[SkyHub] Power Line Noise

[Harold Hallikainen]

I have generally found that power line noise is worse on low frequencies.
Determining the location is best done with a VHF or UHF AM receiver. HF
noise travels along the power lines and establishes standing waves, so
there will be peaks and nulls all over the place. The MFJ power line noise
receiver is a 100 MHz AM receiver. The receiver Xcel uses is 300 MHz. Once
they find the area with the 300 MHz receiver, they use an ultrasonic
receiver with a parabolic reflector. With the ultrasonic receiver, he was
able to identify a lightning arrestor that was making noise.

I look at power line noise as a 120 Hz modulated spark transmitter. There
is a distinctive sound and, as shown on my power line noise page (
https://w6iwi.org/PowerLineNoise/ ), very distinctive on a scope.

I've been thinking of writing a web application that could be called up on
a cell phone. Audio in (even just through the phone microphone) would be
analyzed for a "signal to noise ratio" where the "signal" is the power
line noise. This SNR with GPS would be logged to plot noise contours on a
map. The cellphone would be fed with a VHF or UHF AM or SSB receiver. For
example, my IC-7100 can do AM or SSB on VHF and UHF. So, the hope is that
I can set the cellphone near the receiver, drive around, and then plot the
"SNR" to determine the source of noise.

That's the idea, anyway! Another project!

Harold


>  Harold,Most sincerely, Thank You for the offer! I have things I must
> finish before I bite this off, but one of thesedays ( within the next two
> months ) I will be coming to you to borrow it. This thing has bothered me
> forover three years, unceasingly riding at S7 to S9; the S9 level is
> calibrated at 50 microvolts. It occasionallypops up to 20 decibels over
> S9. I cut off all 120 / 240 volt power to the duplex where I live just to
> be certainthat it wasn't something there. I drove the neighborhood with
> my mobile on the 20 meter band and the noise follows the power lines,
> but couldn't discern any rise or fall in strength that would point me to
> thesource. The noise is at its most horrendous strength at 40 and 20
> meters although still bad enoughon 80 meters that I can't really hear a
> net control station in Colorado Springs. It drops off rapidly rightat 15
> megahertz.                                       
> Â Christopher C. Campbell, N0NDFÂ  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â  Â 
> Â  Â  Â  Â  Â  Â  Â 707-330-5298
>     On Monday, January 4, 2021, 08:31:57 PM MST, Harold Hallikainen
> <harold at mai.hallikainen.org> wrote:
>
>  There was a discussion of power line noise on tonight's net. My
> adventures
> in power line noise are at https://w6iwi.org/PowerLineNoise/ .
>
> In particular, see the ARRL power line noise mitigtation form. Filling out
> this form got Xcel out here, and they solved the problem in my area.
>
> Also, if anyone would like to borrow it, I have an MFJ power line noise
> receiver that can be used to hunt down the noise source.
>
> Good luck!
>
> Harold
> https://w6iwi.org
>
>
>
> --
> FCC Rules Updated Daily at http://www.hallikainen.com
> Not sent from an iPhone.
> ______________________________________________________________
> SkyHub mailing list
> Home: http://mailman.qth.net/mailman/listinfo/skyhub
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:SkyHub at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>   ______________________________________________________________
> SkyHub mailing list
> Home: http://mailman.qth.net/mailman/listinfo/skyhub
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:SkyHub at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html


-- 
FCC Rules Updated Daily at http://www.hallikainen.com
Not sent from an iPhone.