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Total 144 documents matching your query.

21. Re: [RFI] Does anyone recognize this RFI? (score: 1)
Author: K9MA <k9ma@sdellington.us>
Date: Wed, 15 Apr 2020 13:52:35 -0500
I may have misinterpreted the frequency scale, as I thought it was RF. It appears it is audio, Hz, not kHz, in which case I agree, it doesn't look like a switcher, but something modulated at 55 Hz. 7
/archives//html/RFI/2020-04/msg00031.html (11,690 bytes)

22. [RFI] Power Line Noise (score: 1)
Author: K9MA <k9ma@sdellington.us>
Date: Thu, 16 Apr 2020 16:32:18 -0500
I think I just learned something interesting. I'm in the city, surrounded by 14 kV overhead lines. I went out today to track down a noise source, which on the HF bands appears to be coming from the e
/archives//html/RFI/2020-04/msg00032.html (8,043 bytes)

23. Re: [RFI] Power Line Noise (score: 1)
Author: K9MA <k9ma@sdellington.us>
Date: Thu, 16 Apr 2020 17:16:13 -0500
Scott, I give you even money odds that you found ANOTHER noise source on VHF, and not the one that was affecting you on HF (unless you already got it fixed, and that was it, in which case I lose hi h
/archives//html/RFI/2020-04/msg00035.html (8,834 bytes)

24. Re: [RFI] Power Line Noise (score: 1)
Author: K9MA <k9ma@sdellington.us>
Date: Thu, 16 Apr 2020 17:55:27 -0500
That's basically right.  A horizontal antenna in free space has no vertically polarized component at all in the plane of the elements. However, slightly above or below that plane, there is a vertical
/archives//html/RFI/2020-04/msg00038.html (10,083 bytes)

25. Re: [RFI] Power Line Noise (score: 1)
Author: K9MA <k9ma@sdellington.us>
Date: Thu, 16 Apr 2020 22:50:32 -0500
In many cases, I think the current causing noise to radiate is flowing in only one of the lines. For example, if a lightning arrestor were arcing (very common), the current flows primarily in the one
/archives//html/RFI/2020-04/msg00041.html (12,423 bytes)

26. Re: [RFI] Power Line Noise (score: 1)
Author: K9MA <k9ma@sdellington.us>
Date: Fri, 17 Apr 2020 11:04:17 -0500
I agree entirely. I do indeed find many sources which are NOT causing the problem. I identify the correct ones by simultaneously listening to the HF audio (relayed by phone) from the home station and
/archives//html/RFI/2020-04/msg00052.html (10,544 bytes)

27. Re: [RFI] Power Line Noise (score: 1)
Author: K9MA <k9ma@sdellington.us>
Date: Fri, 17 Apr 2020 11:45:00 -0500
The 1/6 wavelength is just a rough rule of thumb. For a yagi with a 24 foot boom, the calculator below says the far field starts at 15 feet. 1/6 wavelength is 11 feet. Both are much smaller than the
/archives//html/RFI/2020-04/msg00053.html (9,683 bytes)

28. Re: [RFI] Power Line Noise (score: 1)
Author: K9MA <k9ma@sdellington.us>
Date: Fri, 17 Apr 2020 14:54:50 -0500
Thanks for the explanation, Ed! 73, Scott K9MA On 4/17/2020 14:06, Hare, Ed W1RFI wrote: There are actually at least two different "near field" regions.  The first is the reactive near-field region,
/archives//html/RFI/2020-04/msg00056.html (15,256 bytes)

29. Re: [RFI] New Astron Switching PS RFI? (score: 1)
Author: K9MA <k9ma@sdellington.us>
Date: Mon, 18 May 2020 15:46:24 -0500
I've been using a Samlex SEC-1235M for years. I've never detected any RFI from it. Linear supplies, while they generate no RFI, have a particularly nasty, and common, failure mode. When the series pa
/archives//html/RFI/2020-05/msg00061.html (10,612 bytes)

30. Re: [RFI] Samsung oven RFI update number II (score: 1)
Author: K9MA <k9ma@sdellington.us>
Date: Sat, 23 May 2020 18:00:36 -0500
FWIW, we have an LG stove, refrigerator, and washer, and none is sensitive to RF nor radiates any. The tower is about 25 feet from the house, and it is shunt fed on 80 and 160. I have amplifiers. 73,
/archives//html/RFI/2020-05/msg00083.html (13,604 bytes)

31. Re: [RFI] Noise centered around 20 meters (score: 1)
Author: K9MA <k9ma@sdellington.us>
Date: Sat, 23 May 2020 21:31:24 -0500
I was very lucky a couple weeks ago when I was trying to track down some line noise. At one point, all indications were it was coming from a particular house. A walked all over the place with a VHF y
/archives//html/RFI/2020-05/msg00099.html (17,978 bytes)

32. Re: [RFI] Noise centered around 20 meters (score: 1)
Author: K9MA <k9ma@sdellington.us>
Date: Sat, 23 May 2020 22:58:55 -0500
That was the other baffling thing about this case: it had all the characteristics of power line noise, yet it appeared to be coming from a house. The spectrum was very broad and flat, unlike switchin
/archives//html/RFI/2020-05/msg00101.html (12,724 bytes)

33. Re: [RFI] Noise centered around 20 meters (score: 1)
Author: K9MA <k9ma@sdellington.us>
Date: Sun, 24 May 2020 13:45:27 -0500
It doesnt have to be something that serious: two pieces of poorly bonded hardware anywhere near a high voltage line will do it, especially if its within a few hundred meters of your antenna. They don
/archives//html/RFI/2020-05/msg00105.html (9,858 bytes)

34. Re: [RFI] Lightning Arrester RFI temperature related. (score: 1)
Author: K9MA <k9ma@sdellington.us>
Date: Sun, 24 May 2020 21:32:29 -0500
I had one that was only active when it was below +10 F. Getting my YL to take the video when I pointed the ultrasonic tracker at it was very expensive. 73, Scott K9MA On 5/24/2020 20:03, Don Kirk wro
/archives//html/RFI/2020-05/msg00107.html (9,278 bytes)

35. Re: [RFI] RV converter noise (score: 1)
Author: K9MA <k9ma@sdellington.us>
Date: Tue, 26 May 2020 18:32:57 -0500
Converter in the RV world is either a 120 VAC to 12 V power supply or a battery charger. Of course, they can produce the same kind of RFI as an inverter. 73, Scott K9MA -- Scott Ellington -- via iPad
/archives//html/RFI/2020-05/msg00114.html (8,108 bytes)

36. Re: [RFI] RV converter noise (score: 1)
Author: K9MA <k9ma@sdellington.us>
Date: Thu, 28 May 2020 15:46:30 -0500
Samlex seems to make good products. 73, Scott K9MA I use a Samlex SEC-1250UL converter after the original POS Winnebago installed let the smoke out. I have never heard noise/birdies on HF from it whe
/archives//html/RFI/2020-05/msg00123.html (8,823 bytes)

37. [RFI] Line Noise Fixed! (score: 1)
Author: K9MA <k9ma@sdellington.us>
Date: Mon, 22 Jun 2020 22:53:23 -0500
For many months, I've been plagued by line noise, often 25 dB above my "normal" urban noise level. I tracked it down to a 60+ year old power pole about a quarter mile (350 m) from my QTH. I tracked i
/archives//html/RFI/2020-06/msg00021.html (10,957 bytes)

38. Re: [RFI] Line Noise Fixed! (score: 1)
Author: K9MA <k9ma@sdellington.us>
Date: Tue, 23 Jun 2020 10:54:40 -0500
Hi Dave, That's a nice touch, using your phone to monitor the SDR spectrum. One of the defining characteristics of line noise is that it's very broadband, unlike switching supplies, etc. There are al
/archives//html/RFI/2020-06/msg00025.html (12,607 bytes)

39. Re: [RFI] 2 MW Solar Farm (score: 1)
Author: K9MA <k9ma@sdellington.us>
Date: Mon, 21 Sep 2020 22:42:36 -0500
Hopefully not as bad as the 2.3 MS Siemens wind turbines in New Zealand. ZL6QH had to abandon a huge antenna farm because of RFI. Their noise floor went up 50 dB on 80, and only a few of the planned
/archives//html/RFI/2020-09/msg00087.html (8,885 bytes)

40. Re: [RFI] Question Regarding Variations In Solar Panel RFI? (score: 1)
Author: K9MA <k9ma@sdellington.us>
Date: Mon, 28 Sep 2020 13:52:21 -0500
I wouldn't say magic, just complicated. 73, Scott K9MA -- Scott K9MA k9ma@sdellington.us _______________________________________________ RFI mailing list RFI@contesting.com http://lists.contesting.co
/archives//html/RFI/2020-09/msg00173.html (9,079 bytes)

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