[RFI] New Interference at kk0sd

Don Kirk wd8dsb at gmail.com
Mon Mar 22 03:08:01 EDT 2021


Hi Kim,

You and I are thinking along the same line.  I've been discussing this same
issue with Gary off line as I told him I thought it was odd that he was not
hearing such a strong signal on his portable HF receiver, etc.  I had him
check his portable receiver on his vertical to make sure nothing wrong with
his portable receiver and also asked him if he had another HF antenna
available at his house, and told him to call me today (Monday) to discuss
in more detail.  Since he hears the signal so strong on 20 and 15 meters, a
simple alternative antenna as you mentioned made with wire should tell us a
lot.  I also want to know what antenna he is using with his portable
receiver (and preamp if any), and he can also try connecting that up to his
main radio as a sanity check.

In the back of my mind this kind of reminds me of a case I had a few years
ago at W9RE where 2 different receive systems were used at the same QTH but
spaced a good distance apart.  One of them could easily hear the RFI, while
the other heard nothing, and that is one of the things I have in the back
of my mind depending on what Gary finds out with an alternative HF antenna,
etc. In this previous case the issue was that the noise source was from an
adjacent neighbor who was much closer to the one receive receive array than
the other receive antenna array.  Because of this I was also going to also
ask Gary to report what his portable system in the same general area where
his vertical is located hears even though there is always a chance that
being near his existing vertical will re-radiate the signal, etc.

Just FYI,
Don (wd8dsb)

On Sun, Mar 21, 2021 at 11:08 PM Kim Elmore <cw_de_n5op at sbcglobal.net>
wrote:

> I'm still troubled that it seems you can hear it only on the DX-88
> antenna now that you've ruled out odd stuff in your '847. Here's another
> hare-brained idea: try using a different antenna in your shack. Doesn't
> matter what it is: 10' of wire stuck into the center of the SO-239 on
> the back of your rig. Obviously, don't transmit. Still hear it?
>
> Kim N5OP
>
> On 3/21/2021 9:36 PM, Gary wrote:
> > Kim,
> >
> >       No it's a good idea. I just plugged my TECSUN PL-310 portable
> shortwave into my HF antenna (HyGain DX-88) when I do that I hear the noise
> on the portable...
> >
> >       I do not have another HF antenna, other than a 14 AVQ in pieces in
> my garage.
> >
> >       Keep the ideas coming!
> >
> > 73,
> > Gary "Joe" kk0sd
> >
> > -----Original Message-----
> > From: RFI <rfi-bounces+gary_mayfield=hotmail.com at contesting.com> On
> Behalf Of Kim Elmore
> > Sent: Sunday, March 21, 2021 9:28 PM
> > To: rfi at contesting.com
> > Subject: Re: [RFI] New Interference at kk0sd
> >
> > 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 at rfiservices.com>
> >> Sent: Sunday, March 21, 2021 6:53 PM
> >> To: Gary <gary_mayfield at hotmail.com>
> >> Cc: rfi at 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 at hotmail.com<mailto:
> gary_mayfield at 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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> --
>
> 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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