We recently found a faulty lightning 'arrestor' on a pole by using both the
MFJ device and a small shielded loop (easy home brew project) into a
battery-powered receiver. We had two of us in the field. One wielded the
MFJ and I had the small (0.5-meter) shielded loop fed into the Yaesu VR-500
on 1.830 MHz (160-meters). We both independently found the same source /
pole in the field. The null on the shielded loop is extremely sharp and
this piece of hardware should be in the bag of tricks of anyone sleuthing
RFI. It is a powerful tool when coupled to a battery-powered receiver with
its extremely sharp null (perpendicular to the plane of the loop). One
doesn't need something as large as the 'Flag" that was recently published
in QST and referred to in a previous post in this thread. Another plus
for the shielded loop is that in the field, one can tune the receiver to
the worst-case frequency of the RFI as I did in the related story, above.
The shielded loop is untuned. The MFJ relies only on VHF noise. In some
cases, an ultrasonic microphone at the focus of a small parabolic or
spherical reflector is good at finding coronal discharges as well as active
arcs and discharges. MFJ also makes that at a reasonable price.
Our power provider was out the next day to fix the problem. We even gave
them the pole number which is a great help to any power provider.
Dave - WØLEV
On Mon, Mar 22, 2021 at 2:28 AM Kim Elmore <cw_de_n5op@sbcglobal.net> wrote:
> It's odd that you can't hear it on your portable rx. That made me
> curious: What if this is something internal to your '847? Have you tried
> pulling your '847 and listening on a different receiver using the same
> antenna? If you have, do you still hear the noise? It's a long shot, but...
>
> Kim N5OP
>
> On 3/21/2021 7:28 PM, Gary wrote:
> > Mike,
> >
> > Thanks for the info. I understand locating the noise is
> more important than identifying the noise. I am just try to play all the
> angles as I was hoping to work the WPX contest nest weekend. I have been
> walking the neighborhood a good chunk of the afternoon, and have not been
> able to hear the noise on my portable shortwave and loop antenna. It is as
> strong as ever on my home station.
> >
> > I have an MFJ 852 Noise Finder and it seems to go crazy
> when broadside to any house. The neighbors on each side of me drive the
> meter full scale.
> >
> > Yep I only want to knock on one door, as I know that
> can get dicey. I would rather place a call to a utility, but can’t really
> do either until I know.
> >
> > Keep the suggestions coming!
> >
> > Thanks and 73,
> > Gary “Joe” kk0sd
> >
> > From: Mike Martin <mike@rfiservices.com>
> > Sent: Sunday, March 21, 2021 6:53 PM
> > To: Gary <gary_mayfield@hotmail.com>
> > Cc: rfi@contesting.com
> > Subject: Re: [RFI] New Interference at kk0sd
> >
> > Joe I haven't had time to read all the other input but I can tell you it
> is not an arcing source or a sparking source. either one of the two would
> be much broader than what you're reporting. if someone were to tell you
> exactly what it is you really wouldn't be any further ahead. You would
> still have to find which residents or business it's in. My suggestion would
> be to either go mobile or on foot, preferably on foot listening to the
> frequency that you know the problem affects. once you locate the residents
> then go through the breaker scenario and locate what the source is. Be 100%
> certain of the structure or home that the problem is in before knocking on
> the door. The last thing you want to do is start guessing. Guessing we'll
> ruin the relationship with your neighbors.
> > Be safe,
> > Mike k3RFI
> > www.rfiservices.com<http://www.rfiservices.com>
> > Get BlueMail for Android<http://www.bluemail.me/r?b=16696>
> > On Mar 21, 2021, at 2:01 PM, Gary <gary_mayfield@hotmail.com<mailto:
> gary_mayfield@hotmail.com>> wrote:
> >
> > My last problem was tracked down to a neon sign in a neighbors garage. I
> had several months of blissful relatively low noise operation, but now have
> a new RFI issue.
> >
> > You can see a recording of it here:
> > https://www.youtube.com/watch?v=GKf4P44FXMo
> >
> > I have turned all of the breakers in my home off and run the radio from
> a battery and the noise remains.
> >
> > My neighborhood utilities are all underground.
> >
> > There are no solar installations in my neighborhood, and the noise is
> there at night anyway...
> >
> > The noise is not detectable on the AM broadcast band, but starts around
> 2 MHz and runs to at least 6 meters.
> >
> > It is there 7 days a week 24 hours a day.
> >
> > It is not detectable from my pickup when I drive the streets of my
> neighborhood (checking both AM broadcast and Shortwave).
> >
> > If any one has heard something like this, I would love to hear what you
> found.
> >
> > Thank You for your input and help!
> >
> > 73,
> > Gary "Joe", kk0sd
> >
> >
> > ________________________________
> >
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> > RFI@contesting.com<mailto:RFI@contesting.com>
> > http://lists.contesting.com/mailman/listinfo/rfi
> > _______________________________________________
> > RFI mailing list
> > RFI@contesting.com
> > http://lists.contesting.com/mailman/listinfo/rfi
> --
>
> Kim Elmore, Ph.D. (Adj. Assoc. Prof., OU School of Meteorology, CCM, PP
> SEL/MEL/Glider, N5OP, 2nd Class Radiotelegraph, GROL)
>
> /"A great second violinist plays second fiddle to no one." //– Robert C.
> Marsh, Chicago Sun-Times./
>
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> http://lists.contesting.com/mailman/listinfo/rfi
>
--
*Dave - WØLEV*
*Just Let Darwin Work*
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