Topic: New station (1006) and many problems with interferences & noise

[Knickohr]

Hi togehter,

I'm a newcomer TOA 

Build up my station the last days and I'm happy to share my "strokes" with the Blitzortung-network, but most of the time I share my noise and interferences with the network 

The interferences coming from the electric power grid. I switched off all electrical equipment at the main fuse and the noise is always persistent. It's a kind of magnetic noise, because my E-field antennas are not effected.

Do you have an idea what it is ?  It's around 7 to 8kHz.

Thomas

[JonathanW]

If it's affecting both H-field channels simultaneously, regardless of how you orient the antenna, it seems to me it would be internal to the system/coming in on the system power supply.  Is the H-field amp connected with a shielded cable to the controller?

But I'll wait for those with more experience to discuss...

[Cutty Sark Sailor]

First, connect only your H field to amp one.... then, later, connect E field to amp 2.... that gets our colors all in line, for one thing. Red Amp 1 Ch A, Green Amp 1 Ch 2, etc... .
#2 Your gains are extremely high on amp 1.... we may need to look at that later.
 Your information says also that you are running some HUGE antennas
◾Antenna 1+2+3: Electric field, length=2000mm
◾Antenna 4+5: Ferrite rod, length=400mm, diameter=16mm
Wow,... are those correct???

Let's deal with one issue at a time... find the H field noise...
Power off the system by removing the mini plug from the controller.
Disconnect both amps.
Connect the H field (Amp 1) to the Amp 1 Rj45 connector (next to the GPS IC...)
leave E field unconnected...
Power controller back up. 
Go from there. Single mode operation.

Don't forget to 'apply' each group below individually as you change them.
if you do forget, they won't change.
You'll get a 'warning' box at the top, when you're through applying each,
make sure your save the changes you've made... confusion will exist as
you modify later if you don't have some starting point. You'll 'apply'
different settings to test and temporarily change settings. They'll not be
saved, and will be lost on 'reset' or reboot and restored to what you've established
as your default. When you establish a norm, then you can 'save'...
Control settings...
Manual mode...
uncheck both "auto adapt" and "auto amplitude" boxes
potentiometer off
gains Amp 1  A and B both 10x10
thresholds 120
force all channels on ... unchecked
alternate channel mapping unchecked.

Now, if you haven't, go explore http://www.wxforum.net/index.php?topic=20439.0 ...

one good thing, you've apparently determined the freq of the interference... hold that thought...

Let me mention again, that I strongly suggest any 'newbies' who are going dual amps first get acquainted with their H field environment, before adding the E field amps to the system.
This signal that Thomas is wrestling with may be from anywhere, and if, for example, it's his power supply, it may effect E field in the long run...

Mike

[Knickohr]

n0ym, Mike !

Yes, the signal is orientated. I put the H-field antennas in the direction, who is for both antennas the same

And yes, the interferences coming out of the house, any house, my house, the house of my neighbors.

I can't use the station inside the house, too much of these interferences. I use it in my private observatory. Is powered by a photovoltaik charged battery, so no power converter, no power supply form the electric grid.

First, connect only your H field to amp one.... then, later, connect E field to amp 2.... that gets our colors all in line, for one thing. Red Amp 1 Ch A, Green Amp 1 Ch 2, etc... .

Does this make sense on what amp which antenna is connected ?

Antenna 1+2+3: Electric field, length=2000mm
Antenna 4+5: Ferrite rod, length=400mm, diameter=16mm
Wow,... are those correct???

Yes, correct. I'm using big antennas 
(E-field is a 2000mm copper tube, 12mm diameter)

Let's deal with one issue at a time... find the H field noise...
Power off the system by removing the mini plug from the controller.
Disconnect both amps.
Connect the H field (Amp 1) to the Amp 1 Rj45 connector (next to the GPS IC...)
leave E field unconnected...
Power controller back up.

Done, the noise is still there 

ontrol settings...
Manual mode...
uncheck both "auto adapt" and "auto amplitude" boxes
potentiometer off
gains Amp 1  A and B both 10x10
thresholds 120
force all channels on ... unchecked
alternate channel mapping unchecked.

Done !  10x10 is too much for my big antennas, set it to 4x2.
Noise still there 

This signal that Thomas is wrestling with may be from anywhere, and if, for example, it's his power supply, it may effect E field in the long run...

I don't understand this. My E-Field antenna is not affected, it works perfect. Yes, with very high gain, but it detects strokes 2500km away. And Mike, it's not the power supply. The station is powered from a solar-battery with an linear voltage regulator down to 5.0V.

Thomas

[Cutty Sark Sailor]

Ok, Good Job!
I think consistency of channel color is important, regardless of any technical issues... and sticking with H on 1 and E on 2 keeps some kind of standard going.
Also remember that the developers want the efield used for shorter distances, under 500km... Now, you may have such issues with H field that E field may be the only way to go for you, but 2500 Km ( about 1500-1600 miles) is a great range for H fields.

Are you really using  400mm x 16 mm ferrite cores?
if so, then that may be part of the reason... about as big as we go over here is 300 x 7.5, One or two 350mm x 7.5 mm systems...
and a 250mm x 7.5 will hit >4000km if conditions are right.
Although the M component of the H field normally won't affect an E field probe, the opposite can cause issues... Strong E field noise can be induced in the ferrite loops, which is why some have shielded the ferrites. Mine are unshielded. Typical shielding will have no effect on any near field H interference.

I had a similar issue to you on H field... I managed to find one sweet spot in the garage, one area about 2 meters square, 1 1/2 meters above floor, that brought my M interference down to 40-60mv, and is totally operable on H field.  Also, does not bother E field.

I don't know what your noise level is, but you might try bringing the gain on down on H field, say as low as 1x1, and check positioning... see if you can get it in a range of 40-60 mv noise... and experiment. 
I assume you're using shielded CAT5 cable, have very short leads form the ferrites to the antenna block, and have grounded your controller only at the ground lugs?

I'll leave it to others with experience with battery type supplies, such as solar power... I can imagine issues with such connections, especially wiring, but have no experience.

[Cutty Sark Sailor]

Thinking out loud... using the photovoltaic battery... in effect could you an isolated ground, as would any power supply... Controller should be connected to good cold water ground, with the ground block on the controller, and passes that ground to the h field antenna loops through the cat 5 cable. No other grounds should be attached.

[Knickohr]

OK Mike,

I will change amp channels for H and E.

Yes, 400/16 ferrite cores  Really big 

I tested a 200/15 H-field antenna too. The noise is lower, but still persistent 

For testing I had shielded the ferrite, but nothing happens, except the sensitivity is going down, so I have unshielded them back.

H-field noise is about 140mV, E-field at 70mV.

Yes, I'm using double shielded Cat6e network cables. Grounding is on one point at the E-Field preamp with an extra made earth rods, 1m deep into the ground. I tested grounding on the controller, still the same 

The next thing I will do is to search for a Mu-metal housing for the preamps.

Thomas

[Cutty Sark Sailor]

Don't ground the E preamp! Only ground in the circuits should be the controller lug!  Ground loops cause EMI!
My controller is actually grounded ONLY through the shield of the cable TV coax that enters the house. Works best in my situation. Can almost always depend on them to have good earths. Cannot depend always on ground rods, utilities, or cold water pipe!

[Cutty Sark Sailor]

Oh... anybody nearby got an electronic dog/pet fence?????? 8Khz.... I've been brain dead... duh

[Knickohr]

I don't know. I always think, this interferences come from the power grid. If I put my H-field antennas near a power plug then the noise increased rapidly.

I checked my last strokes. Looks like the E is better for distances up to 500km and the H better for > 500km. My nearest stroke is at 0.0km and the far away at 3000km.

OK, next thing to do, ground station at the controller lug 

But how do I protect my E-field antenna against direct strokes ?

Thomas

[Knickohr]

Running my station since 2 days with the FW 7.0b5.

Looks good, much less problems with the noise. Running in "half-manual mode" (manual mode with noise adaption and auto ampl. filter).

Keeping the noise at 40mV will be a good value !

Still searching the origin of the interferences 

Thomas

[Knickohr]

Switching back to fully manual mode 

The station is more sensitive with the manual setting and give much more efficiency.

What's the better settings ?

- High gains with high thresholds
- Low gains with low thresholds ?

What does the 2 white striped lines (about 100mV) in the Live Signals tab show ?

Are there any documentation/manual/papers how to find the optimal settings available ?

Thomas

[Knickohr]

One problem solved !

The lug from the preamp was broken :



I search nearly one hour to find this 



After resoldering a new one, the preamp works fine. I still uses high gains with high thresholds, but now only with an 350mm V2A stick on the top of the old antenna, about 3m from ground :



Now, waiting for some nice strokes 

Thomas

[JonathanW]

Good job!  Nice troubleshooting.  Broken parts can be tough to track down.

[Knickohr]

There it coming :  1000 strokes per hour 

And the storms are more then 500km away. E works good, but still problems with the interferences at the H 

Thomas

[Knickohr]

So !

I'm totally frustrated 

Have thrown away the H-field antennas with the amp and now, the station works very well. I'm going up on the top-list to rank 50 and above 

So, probably it's not possible to run a H-field antenna in my neighborhood with this magnetic interferences. Have written an eMail to my local power supply distributer, but only receive some nasty eMail from them. They say, I should install an central interference filter in my power line. But what effect has this, if the interferences coming from the powergrid, transmitted through the air ?

My station is now running only with the E-field antenna !

Thomas

[JonathanW]

So !

I'm totally frustrated 

Have thrown away the H-field antennas with the amp and now, the station works very well. I'm going up on the top-list to rank 50 and above 

So, probably it's not possible to run a H-field antenna in my neighborhood with this magnetic interferences. Have written an eMail to my local power supply distributer, but only receive some nasty eMail from them. They say, I should install an central interference filter in my power line. But what effect has this, if the interferences coming from the powergrid, transmitted through the air ?

My station is now running only with the E-field antenna !

Thomas

I hope you didn't mean you literally threw them away   I wonder if shielding might help, or a Gaussmeter to find low magnetic field areas for siting?

[Knickohr]

Shielding doesn't help 

I tried it on one antenna and after all I removed it, it decreases the sensitivity.

Are anybody interested in 2 400/16 ferrite-rods, a 200/15 rod and 2 system RED amps ?

Thomas

[Knickohr]

Reaching the Top Ten only in a few hours 

Only with E-field 

Thomas

[JonathanW]

Switching back to fully manual mode 

The station is more sensitive with the manual setting and give much more efficiency.

What's the better settings ?

- High gains with high thresholds
- Low gains with low thresholds ?

What does the 2 white striped lines (about 100mV) in the Live Signals tab show ?

Are there any documentation/manual/papers how to find the optimal settings available ?

Thomas

You asked a couple of questions above...First, as I understand it, there isn't a whole lot of difference between the two choices (high/low gains/thresholds).  BUT, a couple of things to keep in mind:

1) System noise floor (higher gain, primarily in the first stage, should give you higher S/N ratios)
2) The possibility of overflow/ADC saturation with signals that are too high

Because of these two factors, from what I recall, the developers recommended thresholds of around 100 to 120 mV.  However, note that automatic control of gains/threshold will give you combinations that are basically all over the place (as long as they don't exceed the "relative gain" of your manual settings).

As for the horizontal lines, there are two "benchmark" lines corresponding to 0.5 V and 1.0 V.  The other lines correspond to threshold levels.

[Knickohr]

I'm wondering, how some stations can handle more than 20,000 signals/h 

If I'm going up to 20,000, my station is getting into interference mode 

Just in time, there is a storm coming, more than 25,000 signals -> interference mode - setting down the amp by factor 2. But there are some station which working well with 35,000 and more signals/h 

Thomas