[RFI] Regular birdies
Gary at ka1j.com
Sun Oct 2 21:34:59 EDT 2016
This will be a bugger I think. If... its
coming from the airport, they likely won't
let me go snooping around, not with
today's tightened security. I'll have to
take the back-up K3 out and see what I can
find but DFing these relatively faint sigs
on 80 & 160 will be a bugger.
Be easier if they showed up on all the
other bands, a DFing antenna would sure
I see your interference and this does have
a whistling/wavering sound to them, they
don't drift but sometimes it almost sounds
like they're heterodyning.
What was it you found to be the source?
> I tracked down a "wavering carrier" I had on 160 meters to a residence
> 1.9 miles away to my north. This is in a city/suburban environment
> over relatively flat, but conductive (30 mS North Texas) earth. I make
> mention of this ONLY to give some idea of how far away these noise
> sources or signals can be! I notice you have 'humanity' (houses or
> homes on lots) west of you out past the airport about two miles or so
> I tracked two other such "carriers" to two other discrete residences
> to my SSW and W at about 3700 ft and 4200 ft respectively. I have been
> out with different gear at different times to confirm this, using
> different receivers (including DF receivers) as well (i.e., I can
> circle the block and the DF antennas continue to indicate a specific
> residence). These 'carriers' are also receivable in the 80 meter band.
> Here is a sample of the carrier at it appears on 80 meters (it makes
> kind of a tea kettle whistle sound):
> I think you are going to have to track this down (the 'hard', old
> school way) as you indicted in your previous post in order to next
> identify the source.
> 73, Jim WB5WPA
> From: Gary Smith <Gary at ka1j.com>
> To: RFI at contesting.com
> Sent: Sunday, October 2, 2016 5:09 PM
> Subject: Re: [RFI] Regular birdies
> Unfortunately, these birdies are not from
> within this house.
> I killed the power to the house, ran the
> 12V equipment, the K3s and P3 from a
> battery and they still come out just as
> strong on both the vertical and the HI-Z 8
> element. There are some directions the
> HI-Z kills the birdies in.
> What is difficult for me to picture is,
> direction-wise, they seem to have a strong
> signal coming from the west but to the
> west is nothing but marsh, ocean, a
> peninsula, more salt water and finally an
> airport a couple miles away.
> Since this appears to come from a power
> supply or some electronic device and most
> likely close by, I'm at a loss. My nearest
> neighbors aren't the type to let someone
> into their house to sniff the air and I'm
> not going to deal with them at this point.
> What might be a workable but expensive
> solution is to find a NCC-1 and use both
> the 8 element HI-Z and the 3 element HI-Z
> to null out the interference.
> Now to see if I can find a used NCC-1 at a
> reasonable price.
> The beat goes on.
> > Not really sure that I'd call them birdies
> > but here is a family photo of them seen on
> > the P3:
> > http://doctorgary.net/RFI-K3s.jpg
> > they are regular at 8.02
> > 3.506.07 MHz
> > 3.514.09
> > 3,522.12
> > 3.530.14
> > 8.02
> > 8.03
> > 8.02
> > I see them with both the Inv-L and the Rx
> > antenna but much more pronounced on the
> > Inv-L
> > They're not on all bands but I come across
> > this all too often. I've looked at the
> > coax connectors and all are tight. Any
> > suggestions?
> > Thanks & 73,
> > Gary
> > KA1J
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