[ADXA] noise issue - take 2

[w5znjoel at gmail.com]

Jussi,

Go back and look at the technical report I sent to Entergy regarding power line noise that I forwarded to you. Look at the RF waveform on the K4 Panadapter and you can see the difference in the normal spectrum and when line noise was occurring. That is what power line noise will look like on the RF spectrum panadapter.

I have a similar noise source as you are seeing to my east and it is coming from a house over 1/4 mile away down on the highway. That is why I ask how close are your neighbors. The noise is ONLY on 160 meters and not on any other band but it is 20 dB stronger than the normal noise floor in other directions. I'm not exactly sure of the source and don't plan to go snooping around the two houses I suspect it is originating from. My 160 meter RX arrays are very sharp and I see it on with multiple arrays and it doesn't bother NE toward EU or directions other than east.

73 Joel W5ZN

-----Original Message-----
From: Richard Roderick <k5ur at aol.com> 
Sent: Monday, March 23, 2026 4:45 PM
To: w5znjoel at gmail.com
Cc: Jussi Eloranta <eloranta at aa6kj.hopto.org>; ADXA <adxa at mailman.qth.net>
Subject: Re: [ADXA] noise issue - take 2

Agree with Joel!

Hey, any glow lamps around there? Some of my worst QRN was from glow lamps down a road where you don’t want to be fixing a flat tire at night. 😳

73,
VP5/K5UR

Sent from my iPhone

> On Mar 23, 2026, at 5:26 PM, Joel Harrison, W5ZN via ADXA <adxa at mailman.qth.net> wrote:
> 
> Jussi,
> 
> That is NOT power line noise. That is a noise being generated from another source likely from inside your home and could be a number of things but I can tell you that is NOT power line sparking noise.
> 
> You are correct, power line noise will occur over a broad range of frequencies and one in one isolated small segment. Start turning things off inside your home and shop and see if it disappears.
> 
> 73 Joel W5ZN/ZF2ZN
> 
> -----Original Message-----
> From: adxa-bounces at mailman.qth.net <adxa-bounces at mailman.qth.net> On 
> Behalf Of Jussi Eloranta via ADXA
> Sent: Monday, March 23, 2026 3:45 PM
> To: 'ADXA' <adxa at mailman.qth.net>
> Subject: [ADXA] noise issue - take 2
> 
> Hi,
> 
> Just recorded the 160m noise on the panadapter. I was expecting it to be wide and all over the place. However, see attached. Bog is beverage on ground (wideband resonant) and invL is my inverted L (narrow resonant; SWR only OK at the bottom of 160m). You can see that both spectra are surprisingly narrow. They have center around 1.840 MHz (FT8 160m frequency, of course!) and extend to the sides by about 100 KHz. I was initially looking at this with my inv L and thought that, OK, that must be just the antenna response I am seeing. But now that I see the same thing with the BOG, I am not so sure what to make of this. If I scan more to the AM band, it seems that it is clear over there but then going further down in frequency I find another similar spot that is noisy.
> 
> So, is this power pole noise after all? And if not, what on earth could it be? It has the characteristic raspy tone with multiples of 60 Hz in it. On AM it sounds like the typical power line hum. All that fit power pole noise but the spectrum does not - I think. Furthermore, I do not hear this noise at all on 80m. This is not from my shack as I have turned off power and used the radio on battery power. I do hear something weak on 6m from far away but I have no idea if this is the same thing as what I see on 160m.
> 
> Jussi (aa6kj)
> 
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