your noise is caused by loose hardware on the power line equipment.
the three spikes you see per group represent three discharges per half cycle
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On Dec 4, 2019, 5:07 PM, at 5:07 PM, David Eckhardt <davearea51a@gmail.com>
wrote:
>I give up. It's power line discharge.
>Dave - WØLEV
>
>On Wed, Dec 4, 2019 at 11:24 PM Michael Morgan <michael@aa5sh.com>
>wrote:
>
>> I was hoping to get some help identifying a potential source for some
>RFI
>> that started a few weeks ago. I posted some pictures and audio clips
>from
>> 20 and 40 meters on my webpage. Thought it may be easiest there I
>hope it
>> is ok. https://www.aa5sh.com/?p=328
>>
>> I tried to get some screenshots from my 7610. On 20M the Noise
>Blanker
>> does a decent job of removing the noise but on 40M it is a bit two
>random.
>>
>> I have tried turning the main breaker off to my house and use a
>portable
>> radio (Recent RS-918) off a battery and the noise is still there. I
>did
>> walk around my property and noticed no real differences. The odd
>thing is
>> it's kind of random. It has been going to 30 Mins or so and it just
>> stopped for a minute while I've been typing this email for a minute
>or so
>> then started back up.
>>
>> Then at lunch today I took a break and remoted home since I saw where
>10M
>> was open and there was no noise for that 30-40 minutes.
>>
>> I appreciate any guidance you can provide. In my years of radio
>anytime I
>> have had noise problems I have always been able to narrow it down to
>> wall-wart or battery charger.
>>
>> 73
>>
>> Michael, AA5SH
>> _______________________________________________
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>> RFI@contesting.com
>> http://lists.contesting.com/mailman/listinfo/rfi
>>
>One very last try: Copy to Word. Eliminate image. Copy test with no
>image. Paste to email. If this doesn't work, I give up:
>
>In your third image, the audio spectrum, the groups (first peak of
>first
>group to first peak of next group) is 17.5 ms.
>
>
>
>The period on one cycle at 60 Hz is 16.67 ms. Very close. The sound
>clip
>also sounds suspiciously like 60 Hz discharge from the power
>distribution
>somewhere in your vicinity. I usually detect this at 120 Hz as the
>discharge occurs at both the + and - peaks of the sine wave. But not
>in
>this case. In the time domain, I also usually detect an exponentially
>decaying envelope for each discharge. No so in this case. But,
>considering the period and sound, I'd guess its due to power
>distribution
>discharge in you area. Walk the power lines with your battery-powered
>radio. When you find a pole that is particularly, kick the pole hard
>and
>observe any change in the character of the sound on your radio. If no
>change, its not at that pole. Continue searching. Also, damp weather
>usually exacerbates the discharges as does dusty conditions.
>
>
>
>Dave - WØLEV
>
>
>--
>
>*Dave - WØLEV*
>*Just Let Darwin Work*
>*Just Think*
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