Frank,
I have a friend who has used the RF Gain control as needed, balanced antenna
and accurate, equal measurement of the strength of the noise off center by an
equal number of degrees CW and CCW from the actual direction to determine with
great accuracy the direction of the noise. Then plotting a line using GPS
mapping has actually called the power company telling them the exact pole where
the problem is located without ever leaving his shack. He said he could have
given them the pole number where the line went right through the pole on the
map except for the fact that they had blacked out the number like they do on
license plates. The address had to suffice. Pretty neat!
73... Stan, K5GO
> On Feb 16, 2016, at 9:18 AM, donovanf@starpower.net wrote:
>
> Hi Jeff,
>
>
> My consistent practice is to identify the highest frequency where
> I can hear the RFI in my shack. I then use my directive antennas
> to determine the bearing on which I should search. I can
> consistently determine azimuth within better than ten degree
> accuracy on any band. I begin my search on that frequency
> with the PL-660 in wide band AM mode, walking or driving
> along the line of bearing.
>
>
> The PL-660 has a built in loopstick antenna very useful for
> direction finding but active only in the AM broadcast band
> (540-1700 kHz). Above 1700 kHz it uses a short retractable
> whip antenna (slightly useful for direction finding) or an
> external antenna.
>
>
> Usually (but definitely not always) the RFI can be heard on higher
> frequencies as you get closer to the source, in many cases up the
> the aircraft band or all the way up to 450 MHz (on a different
> receiver). So far my most distant RFI was AC power line RFI
> very strong at my QTH that originates four miles away, It was
> a serious visible arc on a 34 kV subtransmission line (not a local
> 13 kV distribution line). The power company was very
> motivated to repair it quickly.
>
>
> This recent RFI was very different than anything I've ever
> experienced, I could hear the RFI only on the 160 meter band
> (about 1500- 2000 kHz) It sounded like white noise with no
> audible 60 Hz (or 60 Hz harmonic) component, The only
> way I could locate it was by using the PL-660 S-meter with
> the PL-660 in wideband AM mode. It turned out to be a
> malfunctioning Travellers' Information Station transmitter
> at 1700 kHz. Local hams have an excellent relationship with
> the county Office of Emergency Management that operates the
> transmitter and they turned it off within hours of being notified
> of the problem.
>
>
> This is only the second RFI that I've experienced that affects
> only 160 meters. The first one was very intense RFI that
> sounded exactly like classic AC power line RFI but strangely
> it affected only 160 meters and the AM broadcast band.
> It turned out to be a malfunctioning electric fence charger
> one mile away that was stuck continuously on, not pulsing.
> Unfortunately the landowner (an electrician!) was very
> belligerent about refusing to replace his fence charger, but
> some aggressive "social engineering" motivated him to
> change his behavior.
>
>
> 73
> Frank
> W3LPL
>
>
> ----- Original Message -----
>
> From: K1ZM@aol.com
> To: donovanf@starpower.net
> Sent: Tuesday, February 16, 2016 10:08:22 AM
> Subject: Tecsun 660
>
> Hi Frank
>
> I read your emails on your RFI search.
>
> Youmay have mentioned it, but what FREQ BAND did you use on the TECSUN in
> your search for the source?
>
> Was it the AIRCRAFT BAND on FM?
>
> The reason I ask is that I have a similar radio - that is very similar to
> the radio you used - just made by SONY.
>
> I wonder if I could use it like you did? I am 99% sure it has the aricraft
> FM band in it.
>
> Pls let me know when you can.
>
> Tks
>
> 73 JEFF</HTML>
>
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