Author Topic: Interference and Noise  (Read 104721 times)

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Offline Phil23

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Re: Interference and Noise
« Reply #250 on: September 14, 2019, 06:46:13 PM »
Considering moving my station to the rear of the property, about a 20m displacement, but that will not change it's location much in relation to an extension lead that runs on the other side of the yard to get power & data to the other shed via Ethernet Over Power adaptors.

I'm Station 1928 by the way.

Station has now been in it's new location for a bit over a week & it's a huge improvement.
Auto Settings are pushing the gains way higher & I'm seeing strokes at a much greater distance.

Efficiency gets up to 58% at times, but not sure how to interpret that number yet.

Now detecting out into the 5000km range again.

At this stage just looking at the gains set by Auto mode with the thought to try Manual once I have a better understanding of what is more appropriate.


Offline DaleReid

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Re: Interference and Noise
« Reply #251 on: September 15, 2019, 08:33:15 AM »
Thanks for the link to the Solar RF QST article.
I am very interested in this, having put in a solar system to provide hot air to my home for over 35 years, since the desired electrical panels were far too expensive to even consider when we did the project.

One item in the article raised some concern for me.  I have a lot of noise on some RM Young wind monitors feeding a variety of stations, and really have exhausted my limited ability to track down where that is coming from.  I read along the article when suddenly I went through the statement that switching inverters or power supplies were a source for noise, and relatively broadband it sounded like.

With more sensors needing power that my stations can't provide, I've been using little wall warts to send power to them (such as capactive rain gauge, Vaisala WXT sensors and other's.  I've usually bought switching supplies since I was under the impression that they were less likely to be noisy, at least on the DC supply side, and perhaps more efficient with long term use.  I also can scatter them to wherever the station I'm working with that needs external power rather than one big whomping source such as a lead-acid or gel cell battery that feeds all the required needs.

I also have a couple of heated rain gauges that need a bit more oomph and have used a couple of laptop powersupplies/chargers that were left over when the laptop got replaced and  were basically junk.  they provided 19 to 24 volts and a good amount of current.

Now I'm wondering if those are a source of interference that not only could affect my stations, but also contribute to the noise level for my RED and BLUE Blitz stations.  Along with this concern, I also realize the power runs up long straight (but shielded) cables to the sensors and heaters, the perfect radiator.

Any thoughts on switching power supplies?

Offline miraculon

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Re: Interference and Noise
« Reply #252 on: September 15, 2019, 01:12:40 PM »

Any thoughts on switching power supplies?

There can be well designed SMPS and bad junk out there. I haven't had a problem that I specifically linked to a wall-wart but it is definitely possible. I suspect some combination of being cost driven and ignorance of design for EMC rules would be the culprit in the noisy cases.

Also, I have had a lot of noise problems with LED bulbs with VHF, notably NOAA Wx radio. Some of those are really bad, and it is the built-in switching regulator that is the culprit (not the LEDs themselves).

Greg H.


Blitzortung Stations #706 and #1682
CWOP: CW4114 and KE8DAF-13
Amateur Radio Callsign: KE8DAF

Offline noctilucent

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Re: Interference and Noise
« Reply #253 on: March 04, 2022, 12:23:15 AM »
'...when you have eliminated all which is impossible,
then whatever remains, however improbable, must be the truth.' S. Holmes  :-({|=
"It must be aliens, what else could it be?" - Giorgio A. Tsoukalos.
« Last Edit: March 04, 2022, 12:27:40 AM by noctilucent »

Offline Phil23

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Re: Interference and Noise
« Reply #254 on: March 14, 2024, 05:08:28 AM »
Any Ideas what these two spike are likely to be?

They appear almost constantly on Channel 1A;; Mobius Loop Antenna, currently sitting at:-
10 * 10 * 40 = 4000 113 / -40 mV 53 mVpp.

Think from my Calcs the peaks @ 60uS PP equate to 16.666KHz.

The Antenna's are on the rear of a 15x7m ColorBond shed.
There's a few 12V Smart Chargers in there; two maintaining Batteries in a Boat & other Vehicle.
Couple of others, powered, but not connected.

Network Switch running data to the next Shed & POE up to a Wifi point at the opposite Gable.
Antenna's & Wifi AP both sit at the Highest points on the Gable, but at Opposite ends, so separated by 12.5m.
Another internal Wifi AP with 2.4G only, it's inside the shed, but at the same opposite end.

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