Once on site, you might try a much smaller loop instead of a 'real' antenna.
Dave - WØLEV
On Sun, Jan 12, 2020 at 6:14 PM Lee STRAHAN <k7tjr@msn.com> wrote:
> Kenny and All,
> I have a noise here in Central Oregon that sounds very similar to the one
> you are chasing. There is a wood products plant about 2000 feet from my
> shack and antennas. The noise is worst on 160 meters and extends up to
> about 5 MHz and not detectable above that range as far as I know. It is a
> raspy sizzling noise that changes all its sidebands as you travel along the
> power lines. I tried low frequency loops and VHF etc with no success of any
> antennas pinpointing the problem. Even a professional locator group paid by
> the power company tried with no success. I knew I could easily hear the
> noise on my car AM radio at the top of the AM band and multiple trips right
> out my driveway toward the plant gave indication but no actual hotspot. I
> make high impedance antennas (you could call one an e-probe) so I put a 4
> foot converted vertical on the back of my pickup truck with a wideband high
> impedance amplifier and the suitable power injection. I fed this to an
> SDR-IQ radio and laptop combination. What I could see of this interference
> was astounding. The computer display showed hundreds of signal peaks that
> varied by a very large amount as I moved along the power lines. This may be
> the reason you cannot pinpoint (in my case) the exact location because of
> the many varying sidebands included in the interference. With the wide band
> display I was able to drive 1 1/2 miles down the road where I could still
> see the interference, turn around and drive right to the business with a
> peak of wide bands of noise right at the power pole feeding that building.
> These power lines also feed my property. At first I thought it was their
> 100 HP air compressor but when they shut it off the noise remained. I now
> suspect another commercial device they have which is a large glue pot with
> a continuous temperature controlled heater. At least the company is working
> with me and allowing me to help pinpoint the offender. I first gave them
> the introduction letter from the NK7Z site or ARRL I cannot remember which.
> They actually consulted with someone that gave them the opinion that they
> indeed needed to fix the problem. They did not share with me whom they
> spoke with.
> The point to all this is try looking at the noise with a SDR radio that
> should give you a wider bandwidth picture. It sure worked for me under very
> similar circumstances.
> Lee K7TJR OR
>
> -----Original Message-----
> From: RFI <rfi-bounces+k7tjr=msn.com@contesting.com> On Behalf Of Kenny
> Silverman
> Sent: Saturday, January 11, 2020 8:03 PM
> To: jwin95@yahoo.com
> Cc: RFI <rfi@contesting.com>
> Subject: Re: [RFI] Guidance on finding noise?
>
> The noise is mainly on 160. Slight to no noise on 80/40, and no detection
> at AM VHF.
>
> Regards , Kenny K2KW
>
> > On Jan 11, 2020, at 10:16 PM, AA5CT <jwin95@yahoo.com> wrote:
> >
> >
> > Kenny,
> >
> > Did you whip out your VHF and UHF beams with an AM rx mode receiver
> > once close to the suspect poles? That is the only way, and it is a
> > conclusive way, that I have found to ID noisy power poles once the HF
> > DF loop gets you in the area of the noise source.
> >
> > de AA5CT
> >
> > .
> > .
> > On Saturday, January 11, 2020, 9:03:04 PM CST, Kenny Silverman <
> kenny.k2kw@gmail.com> wrote:
> >
> >
> > KC4D,N3AC and N3CW went hunting with a KX3 and a DX Engineering
> Amplified RX loop and again didn’t find anything conclusive. Basically they
> said the loop performed about the same as one of the AM radios we have
> that’s fairly directional.
> >
> > We’ve been looking so many times that we’re getting frustrated. There
> > are a few noisy clusters, but we can’t find a specific pole or house.
> > Nor can we assess if the noisy areas are actually the key offender(s)
> >
> > Do we call in the clusters we found ? Or do we really need to pinpoint
> the source(s) better before we ask for crews to come out? We’re concerned
> about crying wolf and/or giving a list of more than a dozen poles for the
> power company to look at.
> >
> > Regards , Kenny K2KW
> >
> > P.S. the only success so far is fixing my subject line typo 🤓
> _______________________________________________
> RFI mailing list
> RFI@contesting.com
> http://lists.contesting.com/mailman/listinfo/rfi
> _______________________________________________
> RFI mailing list
> RFI@contesting.com
> http://lists.contesting.com/mailman/listinfo/rfi
>
--
*Dave - WØLEV*
*Just Let Darwin Work*
*Just Think*
_______________________________________________
RFI mailing list
RFI@contesting.com
http://lists.contesting.com/mailman/listinfo/rfi
|