the power cable away from the E-field amp and the problem was solved!
Title: Re: Interference and Noise
Post by: weatherc on July 15, 2014, 06:08:45 PM
Hi guys,

A partly repost of my post on BO-forum...

I use the station off-grid with solarpower. Theese solarstuffs generates "some" noises whats not figured out yet if they can be "cleaned out". I guess not.

- Doing settings the "normal way" to get it "quiet" ended up with like 4x2 gains H-field what resulted in ca 20 strikes/hour (what was less than 1%).
- Automode do not even get it out from inteference
- Auto noise just jumps up and down like a jo-jo in continous inteference
- The trick: Find the gains where Alptitude-filter gets those solar-noises filtered. In my case are it 10x5 gains on H-field and 8x4 for E-field. This gives a continous ca "raw" 200 signals/s. But as sent data went it in a 15-22% signals-to-strikes-ratio and as best today ca 850 strikes/hour and ca 70% of the 50-500 km range  ;)
Even one step up or down in gains screws the filtering and plentty of signals are sent.

It do not detect that many stirkes really far away this way, farthest has been 2400 km away tought but main part of the detected strikes has been < 1500 km away but that was expected.
Another was how it acts now at the evening when acticity drops. And yes, the amount of sent signals has dropped too, at the moment is it ca 500 signals/s what ends in 5% signal-stirke-ratio.

// Henkka
Title: Re: Interference and Noise
Post by: JonathanW on July 20, 2014, 02:39:44 PM
So, new, low-level interference (H-field) at my location, started two days ago in the evening.  It's a roughly 52 kHz signal.

(http://www.lightningmaps.org/blitzortung/america/index.php?bo_graph&bo_station_id=67&bo_dist=2098780&bo_time=2014-07-18+23%3A02%3A50.215459278&lang=en&bo_spectrum&bo_size=3)

(http://www.lightningmaps.org/blitzortung/america/index.php?bo_graph&bo_station_id=67&bo_dist=2098780&bo_time=2014-07-18+23%3A02%3A50.215459278&lang=en&bo_size=3)

This is the first strike where the signal appeared (5:02:50 pm EDT), and it's magnetic field only.  Since then, it seems to come on during the day, and off at night, and it's stronger in the A-channel (Red) ferrite than in the B-channel (Green).

Based on the orientation of the ferrites in my system and eyeballing the relative strength and phase of the signals in the H-field channels, it appears the signal is coming fairly consistently from a bearing along which a street light can be located (in the opposite direction is one of my neighbors, a little farther away).  It's a rough fix, but relatively consistent.

(https://lh3.googleusercontent.com/-iUaBimoBTxM/U8wNL1ZEn5I/AAAAAAAAAtQ/vNDD2H_nAWs/w959-h339-no/php_signal_2.png)

(https://lh3.googleusercontent.com/-wQZvSzhtlUE/U8wHT7NCUhI/AAAAAAAAAs4/1YS7sIlC4hk/w749-h567-no/BO_Int.png)

So, my question is, could this be from a malfunctioning street light?  The night/day consistency makes me think that's the issue, but I'm curious if anyone has run across any similar signals.
Title: Re: Interference and Noise
Post by: JonathanW on July 20, 2014, 11:03:04 PM
Ok,  turns out the answer was a lot simpler...  We have a couple of Toshiba LCD TVs at about the same bearing from the H-field ferrites (opposite direction from the street lights) .   The manual says the input HDMI connection uses about 25 kHz for 1080p input.   I'm guessing the  signal is mixing with an already present  25 kHz signal coming from somewhere else (maybe some cfl bulbs).   The 50 kHz signal only happens when both the TV and the converter are on.

By the way--a big thank you to Mike for setting up his auto-refresh signal tracking page.   It's a big help in tracking down problems!
Title: Re: Interference and Noise
Post by: meteo-melin on July 27, 2014, 06:07:02 AM
Hello,

Can someone give me tips about the noise of station 1104 region 1.
It seems that there is some noise in the 1kHz and 65kHz frequencies.

Thanks a lot,
Regards.
Title: Re: Interference and Noise
Post by: JonathanW on July 27, 2014, 12:36:33 PM
Good information from Tobi in a post about interference mode today.

Without, I think, resolving all questions regarding the interference mode thresholds (and I know the developers are still working on things), Tobi indicates that setting gains such that strike impulses are greater than 1.5Vpp may lead to clipping and signal distortion.  That can become an issue, of course, when a storm rolls over a station and gains aren't reduced, but can also be an issue in general.  Better to lower the gains and the thresholds (within reason).

Since the signal display on the controller page is relative (is this correct?), using the signal plots on Mike's auto-updating signals page will tell you whether your absolute signal levels are getting too high.
Title: Re: Interference and Noise
Post by: Knickohr on July 27, 2014, 12:45:21 PM
Isn't it implemented ?

Look at the drop down of "%good" at about -3h. It happens, when the storms are close to my station (<100km).

Station still not in interference mode  \:D/

Thomas
Title: Re: Interference and Noise
Post by: CF20852 on July 29, 2014, 10:06:19 PM
I'm still working on 60 Hz (and harmonics) interference here at Station 1093, North Bethesda, Maryland.  I decided it would be useful to rig up a way to be able to move my H-field antenna and Amplifier 12 around the house and listen to the Channel A and B outputs using earphones to see if I could find a quiet spot in the house.  (Sadly, all I've found so far is places that are more noisy than where I have the station set up.)  I bought an In-Line 1/8" Phone Jack, P/N 274-0274, from Radio Shack, and made up a two-foot-long single-ended Ethernet cable according to the T568A wiring convention (http://en.wikipedia.org/wiki/TIA/EIA-568).  On the Amplifier 12 control connector, pin 4 (T568A blue wire) is the AMP-B output, pin 5 (T568A blue/white wire) is ground, and pin 7 (T568A brown/white wire) is the AMP-A output.  I connected pin 7 (brown/white wire) to TIP on the phone jack, so AMP-A drives the left earphone, pin 4 (solid blue wire) to RING on the phone jack, so AMP-B drives the right earphone, and pin 5 (blue/white wire) to SLEEVE on the phone jack.  See http://www.connecthowto.com/20091227/connect-how-to-stereo-plug/ .  I'm still operating tethered to a 9V wall-wart powering a 5V linear regulator that in turn powers Amplifer 12 through the mini USB connector, but the next step is to power the 5V regulator from a battery.  The pot on Amplifier 12 works fine as a volume control, and with my earphones, I can get plenty of volume, probably enough to make a teenager cringe.

The attached photo shows the connections to the phone jack.  I have a stereo cable plugged into the jack in the photo.

As Don points out in his message below, it may be more convenient to attach the phone jack to the test connectors, depending on what you have in your junk drawers.  I happened to have a half-dozen Ethernet plugs, some Ethernet cable, and a crimping tool handy.

Of course, the bandwidth of this system is limited--given my age and exposure to rock concerts, airplane engines, small arms, and lawnmowers, maybe 10 kHz if I turn the volume up high enough.

Update 8/4/2014:  I implemented the battery power option and went on walkabout through my house yesterday afternoon, and found a reasonably quiet spot in the northwest corner of the house on the lowest floor.  It seems to be immune from the bathroom dimmer switch on the top floor, and the LED lights in the kitchen don't seem to interfere either.  There's still something, though...  But right now, at 5:20AM, my noise level is down to less than 60 mV pk-pk (as measured by the controller) and my gain settings are 16 x 4 x 40 = 2560.
Title: Re: Interference and Noise
Post by: dfroula on July 30, 2014, 09:05:24 AM
The test pins near the RJ45 connector on the amplifier board can also be used to wire in a 1/8" stereo jack, perhaps more conveniently. I found it best to connect a small headphone amplifier with a high-impedance input to prevent loading of the amp output and to provide impedance matching to the headphones.

I also found that connecting long leads to the output pins on the amp (for monitoring on an oscilloscope, for example) can produce oscillations in the op-amps when a lightning pulse is detected.

Don
WD9DMP
Title: Re: Interference and Noise
Post by: bidouilleur on August 09, 2014, 07:58:55 AM
hello All, joined the system about 3 weeks ago in France (region1), have been plagued by 2 peaks and I can't find the origin at all.  Think I resoldered the 2 boards about 5 times, fooled around in the house with am radio, cutting electricity etc etc etc ... these 2 peaks are there and no way to get rid off them.
Also when I turn the antenna's the signal goes from one channel to the other, makes me think it is not HW related
I do have an electric fence about 300 yards away but we already tried turning it off, same result ...
Peaks are I'd say around 1 and 64 kHz ....

you can see it at http://wouters.fr/blitz/plaf.php?station=1104 in action, driving me nuts.


Living in little village with a few houses around, not even very close ...

would appreciate your thoughts and eventually an idea where to start digging for a solution ...
thanks
Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on August 09, 2014, 09:10:34 AM
hello All, joined the system about 3 weeks ago in France (region1), have been plagued by 2 peaks and I can't find the origin at all.  Think I resoldered the 2 boards about 5 times, fooled around in the house with am radio, cutting electricity etc etc etc ... these 2 peaks are there and no way to get rid off them.
Also when I turn the antenna's the signal goes from one channel to the other, makes me think it is not HW related
I do have an electric fence about 300 yards away but we already tried turning it off, same result ...
Peaks are I'd say around 1 and 64 kHz ....

you can see it at http://wouters.fr/blitz/plaf.php?station=1104 in action, driving me nuts.


Living in little village with a few houses around, not even very close ...

would appreciate your thoughts and eventually an idea where to start digging for a solution ...
thanks

I might suspect someone having a 64kHz security device nearby... you might try Google 64kHz to look for a possible device.  64kHz is used for a lot of things like that, security scanners, etc... sound systems, etc...
Title: Re: Interference and Noise
Post by: CF20852 on August 09, 2014, 11:46:38 AM
This photo shows the power line communications interference generated by an Enphase Energy Envoy communications gateway communicating with a set of Enphase microinverters.  The power line communications signals are to the left of center.

(https://lh5.googleusercontent.com/fdhfAsmmPbHNcUT0NNemb3NqX4PbFZQiEOjiV4CxdA=w1270-h695-no)
Title: Re: Interference and Noise
Post by: bidouilleur on August 09, 2014, 03:47:47 PM
will have a look for alarms around, we don't have any for sure

and the line interference, I see these generally around 6 am and 10 pm when we get the signals to go to night or day prices ... but that is only for a minute or two
Title: Re: Interference and Noise
Post by: CF20852 on August 16, 2014, 07:12:02 PM
This:
(https://lh4.googleusercontent.com/1RmcTx-0A2WH4ZTU_-CaZn7zOvMv1i9a3gSVovFhww=w1013-h484-no)

Seems to be caused by this, between my back-fence neighbor's garage doors:
(https://lh4.googleusercontent.com/-RuFpH1-8Gq9LCnCJTlElZ7RqOdeP_hhMtq17nB0Yw=w495-h364-no)

Here's a spectrum plot of the above waveform:
(https://lh5.googleusercontent.com/-h7GTLBAu624/U_CjAYO_m0I/AAAAAAAABD8/yslOl13j2lk/w1517-h537-no/Spectrum%2Bof%2BDamped%2B60%2BHz%2BHarmonic%2BPulse.jpg)

Or it could be that fluorescent light in combination with the other two my neighbor has on the front of his house...  #-o

The interference appears when my neighbor's outside lights come on at about 6PM and disappears when they go off at about 11PM.

My wife wanted to know why I had to go over there and take a picture, so I explained to her that I was documenting an interference problem and I might offer to swap out one of the neighbor's lights.  She rolled her eyes and muttered "oh, please..."

The things we do for science.   ](*,)

The red channel line at 24 kHz is probably NAA in Cutler, ME, which you don't see in the waveform plot because although the green waveform is the same signal as represented in the spectrum plot, the waveform image and the spectrum image were captured at different times.
Title: Re: Interference and Noise
Post by: JonathanW on August 17, 2014, 09:38:13 AM
Yep.  I've noticed a consistent ~24 kHz interference signal from GE-brand Reveal CFLs.  I'd imagine many (most?) integrated CFLs have electronic ballasts that operate at a similar frequency.

I use CFLs far from my BO probe, and incandescents near.  I haven't tried LED bulbs yet.
Title: Re: Interference and Noise
Post by: miraculon on August 17, 2014, 02:26:59 PM
Yep.  I've noticed a consistent ~24 kHz interference signal from GE-brand Reveal CFLs.  I'd imagine many (most?) integrated CFLs have electronic ballasts that operate at a similar frequency.

I use CFLs far from my BO probe, and incandescents near.  I haven't tried LED bulbs yet.

I have a LED bulb in our bedroom. When it is on it creates a lot of hash noise on the NOAA weather radio nearby. I realized that this is 162.55 MHz and not our frequency range of interest.

These noise problems seem to be getting worse.... ](*,)

Greg H.

 
Title: Re: Interference and Noise
Post by: JonathanW on August 20, 2014, 02:14:47 PM
As Chip mentioned:

http://en.wikipedia.org/wiki/VLF_Transmitter_Cutler (http://en.wikipedia.org/wiki/VLF_Transmitter_Cutler)

I'd bet this 2 MW beauty is the source of the 24 kHz signal I've consistently seen since I started operating my station.
Title: Heterodynes of AM Broadcast Stations
Post by: b.e.wilson on September 15, 2014, 11:16:18 AM
If you have some very loud local AM broadcast stations, both of which are within about 100 KHz of each other, they can mix in the first gain stage to give a heterodyne signal when the first gain stage is amplifying. This signal will have a carrier frequency matching the difference in the two AM station frequencies. In the example below, I have two stations, 1450 and 1400 KHz, each at S9+40dB, mixing in the first gain stage (when the gain is set at 8 or higher) to give a 50 KHz heterodyne. Modulating this heterodyne are the audio modulations of both AM stations, one at a low frequency (the broad up-down movement, I think) and one at a high frequency (the vertical expansion and contraction of the envelope).

In the frequency plot you can see the 50 KHz heterodyne, with audio sub-bands on either side, as well as the pure audio frequencies at low frequencies below 10 KHz. I don't have an explanation for the 30 KHz or 80 KHz signal, but they may be related (0 KHz + 30 KHz = 30 KHz; 50KHz + 30 KHz = 80 KHz).

Diagnosis: go to manual and set the gain of the first amp stage very low, in my case 1 or 2. This makes the first gain stage far more linear and the mixing of the signals is eliminated. The second gain stage is immune to heterodynes as it is amplifying the bandpass-filtered signal.

EDIT: Solution. In my case, the loop antennas had a self-resonant frequency close to the 1400 KHz interfering frequencies. The loop antennas, then terminated with a high resistance value (R1 and R16, 2.2kOhm), had a high Q value, so they became very efficient at pulling in that signal. Richo (project dev) suggested I lower the value of R1 and R16 to 100 Ohms. I used resistors I had on hand, 150 Ohm, and the intermod disappeared at all first-amp gain settings. By using a lower-valued termination resistor, the value of Q for my loop antennas was dramatically reduced, flattening the frequency response curve, and thus the efficiency of the loops at the resonant frequency. This should be considered the proper solution to an intermod problem. Lowering the first-stage gain is a diagnostic method and temporary solution only.
Title: Re: Interference and Noise
Post by: dwmatt on October 05, 2014, 04:56:50 PM
Finished my build and hooked everything up.  Getting really bad interference and can't tell if it is internal to the unit or external.  I've been running around with an AM radio to see if I can find anywhere in my house that isn't noisy (having a hard time with that.)  I think part of the problem is the crappy USB wall-wart I am using (which will be replaced asap,) and the other part is distance between the controller and the amplifier (need to get a 75ft shielded cable asap as well.)

I don't see any sine waves on the rogue gallery, but my 1A channel periodically sees a long sine wave, my 1B channel sees a 60hz wave, and I've grounded the controller (but not the amplifier.)  I know that some of the noise I am seeing right now is the electric company's smart meter (which I shouldn't see when I move the amplifier to its ultimate location about 50ft away from the smart meter.)

What is really weird is I'll see a good couple minutes of clear, with one or two strikes per minute, then a few minutes of 60/s per minute, then clear, then 60/s per minute.  Interference mode seems to activate every few minutes.  Won't start submitting my data until I get a better handle on the noise.
Title: Re: Interference and Noise
Post by: miraculon on October 05, 2014, 06:39:51 PM
Finished my build and hooked everything up.  Getting really bad interference and can't tell if it is internal to the unit or external.  I've been running around with an AM radio to see if I can find anywhere in my house that isn't noisy (having a hard time with that.)  I think part of the problem is the crappy USB wall-wart I am using (which will be replaced asap,) and the other part is distance between the controller and the amplifier (need to get a 75ft shielded cable asap as well.)

I don't see any sine waves on the rogue gallery, but my 1A channel periodically sees a long sine wave, my 1B channel sees a 60hz wave, and I've grounded the controller (but not the amplifier.)  I know that some of the noise I am seeing right now is the electric company's smart meter (which I shouldn't see when I move the amplifier to its ultimate location about 50ft away from the smart meter.)

What is really weird is I'll see a good couple minutes of clear, with one or two strikes per minute, then a few minutes of 60/s per minute, then clear, then 60/s per minute.  Interference mode seems to activate every few minutes.  Won't start submitting my data until I get a better handle on the noise.

I have two suggestions that might help. (or may not, but they are worth checking)

1: Log-in to the controller and select the "Signals" tab. Below the "oscilloscope" charts, there is a button labelled "5V Sampling" in the Signal Tools area. Enable it and the display will switch over to a power supply monitor. If your Peak-to-Peak noise is more than a millivolt or two, you need to look for a cleaner supply. (there have been some suggestions here in the forum.) Remember to disable the 5V monitor if you want to look at antenna signals again.

2: Disable the PWM for the display backlight. There are several ways to do this, either time-outs or just setting it to 100% duty cycle. This is under "Settings" tab, "Buzzer/LCD" sub-tab. Under the "LC Display" option, the first item is "Brightness". The PWM for the display is a known noisemaker and it is best to go to 100% or 0%. You can also set it to turn off after a time period. I was using this for a while, but I leave mine at 100%.

From your description, it sounds like you have the amplifier connected via UTP vs. the needed shielded STP Cat5. When you get your cable test continuity on the shield with a meter if you have one (or a Cat5 tester). I got a defective STP cable that caused me problems before I figured out that it was bad. The grounding of the controller probably won't do much if you are using UTP Cat5.

Also, is it possible you have in intermittent connection on the antenna to the connector block? Also check your solder connections on the SOIC8 PGA amplifier ICs. A microscopic void in the solder joints can cause problems.

Good luck hunting it down.

Greg H.






Greg H.
Title: Re: Interference and Noise
Post by: dwmatt on October 05, 2014, 06:53:45 PM
I replaced the cable with a shielded cable, but didn't see any improvement (though I now moved it out of the computer room and to a far quieter area.)  Removed the solder with a wick from SIOC8, resoldered SIOC8 and then SIOC1, and now I am getting 16x10x40 gain on both channels, with no high noise, but I am not sure it is working as I can see what appears to be small magnetic interference from two speakers 30' away (not enough to trigger, but I see the freq changing as the speakers get louder/quieter, but no 60hz and the 1st channel isn't doing a long sine any more.)

However, I am also strikes on LightningMaps, and my controller isn't seeing any of them, even though I should see them (others in California, far north of me are.)  Maybe I busted it instead of fixing it.  Those SIOCs are tricky.  Wish there was an easy way to unsolder them and resolder them without a lot of heat to potentially damage them or the components around them.

*Another Update: Fixed.  I've been recording strokes, and even though my gain isn't to my liking yet and there is still a lot left to do, the amplifier appears to be working properly.  Now if I could just find the source of the noise at dusk and dawn...someone has a sodium lamp around here, probably the school, and it is pushing 60s/s every evening as the lamp warms up.  Oh well.
Title: Re: Interference and Noise
Post by: uhf on October 14, 2014, 10:07:22 PM
I have no idea what I'm doing. It appears I have some sort of interference, but most of the time the web gui causes my browser to crash. There has to be a better way to troubleshoot. Anyone have any idea what this chart means??

Title: Re: Interference and Noise
Post by: uhf on October 14, 2014, 10:09:46 PM
Another one, this is more typical.
Title: Re: Interference and Noise
Post by: W3DRM on October 15, 2014, 01:02:25 AM
Just got my November issue of QST and it has a nice article in it about RFI (Radio Frequency Interference) on HF. In the article there is a reference to some information on power-line noise. It can be found at http://www.arrl.org/power-line-noise-faq (http://www.arrl.org/power-line-noise-faq). NOTE: This link is good for anyone whether you are an ARRL member or not. If you are a Ham and a member of the ARRL, you can see the article in the Nov 2014 issue of QST starting on page 33. The article also describes the design, building and usage of a direction finding system. ARRL members with on-line accounts may access the November issue of QST at the following link: http://www.nxtbook.com/nxtbooks/arrl/qst_201411/index.php (http://www.nxtbook.com/nxtbooks/arrl/qst_201411/index.php). Non-ARRL members will not be able to see this article - sorry.

If I can find some free time (ha-ha) I may just try to build one of these myself and see how it works.
Title: Re: Interference and Noise
Post by: W3DRM on October 16, 2014, 07:40:00 PM
Well, I just found the perfect place for an Ortunger to live - Green Bank, West Virginia - it is within the National Radio Quiet Zone. Watch the video for details.
This would drive some folks nuts not being able use all of their electronic gadgets but Blitzortung would be quite at home there...
Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on October 16, 2014, 07:49:38 PM
Another one, this is more typical.
Yep;... buncha line freq interference... check for old, ageing street lamps. dimmer switch, household appliance, nearby motors....
Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on October 16, 2014, 08:01:21 PM
Well, I just found the perfect place for an Ortunger to live - Green Bank, West Virginia - it is within the National Radio Quiet Zone. Watch the video for details.
  • https://www.youtube.com/watch?v=iTVLJeRQS5c (https://www.youtube.com/watch?v=iTVLJeRQS5c)
This would drive some folks nuts not being able use all of their electronic gadgets but Blitzortung would be quite at home there...
Yep, the "black hole'... would you believe that KFFT apparently has reactivated a NDB just over the hill from me?  Sheesh... talk about dark ages....  yeah,
Title: Re: Interference and Noise
Post by: miraculon on October 16, 2014, 09:52:44 PM
Either there or the VLA on the Plains of San Agustin in New Mexico. We visited there in 2000. It is also a NRAO http://www.vla.nrao.edu/ (http://www.vla.nrao.edu/) site. It is out in the middle of nowhere.

Greg H.
Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on October 16, 2014, 10:09:44 PM
Meditating line freq is part of the fun of this thing.. first, make sure ONLY the controller block has a good "cold water" ground.... finding that "sweet spot" took me some time........  get an AM radio, tune it off station.... somewhere 530 -645 kHz... and find a location where it's minimum.... try your antennas there... my 'sweet spot' is about 2 meters high and 2 meters wide... it can be that critical in locations like mine !...and I've a tough M component environment! If I can mitigate it, anybody can, 'cause I'm not that bright! But even a blind hog finds an acorn if he roots long enough... .
 
Title: Re: Interference and Noise
Post by: uhf on October 16, 2014, 10:23:26 PM
Another one, this is more typical.
Yep;... buncha line freq interference... check for old, ageing street lamps. dimmer switch, household appliance, nearby motors....
Dishwasher is making a lot of the noise, as are two dimmer switches. The dimmers are going bye-bye. Don't know what I'm doing about the dishwasher, but I have some ferrites that I might try on the power leads. My antenna is also located fairly close to the electric meter, which probably isn't the best spot, but at times it's very quiet there and it's the perfect spot convenience wise for me to mount the antenna, so I'll leave it there if I can.
Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on October 16, 2014, 11:18:41 PM
Another one, this is more typical.
Yep;... buncha line freq interference... check for old, ageing street lamps. dimmer switch, household appliance, nearby motors....
Dishwasher is making a lot of the noise, as are two dimmer switches. The dimmers are going bye-bye. Don't know what I'm doing about the dishwasher, but I have some ferrites that I might try on the power leads. My antenna is also located fairly close to the electric meter, which probably isn't the best spot, but at times it's very quiet there and it's the perfect spot convenience wise for me to mount the antenna, so I'll leave it there if I can.
Great!  You're on the way,,, the network and you both can survive the dishwasher at it's odd times... the dimmers are a different matter...  you might even find a 'sweet spot' to minimize the dishwasher,........ just  takes some trial and error,..   might have to move it away from the 'mains' meter, if possible... my location isn't the most 'convenient'... but it's the best... and it is a PITA but it's all I've got  ](*,) at least for H field...  my e field fairly comfortable/.....
Title: Re: Interference and Noise
Post by: dwmatt on October 17, 2014, 11:25:04 AM
I found one of my sources of interference.  I have an E-Wave detector from HobbyBoards that would go off every day about 8am, and I couldn't figure out why.  Then, setting up my Blitzortung H-Wave, I'd see the same interference at the same time.  This morning, I was getting tons of signals (8-40 a second), and started looking around.  Everything was in the 10kHz range.  Opened up the door and heard the school next door giving a fairly long PA announcement.  Every time the speaker would stop and clear the mike, the signal would stop, then would start back up the moment he would start speaking.  The bells don't seem to set off the detectors, just the announcements.  Attached is one of the waveforms I am seeing.

Argh!  Luckily, it only goes of predictably every morning, so I can set up a cron job to disable sending at 7:55am and re-enable it about 8:30am.

Title: Re: Interference and Noise
Post by: 92merc on October 17, 2014, 11:33:19 AM
Where did you get the E-Wave detector?  I wouldn't mind getting one to track down some intermittent interference I see.
Title: Re: Interference and Noise
Post by: miraculon on October 17, 2014, 11:38:22 AM
I found one of my sources of interference.  I have an E-Wave detector from HobbyBoards that would go off every day about 8am, and I couldn't figure out why.  Then, setting up my Blitzortung H-Wave, I'd see the same interference at the same time.  This morning, I was getting tons of signals (8-40 a second), and started looking around.  Everything was in the 10kHz range.  Opened up the door and heard the school next door giving a fairly long PA announcement.  Every time the speaker would stop and clear the mike, the signal would stop, then would start back up the moment he would start speaking.  The bells don't seem to set off the detectors, just the announcements.  Attached is one of the waveforms I am seeing.

Argh!  Luckily, it only goes of predictably every morning, so I can set up a cron job to disable sending at 7:55am and re-enable it about 8:30am.

This is an interesting one. I suspect that the noise is the audio radiating from either the speakers or building wiring for the speakers. I worked for "famous maker auto company" years ago. We had an issue where 610KHz AM noise was coupling from the speaker voice coil to the AM antenna in the rear defroster grid. It was a harmonic of the DSP subsystem.

It might be harmonic distortion from the voice clipping into our band. 3rd/5th order harmonics from voice could fall right where it could be picked up.

Greg H.
Title: Re: Interference and Noise
Post by: dwmatt on October 17, 2014, 11:59:49 AM
Where did you get the E-Wave detector?  I wouldn't mind getting one to track down some intermittent interference I see.

HobbyBoards Lightning Detector, http://www.hobby-boards.com/store/products.php?product=Lightning-Detector.  Only counts signals it receives, so probably not helpful for tracking down interference.
Title: Re: Interference and Noise
Post by: miraculon on October 17, 2014, 01:02:02 PM
I have the H-B lightning detector, not currently connected. It is a "One-Wire" unit that requires a computer side interface and supporting software. (Weather Display supports it, and some Linux-based applications like OWW).

I wouldn't think this would be practical as a detector/sniffer for noise sources. Mine had to be grounded to a cold-water pipe ground to work at all, even with local lightning. The range was somewhat limited, which is not a surprise since it is not tuned and is a simple Darlington transistor-pair circuit. I ran it for several years prior to getting into Blitzortung, and when we moved I decided to retire it.

I have a variety of EMI "Smog" meters, etc. but the most effective E-field sensor I have is the "Natural Radio" receiver. I bought it primarily to find noises, but it's intended purpose is listening to "whistlers". It is not cheap, but works very well. I bought a pair of Stanton headphones with a HPF that minimizes 60Hz pickup, which is filtered out by the E-Field amplifier quite well.

Here is a link to the radio: http://www.auroralchorus.com/wr3gx2.htm (http://www.auroralchorus.com/wr3gx2.htm) I see that Stephen how has an H-Field receiver in the works as well. http://www.auroralchorus.com/ (http://www.auroralchorus.com/) This H-Field one doesn't seem to be portable enough to use as a noise sniffer though.

There is also this one, but I don't have any experience with it. http://theinspireproject.org/ (http://theinspireproject.org/)

Greg H.
Title: Re: Interference and Noise
Post by: uhf on October 17, 2014, 10:07:20 PM
Would something like this work to find interference?
https://play.google.com/store/apps/details?id=com.superphunlabs.emf&hl=en
Title: Re: Interference and Noise
Post by: miraculon on October 18, 2014, 11:34:55 AM
Would something like this work to find interference?
https://play.google.com/store/apps/details?id=com.superphunlabs.emf&hl=en

Interesting, I wonder if it is really used for some kind of noise cancellation for phone calls. Would a tablet/pad also have this sensor? I might try loading it. If I don't get anything, I would conclude that the pad doesn't have the sensor.

Greg H.
Title: Re: Interference and Noise
Post by: corwyyn on October 19, 2014, 12:55:06 AM
Would something like this work to find interference?
https://play.google.com/store/apps/details?id=com.superphunlabs.emf&hl=en

Interesting, I wonder if it is really used for some kind of noise cancellation for phone calls. Would a tablet/pad also have this sensor? I might try loading it. If I don't get anything, I would conclude that the pad doesn't have the sensor.

Greg H.
Greg I know my galaxy tablet has the magnetic sensors because every time I  start up one of my planetarium programs it tells me there are unusually strong magnetic fields present if I'm say sitting in my car.  Might download it and try it at home this weekend.
Title: Re: Interference and Noise
Post by: miraculon on October 19, 2014, 12:36:28 PM
When I installed it on my El Cheapo tablet, it complained about the missing sensor. So, I guess that it is not an option for me, unless I eventually upgrade my mobile....

Greg H.
Title: Re: Interference and Noise
Post by: Silversword on October 19, 2014, 03:22:03 PM
Would something like this work to find interference?
https://play.google.com/store/apps/details?id=com.superphunlabs.emf&hl=en

Hi All,

I installed both this one and the Ultimate one on my Motorola Xoom table.  It seems to be working but I don't understand what is going on with the readings.  It does change when I move around the house but too significantly.

No chance to go outside with it as Hurricane Ana was passing by and there were some lightning activity around my location.  Guess no one from the West picked it up as I did not see anyone getting a line over here.

Survived the storm without any issues at my location.

--Stan Y.
   Maui, Hawaii
Title: Re: Interference and Noise
Post by: W3DRM on October 20, 2014, 11:10:12 PM
I tried to download the app onto my Android phone but I received a warning saying it was "Adware" so I aborted the download. Did anyone else get such a warning?
Title: Re: Interference and Noise
Post by: corwyyn on October 21, 2014, 02:20:27 AM
I tried to download the app onto my Android phone but I received a warning saying it was "Adware" so I aborted the download. Did anyone else get such a warning?
I noticed that, decided to try it anyway.  When it first opened up it mentioned that it would also place an icon on the phone to link you to more of the company's apps.  When closing it out every time it would ask if I wanted more of their apps so after the 3rd time using it I decided to uninstall it - I went with this one instead: https://play.google.com/store/apps/details?id=com.codebros.emffree&hl=en  Note that this one is also 'adware' but it isn't nearly as annoying as the one from superphunlabs (A division of Venture Industries no doubt  :roll: ) and if it seems to work OK then I'll spring for the two bucks for the full version.
Title: Re: Interference and Noise
Post by: uhf on October 21, 2014, 05:36:05 PM
Sorry, guys. I didn't install the app before posting about it, and I should have tested it first. My bad.
Title: Re: Interference and Noise
Post by: W3DRM on October 22, 2014, 01:47:22 PM
I've been poking around looking for some Android apps that handle EMF measurements and have come across a couple items that may be of interest to the group.

I have an app on my Samsung Galaxy S5 named CPU-Z. It lets you view all kinds of information about the cpu. It can be found in Google Apps as follows:
While looking through the various CPU-Z tabs that are loaded with info, I stumbled on two fields under the SENSORS tab. They are AK09911C Magnetic field Sensor and AK09911C Magnetic Sensor UnCalibrated. The readings shown are 44.3 T and 55.1T respectively. T stands for micro-Teslas. These readings match what I see on another EMF app named EMF Sensor Free which is also available free in the Google Apps store.
Unlike the EMF Meter by SuperPhunLabs, I don't get any warnings or apparent issues while running EMF Sensor Free. There is a paid version available that gives you additional options and ad-free viewing. The ads are on the bottom of the screen and are not too intrusive.
Title: Re: Interference and Noise
Post by: Einar on October 24, 2014, 03:16:36 PM
The data sheet for that sensor suggests max sampling speed is 100s/s. Maybe enough for hunting ghosts, but not EMI.
Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on October 24, 2014, 10:20:47 PM
Here's the deal... if you can't find it with an AM radio for H field,. . why waste all this time with these '''apps"""   why not get a TriMeter, http://www.amazon.com/gp/product/B00050WQ1G/ref=oh_aui_detailpage_o09_s00?ie=UTF8&psc=1, or professional system, and be done with it???? You'll  never mediate it in any auto mode, or with "what's causing this" anyway... you'll have to do like us old timers.... find it, mediate it, or live with it.... ///

How 'bout no more PHONE APPS of doubtful efficiency in this thread????
Title: Re: Interference and Noise
Post by: uhf on October 28, 2014, 09:05:58 PM
I guess I need to find an AM radio. I doubt I have a battery powered one.
Title: Re: Interference and Noise
Post by: Einar on October 29, 2014, 06:07:39 PM
I'm still trying to eliminate 50KHz noise burstst at 100Hz rate. (We have 50Hz mains here.)

I put copper mesh shielding around the 250mm ferrite antennas. That helped a lot. Now I just was up in the attic and wrapped the ferrite antenna leads tightly around the wire going from the antenna shield to the amplifier. That made some difference. The noise amplitude is about halved. I had my surfboard with me so I could look at the signal and it went off the scale while I was touching the antenna leads. Which to me indicate the signal is actually E-field.

So my next attempt will be to skin a coax and put the antenna leads inside the braid so it is completely shielded from the antenna shielding up to the inputs of the amplifier. That should avoid exposing those wires to the E-field as much as I can.

Did anyone try this before? If so, what was the result?

This is station 1209.

I tried turning off everything here except what is needed to run the BO without making any difference. It does seem to be there 24/7. One thing it could be is the overvoltage protection in the main breakers cabinet. But I cannot easily disconnect that. Does anyone have identified problems with those making a "ringing" on the mains?
Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on October 31, 2014, 12:21:21 PM
Einar, Go back to square one... make the H field leads as short as possible. Remove your shielding and undo any 'loops' in the antenna connections to the amplifier.   Now, I have a very noisy H field environment, and it took me several weeks to find the only 'sweet spot' with minimal interference. You may have to do something similar. I still have issues, and have to run with reduced gain. Since most of my EMI is M type, I cannot run within my system's capability, on H field...
We all have a hard time getting past that "distance" range thinking... see if you can optimize best for <500km (300mi) and you'll work great with the network.
Simplest way is follow EMI with an off station AM radio (530 or 10KHZ) until you find quietest spot... then go from there.  Also, the line freq EMI will change seasonally!  And with daylight/dark hours!  We deal with 60Hz junk here in the US, but issues are similar...  If your EMI is M type, shielding, all the other junk, won't mediate at all....
Mike
Title: Re: Interference and Noise
Post by: Einar on October 31, 2014, 04:42:14 PM
M-type? What is that?
Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on October 31, 2014, 05:24:25 PM
M-type? What is that?

Magnetic... whether Near Field H field magnetic component, or generated 'in space' by a large Electrical discharge, or simply by a moving magnet nearby... Might be a better definition somewhere, but you could say it's "H field" to simplify... however M could also be caused by rotating a magnet nearby, and not be a true 'EM" signal... if you follow me.  So I use "M" because I'm not exactly sure of source, perhaps, but do know that it's "Magnetic"  not "Electric"... there are some 'sources' that consider "H Field" as a more complex plane of force than "E" Field, and refer to "M" as an "H field component" or similar...  However it's implied or defined, an "M" with motion, or changing strength, cannot be shielded on an H field Horizontally polarized antenna... It's gonna induce 'current' and therefore voltage, in a receiver's front end.  Since the "M" (H) is typically "Horizontal"... an E field "Probe" (vertical) is more or less immune to "M" (H) field.  An "H" field (horizontal) antenna can, however, be shielded from some "Electrical" (E field) signals, which might have a very weak (because of distance) "M" component.... the idea is to mediate "opposite" planar current/voltage induction into the receiving element... and only detect the 'plane' we're aiming for -- "E" (Electric) "H" (magnetic)... with "M" being a possible "Magnetic" source from (wherever) that we don't desire.... arrrrrrrggggggghhhhhhh.......
Confused?   Yeah, me too...  #-o  and I probably have some of this wrong... oh, well.....   :twisted:
I Think....  :twisted:
Mike
Title: Re: Interference and Noise
Post by: Einar on October 31, 2014, 06:27:00 PM
You should buy this book: http://www.bicon.nl/emc-book.html

It's really good reading!

And I found the source of my noise! It is my Samsung laser printer. Guess I have to try quieting down the rectifier. That should be possible to get rid of. For now switching it off will have to do. The noise is completely gone. All I see now it that it's getting cold, and thermostats click on/off in east, south, west and north.
Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on October 31, 2014, 06:42:32 PM
You should buy this book: http://www.bicon.nl/emc-book.html

It's really good reading!

And I found the source of my noise! It is my Samsung laser printer. Guess I have to try quieting down the rectifier. That should be possible to get rid of. For now switching it off will have to do. The noise is completely gone. All I see now it that it's getting cold, and thermostats click on/off in east, south, west and north.

Yeah, I sympathize with the Laser Printer.. I gave a brand new ACER, top of the line, PC to my son because it radiated so much it messed up BO.... I've got 8 HP pcs, and 2 laptops that don't interfere, unless the oldest laptop is within about 15' of the H Field....
Outstanding that you found it!   Feels good, doesn't it! =D&gt;
That's part of the fun... this 'interference' with what we used to call 'interference' when DXing or listening to radio~

Thanks for the tip on the book,.... but the issue with me is I've (at my age) forgotten more than they teach today about such things.... and my 'grey' cells have turned to 'grey hair' ... you should hear 'em scream when one falls out...   too much learning curve anymore... and not enough life expectancy to learn and absorb much more... Hell, I remember when "Siemens" were 'Mhos", unless I've forgot it...   Probably get that wrong also...
Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on October 31, 2014, 07:23:31 PM
Einar... if you've got a screen shot or two of that printer EMI when active, why not post 'em here????   Might help folks...
Mike
Title: Re: Interference and Noise
Post by: Einar on November 01, 2014, 01:32:47 AM
Of course, here they are. 2 screenshots with a few minutes between them. No change in amplifier settings.

Also a screenshot from a scope showing a longer sampling in the time and frequency domain. Notice that the bursts are reocurring at 10ms intervals, and our line frequency is 50Hz. The noise itself is 49-50KHz. This variation is probably temperature dependent, as it is stable for long time intervals. The scope was connected to the output of chA on the H-field amplifier. I don't remember the amplification setting at that moment, but I think 400 or so.

And yes, it should be helpful as it is typical for anything that have a rectifier bridge feeding a capacitor. Which in practice means almost every appliance available today. You just have to find the offender and hope it is within your reach to turn off.

It should be possible to quench this noise by either modifying the line filter or maybe just drilling a hole in the plastic case to access the chassis and ground it properly. Something that should not be done without checking the safety aspects of it though. If touching the ground and the printer chassis at the same time before they get connected might lower your heart rate to zero.

Regarding the grey hair, you just may underestimate my number of grey hairs. Although they actually are getting fewer in number. Learning is harder when getting older, but as fun as before.
Title: Re: Interference and Noise
Post by: Einar on November 05, 2014, 03:54:04 AM
Are there any explanations her on the different station statistics on Blitzortung.org?

I believe my station (1209) is pretty Level now, but several of the Statistical graphs I don't really understand.

We're into the Cold season With lots of heater thermostats switching, so I think the noise that is there now is something I cannot do much about. And I *believe* the statistics support that. But I would rather like to be able to exploit the data better than I can do without really understanding what they mean.

Title: Re: Interference and Noise
Post by: WA7FWF on November 10, 2014, 10:39:23 PM
Well things seem to be working good here, picking up strikes off the east coast as I type, but there is a noise I can't seem to track down, mostly at night but I have seen it during the day, what is odd  is the waveform spans magnetic and E and looks pretty weird. I'm posting a pic in hopes someone says hey! I have seen that one before, fortunately at this point its pretty intermittent.

Thanks
Kevin
Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on November 11, 2014, 02:36:23 PM
First of all.. the image shows very high gains... which aren't really necessary... resulting in what appear to be distorted waveforms in E channels... Those signals are likely to be rejected.   Second there's no real advantage for 'network' operation to detect signals 5000KM away..., there are other stations who provide a more 'accurate' TOA TOGA, and signal representation...
My suspicion is you're operating in "automatic"  with a few filters switched in.   My suggestion would be to "restart" optimization by following our experience at http://www.wxforum.net/index.php?topic=22710.0 which deals specifically with running a Dual Field system... based on the 2014 Red System...
You're looking good.... system looks quiet, and with 'illustrated' signals coming at such Hi Gains, you will probably have an excellent station...  :-(.. unlike mine... I've similar interference and it's much much closer, apparently, than yours... so I can't run at your capability...  In both cases the signals have a strong Line frequency emission, with spikes,... so your signal may in fact be a tad weaker than mine, you appear to have strong "Near Field" magnetic, plus very strong electric arcing...  hard to tell without FFT signals, and some other data...
Welcome aboard!
Mike
Title: Re: Interference and Noise
Post by: WA7FWF on November 11, 2014, 03:31:59 PM
  Mike your correct on many points, it is running automatic with filters, when I can be around for awhile and something good is brewing I will put it back into manual,  and I have gone with the setup link for H and E  and I get everything set and its great and then I come back later and its almost in interference mode or I am seeing nothing.  I'm also definitely in newbie mode learning, so if I'm not going to be around  I leave it in automatic even though I know that is not optimum but I figure its "safer".
  I wondered if the odd waveform was from clipping in the amps and I guess so, I could turn everything down and leave it real low but then I miss a lot of things that other stations nearby see, I was trying to find a sweet spot where I see a good bit  while not putting 20,000 signals to the servers, just trying to get a better feel and understanding which settings are better, right now even with it in automatic it tends to stay around 500 for signals  but then noise in the neighborhood kicks up and I will see it in the 3000's for signal. I have never seen anything for what an excessive amount of bad signals might be.

Thanks
Kevin
Title: Re: Interference and Noise
Post by: CF20852 on February 15, 2015, 11:56:46 AM
The U.S. Federal Communications Commission has an on-line table of frequency allocations at http://transition.fcc.gov/oet/spectrum/table/fcctable.pdf that some folks might find useful for identifying possible sources of interference.  The International Telecommunication Union's (ITU's) international allocation table from Article 5 of the ITU Radio Regulations is on the left, and the U.S. Federal (controlled by NTIA) and Non-Federal (controlled by the FCC) allocations from the FCC Rules, 47 C.F.R. Section 2.106, are on the right.  Attached below is a snapshot of the U.S. side of the table, for the frequencies from 9 kHz to 90 kHz.  The footnotes are important, for example, US2:

"In the band 9-490 kHz, electric utilities operate Power Line Carrier (PLC) systems on power transmission lines for communications important to the reliability and security of electric service to the public. These PLC systems operate under the provisions of 47 CFR part 15, or Chapter 8 of the NTIA Manual, on an unprotected and non-interference basis with respect to authorized radio users. Notification of intent to place new or revised radio frequency assignments or PLC frequency uses in the band 9-490 kHz is to be made in accordance with the Rules and Regulations of the FCC and NTIA, and users are urged to minimize potential interference to the extent practicable. This footnote does not provide any allocation status to PLC radio frequency uses."  Unfortunately, we Blitzortung operators are not "authorized radio users".
Title: Re: Interference and Noise
Post by: geewizard on March 27, 2015, 05:20:10 PM
I'm new to this sferics thing and finding the MANY sources of interference.  I'm not new to electronics, radio, etc.

That said, I've got these big noise spikes at 60kHz and about 125kHz.  The one at 125 kHz is persistent.  Are they harmonics or something of a 30.5 kHz signal?

Any ideas?
Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on March 27, 2015, 07:02:35 PM
Watching your sigs for awhile on the Hi res at http://sferics.us ,
and I think you've got at least 3 separate disturbers... about 30kHz, 60kHz and 80kHz.
I think the 120 might be a 'mixing' artifact.  The 60kHz is strong, and probably localize.
You're also running 8*16 gains, so you might see what things look like at 10*10 or even 8*8.
either way, the server seems to have no problem with the disturbers, though it gives you a
higher signal count... so what, no big deal.

To me, they have all the appearance of localized electronic devices, timers, computers, something nearby.
Security system, similar... .
However, in the end, you may likely find this all related to the Jim Creek Naval transmitter, about 280 miles
west of you. At a million+ watts and a humongous ground system... And who knows what goes on in and around Fairchild, also west of you...
But I think it's local... in your home or nearby.
Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on March 28, 2015, 11:03:00 AM
Lighting ballast drivers like to run at 62kHz
Some Monitors, especially LG, like 61kHz
Some Pest repellent like 32-62kHz
Some Printers like to run at 62kHz
Lots of AC-DC converters, ditto.
Your neighbor has a big mobile Camper/ trailer on constant charge????
Title: Re: Interference and Noise
Post by: geewizard on March 28, 2015, 11:10:15 AM
Thanks Mike.

Are those spikes affecting my contributions or can I ignore them?

Could the 60 kHz be WWVB?
Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on March 28, 2015, 04:43:01 PM
All the way from Ft. Collins?  Don't think so, but anything could be possible... Who knows what could flow up the mountains and through that big Yellowstone Magma chamber between you. 
I think it's local... a fluorescent or something.  I had a high end ACER computer last year... could not run it in the house, it radiated so strongly.  Matter of fact, I gave it to my son, who lives in Fort Collins.  :-k ....I'd rather think it's that damned ACER interfereing with you than WWVB. I could tell him to unplug it, and see if your EMI goes away  :twisted: Getting it 1250 miles away from me eliminated my issues with it.

Start pulling breakers, see if you can make it go away, or at least discover which leg of your residential ac service might be driving it.
As for the usage of signals.... as long as you keep your controller out of interference mode, you'll send signals. The server will ignore that, it'll just give you a higher signals count... It doesn't look like lightning, and the server know it isn't.  Yeah, you might miss an actual stroke once in awhile, but we all do. Lots of stations, especially in Europe with all the NATO mil traffic, especially sub comm, the strange regulators etc they have for solar power, etc... they get along fine.
Just wait for spring, and watch the forums when folks start firing up those robotic lawnmowers!  They drive operators nuts! And they're on power 24/7 since they stay plugged in to charging station!
Title: Re: Interference and Noise
Post by: geewizard on March 29, 2015, 11:01:14 AM
From what I read on the NIST site regarding WWVB signal strengths, it will be about 100 microvolts per meter or greater in Spokane.  I figure if a radio controlled clock can get the signal, so can our equipment?  But, like I say, I'm a newby at sferics.

I know that my own fluorescent lights kill my station.  But, the e-field antenna is out in the garage 5 feet away from the lights too.  So, perhaps the neighbor's lights....

I did an experiment yesterday where I put the E-field antenna and preamp out on my weather station mast and ran about 100' of quad shield RG6 back to the amp.  The data signal from the weather station (a 1-wire microlan) just killed the e-field signal.  Powering down the 1-wire system made it much better but....I want the weather station too!

So, I put the e-field antenna on the garden shed roof as far away as possible from the weather station mast.  And got more noise but not from the weather station data cable.  Still evidently an unusable site though......

More experimenting today......

I haven't seen any robotic lawnmowers in my neighborhood.  Glad of that.  Some electric fences nearby.  I've eliminated the one BIG source of RFI and that was my electronic dimmer switch and LED flood light.  Those things just howled.

I'm not ready to ask Jim Creek to turn down the power quite yet..... :grin:
Title: Re: Interference and Noise: wireless power transmission
Post by: CF20852 on April 10, 2015, 08:23:47 AM
In case you need something new to worry about, read this document on wireless power transmission, which includes mention of VLF frequencies:
http://www.itu.int/dms_pub/itu-r/opb/rep/R-REP-SM.2303-2014-PDF-E.pdf (http://www.itu.int/dms_pub/itu-r/opb/rep/R-REP-SM.2303-2014-PDF-E.pdf)

And this article that talks about wireless power transmission to electric buses at 20 kHz in Korea:
http://www.bbc.com/news/technology-23603751 (http://www.bbc.com/news/technology-23603751)
Title: A Wow Moment! The "Pesky Project"
Post by: Cutty Sark Sailor on April 14, 2015, 09:23:59 PM
  (http://sferics.us/bo1/Smileys/akyhne/yahoo.gif) Looks Good So Far
How to take a pesky from this:
(http://www.ourspecialnet.com/Weather/Pesky-Project/i-8NZ5wNd/0/L/pesky%20a%20before%20cr-L.jpg) (http://www.ourspecialnet.com/Weather/Pesky-Project/i-8NZ5wNd/A)

To This (Compare the images closely):
(http://www.ourspecialnet.com/Weather/Pesky-Project/i-bNnwshz/0/L/pesky%20b%20after%20cr-L.jpg) (http://www.ourspecialnet.com/Weather/Pesky-Project/i-bNnwshz/A)

... and still have signals like this:
(http://www.ourspecialnet.com/Weather/Pesky-Project/i-7P2czW4/0/L/pesky%20c%20stroke%20after%20cr-L.jpg) (http://www.ourspecialnet.com/Weather/Pesky-Project/i-7P2czW4/A)

Now to prototype another, and apply to A channel... #-o
and see how it goes for awhile...
http://sferics.us/bo1/index.php?topic=136.0
Follow it there, until it's ready for prime time...
After all, that's one of the purposes of the Region 3 Operator's Site!
 :twisted:
Title: Re: A Wow Moment! The "Pesky Project"
Post by: robo on April 16, 2015, 09:26:37 PM
and see how it goes for awhile...
http://sferics.us/bo1/index.php?topic=136.0
Follow it there, until it's ready for prime time...
After all, that's one of the purposes of the Region 3 Operator's Site!

Mike, why do you post links to a secret forum here?

Bye,
Robo :)
Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on April 17, 2015, 11:38:00 AM
When the innovation is proved out ,operationally, I'll bring it here, and to the BT forum also. Meantime, Region 3 operators can provide their input, or go ahead and try it, at the link posted.  There's no sense in bringing junk into a public forum, messing folks up, confusing them even, until something might possibly be viable and applicable.  The link is for Region 3 operator's convenience. That's why.

Now, proving it out with theory, is beyond me,... at this stage of life. I've forgotten too much... .But I'll say this, this thing appears to be kicking butt this morning with "Mark I" applied to both channels. Hopefully after some observational and operational time I'll present it as a done deal, works great for me in my situation, folks can have at it, and those who choose to figure out the whys and wherefores can do so. So far it's doing something I didn't quite expect, results-wise... figured it was just another waste of time...
Title: Re: Interference and Noise The Pesky Mark I
Post by: Cutty Sark Sailor on April 20, 2015, 07:29:05 AM
Ok... Here it is:
(http://www.ourspecialnet.com/Weather/Pesky-Project/i-zBvbMD3/0/L/Pesky%20Proto%2004152015-L.jpg) (http://www.ourspecialnet.com/Weather/Pesky-Project/i-zBvbMD3/A)
Yeah, I know, I know... probably a hundred reasons it shouldn't work better than a round over core shield. Don't care.

What I do care about, that for those couple of 'pesky' intermittent E components that a round close shield, of foil, copper, pipe, ribbon cable... whatever variation had no effect... this does. somebody else can figure it out.... and a bumble bee can't fly.

The idea appears similar to "trough' shields for ferrites.
Did find one specific reference to this idea, where the author appears to be using the same paradigm... attached 1990 article.

The History? 
I found an 50 year old 'shorthand' note I'd scribbled when ELINT / ECM tech in SEA, possibly relating to a communications jammer  or possibly a DF system.... from a discussion with a Hallicrafter's tech rep, I suspect.. 
...took a few minutes to decipher a couple of things, the rest is obscure, but ....
I wish I could reconstruct the conversation that elicited the 'cryptic' note, and the context of that conversation... I know that it likely had to do with a communications freq jammer, or probably our LF DF antenna. In the context of the war environment, we were constantly looking for calibration references, etc, and Hallicrafters was instrumental in both those systems, at the time,... so looking at the references I suspect we were brainstorming checkout and diagnosis for "off the cuff", quick reaction shop evaluation and or flightline troubleshooting, if you follow me.... The receiver/ transponder shop was enclosed in a Faraday Cage to keep out noise, but we needed to simulate airborne, as well as flightline, situations at times... that one rotary DF antenna was notorious for generating LF and VLF electrical noise into adjacent systems when the commutators began to fail... so we were probably looking at a "quick diagnosis" for noisy rotor.  One thing that is curious is the note explicitly states that " sides= c x 10 "  with some other faded and scribbled crap... and I do recall, somehow, that the c was referring to the core diameter of a ferrite rod.... I also interpret the scribblings to hint that this applied at certain frequencies, but there's no reference to which ones.... from the general context, I assumed we were discussing the bands between about 240 Hz (typical commutator noise pulses) up to about 2mHz. 

The other thing I'm wondering is if one of the scribblings might say that the "thickness of the shield material"  is important... can't prove that, but I suspect it strongly.  The Pesky Mark I  is just covered with copper foil.  Both antennas are now in "Mark I" shelds... and looking fine.  Prototype headed for the museum shelf.

So...  there you go... I'm minus 2 or three intermittent low level E component peskies on my H field. that have pestered me for a year or so.The theories, math etc are beyond this old tired brain. Have at 'em.

Mike


Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on April 25, 2015, 10:44:16 PM
Dang it.. I've got a blasted new noise source, appeared yesterday, intermittent.. playing heck with both E and H fields...
sigh... a never ending battle for truth, justice and the Blitzing Way.... sheesh.... maybe the damn source will smoke itself or blow up....
aaaarrrggghhhh!   explore it later, if it persists.... rats...
Title: Re: Interference and Noise
Post by: miraculon on April 26, 2015, 02:52:22 PM
I just had an "interesting" experience with my new garage door opener causing interference mode on the Blitzortung RED.

After getting the opener working right, I checked the Blitz cabinet just to check on things. To my dismay, RED was in serious interference mode. Checking the GUI confirmed that this was the case.

Interestingly, the old Green detector was happy as could be. Inspecting the waveforms, and temporarily turning off the E-Field, confirmed my suspicions that it was not magnetic field. The 1m 9T loops were not bothered.

Unplugging the new GDO, the interference mode ceased. I also tried disconnecting the pushbutton wiring connector, with no effect on the interference.

I was able to reduce gain and increase the threshold voltage and restore some semblance of functionality.

I took my "Natural Radio" VLF receiver and when the antenna was close to the "safety sensor" wires, there were some popping noises, that are probably edges from data transmissions to and from the sensors. My other RF sniffers, which use a coil didn't find anything. The VLF receiver has a whip antenna and is E-field.

Initially, I added snap-on ferrite cores near the GDO head, but after some back and forth with Sparkfinder (Wes) on the sferics.us forum, we concluded that the safety sensors were the transmitting culprits. (Thanks Wes, et al for your suggestions) I also placed ferrites at the sensors just in case.

The conclusion was that shielding of the wires was needed. I had some foil-backed insulation pieces that the former homeowner left over. I made a "shield/ground plane" by taping over the offending wires with copper tape.

The GDO head was grounded, so I ran a ground wire from it to the foil side of the insulation.

This fix was amazingly effective. I had reduced the gain to get the RED out of interference mode. With the shielding in place, I restored the gain I had previously. I even increased it beyond the earlier setting and it was still OK.

As has been pointed out to me, the location of the E-Field antennas in the rafters might not seem to be ideal. However, the 220V power lines feeding my house run directly over the garage and would place the antenna quite close to them. The location was my best compromise and worked well until I installed the new door opener.

(http://www.miraculon.net/DSCN1730.JPG)

.
.
.

Another view showing the antenna better. I am wondering if the shielding of the wires and the creating of a ground plane are both contributing. The offending wires are below the ground plane now, under the copper tape. The white wire is 110V power.

(http://www.miraculon.net/DSCN1731.JPG)

Greg H.



Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on May 01, 2015, 10:16:01 AM
 Received an interesting, very accurate, and astute PM from an observer earlier today... brought up a very valid observation... one I don't think we've ever spent much time on, but it could really be confusing.  He noted that the images describing "60Hz" noise were actually about "1000hz", and he was basing that (very true) observation on the times displayed.  And he was correct.... however:

The system actually won't detect 60Hz.... what we're seeing is harmonics, in image below about 3.6 -4.8 kHz....  but it is due to the mains box... along with the conversion and sampling rates what we sometimes see on the display is deceptive. The system does not really work like an "RF" or "Audio Frequency" amplifier,... most of the energy is contained, in this case, at 60Hz.. and that's out of the bandpass... the system shows energy during a certain time, at certain frequencies... and the higher '60HZ' harmonics have less energy... but they'll show a misrepresentation at times.   I guarantee those images are due to mains...  they were taken with the antennas right next to the power panel, as was this one a few moments ago.
(http://www.ourspecialnet.com/Weather/Pesky-Project/i-rqDdjkP/0/L/60hzartifact-L.jpg) (http://www.ourspecialnet.com/Weather/Pesky-Project/i-rqDdjkP/A)
Title: Re: Interference and Noise
Post by: andystorms on May 07, 2015, 08:58:52 PM
OK just wanted to know why a light bulb in my living room can cause interference,today I set my station up manually with settings 10.10.40 on both chanels.
was running great all day I even was at the top spot in the station list. Now I'm at work and dad's at home he switched the living room light on now it's caused my station to go into interference mode will stay that way now until I finish my night shift in another 4 hours.

Now how can I stop the interference from the light bulb.

Any help would be appreciated.

Thanks.
Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on May 08, 2015, 07:36:55 AM
At least you know the source  :twisted:  You don't say if it's LED, CFL, or even a standard on a dimmer. All three are notorious. If shielding antennas doesn't help, try different bulbs.  Maybe ferrites on the power cords... Get antennas as far away from source as possible. And if you're running BT in auto, your system will cycle in and out of interference and drive you crazy.  Find the trigger, gain point where the EMI doesn't trigger interference,.. You can access your controller from the internet if you set it up that way, and adjust from work.... lots of things you can do... but if Dad and the same Light is inseparable, and none of the others work work... it's called 'live with it'  #-o
Remember, this is a network... not about being "#1"...  :grin:
Title: Re: Interference and Noise
Post by: andystorms on May 08, 2015, 10:26:58 AM
Thank for your reply I'll change the bald tomorrow.
Its working good again now intill the light goes on.i'll put it into auto then.
Thanks.
Title: Re: Interference and Noise
Post by: andystorms on May 11, 2015, 11:15:05 AM
Just to let everyone know i solved my noise problem by changing the living room bulb to a led one the cfl i had caused noise interference led dosent so now i can keep my gains up on my lightning detector which gives me better detection all around and gives me better statistics.

Thank you all who helped.
Title: Re: Interference and Noise
Post by: miraculon on May 17, 2015, 12:53:44 PM
The "Auto Amplitude Filter" reallly works well.  I had a rather severe noise this morning, driving the old Green unit into continuous interference mode, and the RED was adapting like crazy trying to get rid of it. It had trouble dealing with the noise, being in interference mode most of the time.

Although I didn't capture a "signals" image, it was a repetitive pulse of well over 100mV amplitude. The pulse width was in the lows "10s" of -seconds. No idea on what it was, since none of my "sniffers" would pick it up. No effect on E-Field and since both RED and Green were affected, it was definitely H-Field.

I had to go to an extreme threshold on Green to get rid of the constant interference mode. Over 550mV, whereas the original "default" is at about 417mV. I typically run it at 350mV when there is no noise present, which is the normal case. My Green is specially modified to allow a variable threshold, although with the controller out in the garage, this is not as useful as it once was when the controller was at my desk at my old house.

On the RED, I was able to get the system out of interference mode, by activating the "Auto Amplitude Filter". This is the first time I was able to make an A-B-A test of the Auto Amplitude Filter. The RED system definitely entered and left interference mode when I toggled Auto Amplitude Filter. It really worked for this case of noise, which as previously described was repetitive in amplitude and frequency (at least the rep rate put it at the same point on the signals display every time).

Previously, all other activations of Auto Amplitude Filter were kind of a blind guess, this time I could see the positive action of the filter.

Greg H.

Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on May 18, 2015, 07:50:03 AM
If memory serves, that situation was one of the specific cases the AA filter was added... Most folks don't need it, and will actually perform better without it.  Similar paradigm on auto adapt to noise.  I also experienced a strange interference signal for about 8 days, which kept H field in interference unless I ran manual at about 8*1 or so.  I also could not locate it with any of my techniques... similar to yours.. pulsating between roughly 80-90 KHZ with subs around 8-24 KHZ, and a few >160... It was external to the residence, and frustrated me no end.  Weaker presence on the E-Field C channel (wider bw on C)  Today and yesterday I do not see the Pulse trains, but there is some indications of a VLF carrier... but my environment is tough anyway, so we'll have to see...
The filters had no noticeable effect, and I was on the verge of reviewing my ancient theory and parts boxes to construct a specific 80-90 notch... at the sacrifice of other stuff... this thing was putting H field out of operation for me.  Like you, I could NOT detect it other than with the receiver, although I could get a directional line of sorts...  I do have a suspicion of a possible source, but it won't be easy to prove, or mediate...
Title: Re: Interference and Noise
Post by: miraculon on May 18, 2015, 08:26:07 AM
My lack of success with the various sniffers that I have built or bought (and the $$$) is frustrating sometimes.  ](*,)
I think that I have decided what to do with my "Green" amp/antenna once "Green" support on BlitzO goes dark later. (this year, next? who knows?)

I will add a battery and a couple of VU meters to it and create a portable sniffer out of it. There is even a headphone jack already on it. I am sure that walking around with the box while wearing headphones will really impress the neighbors. Here comes the men in the white coats!

At least I know it will work!

Greg H.
Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on May 23, 2015, 10:41:40 AM
While communicating with some operators, I developed a sense that some of us might be
confused when we speak of "interference" and "interference".... :D
We might be using "interference" as 'a disturber or noise that degrades communication or data, or a system's operation'.
But we might also simply be referring to "a system going into 'interference' ".

System RED (and BLUE will likely operate in a similar manner) will go into one of two types of "Interference Modes" from time to time.  "Burst" or "Normal"
The System is designed this way, generally,
1. Because nearby active cells produce so many signals, so rapidly, that they cannot normally be recognized separately... and matter of fact, one "paradigm" of the developers might be phrased as "detected signals <30km are generally useless to the network"  with the current design, anyway.
So when you go interference because of nearby storms.... accept it, let 'er ride, and let the network do its net work.  :D
2. Unless you have a perfect location, sporadic 'disturbers' such as an arcing power line, may produce conditional interference that swamps the controller similar to nearby cells, such are useless anyway.  But they're sporadic, and when they cease, you'll come out of interference.
3. Repeating, identical, signals that might be caused by someone standing nearby with walkie-talkie, burst of repeating  power line noise... weird stuff.

Now, while Interference Modes can be triggered by non-lightning signals,  it is based on the "number of signals sent" within certain time frames.
Except for the limited 'repetition and recurring' algorithms for "Burst Mode", it has no recognition of "types of signals" and doesn't care.
Interference mode can be activated due to signals on all channels, or one single channel, or a combination if you're running 5 channels including both H and E field.

It also is one 'controller parameter' that is monitored over time and varied by the server/controller! 
In other words, the server/controller can lower or raise those limits depending on what it sees from your station! 
You only have "indirect control' of this response: your operating mode, gains and thresholds, etc.
The 'basic' purpose is to avoid sending "too many signals" or "EM noise pulses" from your station.

These "interference parameters" operate no matter what mode you're in -Auto or Manual: 

If you look at your 'status' page when you access your controller web interface, down under "other parameters', you see something like this:
Interference Mode
   Burst        When > 80sig/s in 3s average. Disable when 50% below threshold
   Normal     When > 70sig/s in 60s average. Disable when 30% below threshold

...and if too many signals are actually sent under certain conditions,
that will 'back that down' to, for e.g. 30sig and 15sigs.... until
you can come out of interference, and the limits will rise again after some period of time.

So if over "some period of time" you've averaged over 70sigs/minute, you'll go into "Normal" interference, and stay there until it drops below 70sigs average.... which can be a long time... especially if the /controller has lowered the max limit temporarily for your controller to 15...! And if you are in Auto mode it could take even longer under certain conditions, as the controller may continuously cycle on and off and in and out of the mode.

For Burst mode... (short periods of repeating signals) it'll come out of interference much quicker.. a few seconds). It can be longer, again, if your limits have been temporarily lowered...

Remembering that you have only indirect control over 'Interference Mode" ... each channel's 'gain and threshold' settings.
If you're in "Automatic" mode, you have no access to your gains and threshold settings. Unless you desire to wait until the sources vanish on their own, you'll have to return to "Manual" mode, and reapply gain/thresholds settings under each specific amp, (the actual gains /thresholds have been set by "Auto", and they are NOT visible under the AMP settings... that shows you your settings so you must hit apply to reset the "Auto" parameter.
It follows, then, that if H channel A is the one causing the interference, you could back down channel A to 'just under noise trigger level, it will now come out of interference, and channel B  continues its merry way, and A now is of some use also.
You can take it from here.

(This is duplicated at http://sferics.us/bo1/index.php?topic=130.0 for cross searching )
Title: Re: Interference and Noise
Post by: dfroula on May 23, 2015, 11:29:33 AM
Nice post and a very good explanation of an important distinction!

Thanks, Mike. I was explaining this to another member privately a few days ago. You summarized it far better than I.

Best regards,

Don F.
WD9DMP
Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on June 14, 2015, 10:18:04 AM
Stumbled across this, which on a quick view, appears to use the "Pesky" hypothesis....
http://www.hindawi.com/journals/ijap/2013/163905/ (http://www.hindawi.com/journals/ijap/2013/163905/)
of all things, breast cancer!
Need study it a bit more... but:(http://www.ourspecialnet.com/Weather/Pesky-Project/i-TPZ38rZ/0/L/163905_fig_002-L.jpg) (http://www.ourspecialnet.com/Weather/Pesky-Project/i-TPZ38rZ/A)
Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on December 01, 2016, 04:55:14 PM
Couple of thoughts:

First...Last year, etc... we tried to use the FFT display for localizing Freq of noise, and found that there was about a 20% error in freq.  I checked a few minutes ago, and it looks like that has been more or less resolved... looks like any error is maybe a % or 2 'high'... checked on both RED and Blue, and now looks like this at 100 kHz -- at antennas:
Click for large image... 100 kHz at antennas, Red & Blue
(https://photos.smugmug.com/Weather/Blitzortung-Blue/i-d4x3xhL/0/M/FFT%20100%20kHz%20R-B%20H%20A-M.jpg) (http://www.ourspecialnet.com/Weather/Blitzortung-Blue/i-d4x3xhL/A)

Note: Americas Region (Region 3) RED and BLUE operators can view their signals at http://sferics.us/  at "Live Station Signals"  or direct access at http://sferics.us/BoStaSig/   NOTE you must be registered. Registration only available for Blitzortung Operators with valid station, id, region, etc....
If your Americas region (3) station isn't on the station list, let me know... or if you need to change something... Email me.

Second
I don't think the problem is too severe here in Region 3, but I'm convinced a lot of new operators are using inadequate power supplies, causing some of their headaches.  The way BLUE is designed, often grounding in some locations is causing more issues.  I'm also convinced many are not spending enough effort to track noise sources... too bad. Not for the faint of heart.

Third ANYBODY having an issue periodically with poor page loading on attempting access WEB controller?
Title: Re: Interference and Noise
Post by: miraculon on December 02, 2016, 08:26:58 AM
Quote
Third ANYBODY having an issue periodically with poor page loading on attempting access WEB controller?

Yes! This has been happening on the RED, but not the Blue. I have been running FW 8.3b2 (on both with their respective "colors")

I either get a text-looking white screen with just headers or something. The display is blinking the "NET" icon and when I select with the "user" button, it complains about checking the network connection. The RED is on the same switch and WiFi Client as the Blue, and the connection is solid. A reboot clears it up, but it recurs after about a week.

Is this an artifact of the http debug messages that Tobi added? I have been contemplating reverting the RED to the last stable release. I have to go out to the garage to reboot the unit. Interestingly, the data still appears to be getting through and is current on the List Of Stations.

I wish that there was an SSH option to remotely reboot without the GUI (or the trek to the garage).

Greg H.
Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on December 02, 2016, 11:11:04 AM
Quote
Third ANYBODY having an issue periodically with poor page loading on attempting access WEB controller?

Yes! This has been happening on the RED, but not the Blue. I have been running FW 8.3b2 (on both with their respective "colors")

I either get a text-looking white screen with just headers or something. The display is blinking the "NET" icon and when I select with the "user" button, it complains about checking the network connection. The RED is on the same switch and WiFi Client as the Blue, and the connection is solid. A reboot clears it up, but it recurs after about a week.
Quote
Is this an artifact of the http debug messages that Tobi added?

Greg H.

I don't think so.  Here's what I'm speculating ... There's a whole lot of JUNK crap coming into the BT servers from a lot of crappy new BLUE installs... that's obvious.  Thank goodness it doesn't seem to be centered in our region,.  Also, I think they're doing some server work to help combat this. Also there have been some network crap into and in Europe.
Now, the Server wants to 'talk to' the controller quite often.
I think what's happening is the server and local controller hare having periodic issues communicating with each other... when the controller is in 'receive / adapt" mode, trying to get packets from server, and we also try to connect, ... that's when I think a lot of this is happening.
thoughts?
Title: Re: Interference and Noise
Post by: miraculon on December 02, 2016, 12:21:17 PM
Quote
thoughts?

So it sounds like it would be across the various FW versions and reverting isn't going to do much good, if your theory is correct.

Hmm.. I hope that they come up with a fix. DDoS via Download? Is that what is going on?

Greg H.
Title: Re: Interference and Noise
Post by: Cutty Sark Sailor on December 02, 2016, 12:32:10 PM
I've had the issue before, intermittently, on both Colors, with Various firmware... Jay also had an issue last couple of days... similar.
Mine was so bad this summer while a lot networking to Europe issues in LEVEL 3s, that I (NOW- don't ask me to explain this) switched from LAN accessing to WAN accessing, and it made a dramatic speed improvement as well as more reliable connection. I've an inquiry in to DEVs, waiting on their thoughts...