Hi John,
I normally first try and determine if the noise is power line related
(arcing), and this can typically be done right in the shack. Using a
receiver in AM mode and with filter set wide, look at the audio output of
the radio using a scope. You don't need an oscilloscope, you just need a
scope capable of audio frequencies, and there are numerous online scope
applications you can download and run on your PC. I use "soundcard scope"
on my laptop, and you can download it at http://www.zeitnitz.eu/scope_en
If you have a laptop with a built in mic, you don't need to do anything
else other than run the software to look at the audio output of your radio
via the built in microphone on your laptop. Arcing power lines typically
show a pulse at a frequency of 120 hertz when they are arcing during both
the positive and negative half of the sine wave (this is what I commonly
see).
Actually on my Kenwood TS180s, if the built in noise blanker does not make
the broadband noise vanish, I know it's not power line arcing.
If it's not power line arcing related, then I know I should stick with HF
direction finding equipment (not an AM radio up on VHF or UHF), and I also
then try and avoid walking close to power lines so local noise on them does
not confound my portable direction finding activities.
If you want to send me an audio recording of your noise (AM radio with wide
filter selected), I would be glad to take a look at the waveform. Send me
a .wav file or similar format.
I have never found the need to turn off power to my home to locate a noise
source as long as I have a directional antenna that tells me the noise
source is arriving from a direction not towards my house, but this is never
a bad first step if you don't mind resetting clocks, etc.
73,
Don (wd8dsb)
On Tue, Apr 19, 2016 at 11:10 AM, john@kk9a.com <john@kk9a.com> wrote:
> I have a constant noise source that is loud on 10m and 15m. I got a beam
> heading and then I walked along the main road where the power lines are
> with my Tescun PL-660. I listened on 10m using the built in antenna set
> for DX sensitivity and outside of an inconsistent short noise burst I
> heard nothing. How close to the noise do I need to be to pick it up with
> this receiver and built in antenna? Is there a better antenna that I can
> use with the Tescun for locating the source?
>
> John KK9A
>
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