I have used a professional ultrasonic parabolic dish while working along
side the local power company (Duke Energy), and were able to find arcing on
almost every pole we looked at and therefore it really made it difficult to
identify the real root cause of the problem. I suggest using VHF or UHF
portable AM receiver with 20 or 30 dB of attenuation that you can switch in
as needed and a 3 or 4 element beam to locate the problem pole, and then
you can use the parabolic dish to locate the faulty component if needed. A
cheap portable police scanner with AM aircraft band makes a great receiver
and they can be had dirt cheap on Ebay. I use 136 MHz AM when trying to
locate the faulty pole (but would also probably use UHF if I had that
Just my opinion having used ultrasonic parabolic dish out in the field.
On Fri, Dec 6, 2019 at 7:40 PM David Eckhardt <firstname.lastname@example.org> wrote:
> This is certainly 120 Hz power line noise. Walk the lines with an
> ultrasonic microphone coupled to a small parabolic or spherical reflector.
> MFJ makes one for about $100.
> Dave - WØLEV
> On Fri, Dec 6, 2019 at 11:54 PM Don Kirk <email@example.com> wrote:
>> Hi Eric,
>> Using a simple PC based sound scope, the bursts of noise are indeed at a
>> frequency of 120 Hz, and looks just most of the power line arcing I have
>> tracked down over the years.
>> I will e-mail you a screen shot of scope capture.
>> Don (wd8dsb)
>> On Fri, Dec 6, 2019 at 4:31 PM Eric Rosenberg <firstname.lastname@example.org
>> > This may not have made it through the first time.
>> > --------------------------------------------
>> > My good friend Tm Shoppa, N3QE has run into a vexing RFI issue.
>> > He posed the following on the PVRC reflector, but is not on the RFI
>> > reflector.
>> > Please feel free to respond directly to Tim.
>> > Thanks & 73,
>> > Eric W3DQ
>> > ------ Forwarded Message ------
>> > From: "Tim Shoppa via PVRC"
>> > Sent: 12/6/2019 3:18:35 PM
>> > Subject: [PVRC] Help me identify my new RFI
>> > In the past week a brand new 24x7 noise source came out of nowhere.
>> > Clearly audible all over my neighborhood under every power line 540kHz -
>> > 1710kHz.
>> > Recording made on 1.8MHz with receiver in 2400Hz bandwidth AM:
>> > http://n3qe.org/n3qe-rfi.wav
>> > Heard in AM, this not simple 120Hz impulse noise but shows strong
>> > 800Hz-1200Hz audio component interrupted at 120Hz. Waveform picture of
>> > the above audio sample shown below (not attached).
>> > Any ideas?
>> > Tim N3QE
>> > _______________________________________________
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> *Dave - WØLEV*
> *Just Let Darwin Work*
> *Just Think*
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