I have used this technique, with the cheaper Icom IC-R10 handheld scanner.
I program into a memory bank ham frequencies for each bank, 160 though 1296
MHz, AM detection. With one knob I can then QSY between bands to find the
highest frequency where the noise is present.
During warmer weather, after getting a beam heading from home, I head out
on my bicycle where I have a 2 meter 5/8 wave antenna with a clip on mount
to a metal rack on the back of the bike. As noted, on 2 meters I can hear
most noises within half a dozen poles, and on 432 within one or two poles.
The higher bands (903/1296) have not been useful, at least with the antenna I
I can also carry a 6L 432 yagi on the bike, that I can hook up (while
stopped) to aim at suspect poles. It can sometimes provide useful information
the cross polarization null in the noise. This is most often true when
there is an angled wire running between sources.
When I have a particular pole located, I will drive back with my ultrasonic
detector (W1TRC) to confirm the noise and try to get it down to a
particular location on the pole.
Though like many of us hams, I have lost interest in having talking on a
VHF FM radio from the car, I do usually have one available, with just a 1/4
wave 2M mag mount. I try to keep it tuned to an open frequency with the AM
detector enabled, while driving around close to my house. It can be a good
way to keep track of known noise sources that come and go.
Unfortunately I fall into the group of people that have an unresponsive
power company. The line noise guy is pleasant and I believe knowledgeable,
but getting work done is rare. This is First Energy, which is the same
company that several years ago came within a quarter inch of stainless steel
having a nuke plant melt down in Port Clinton, Ohio. Not a maintenance
kind of culture there.
73 - Jim K8MR
In a message dated 3/29/2011 4:14:08 P.M. Eastern Daylight Time,
Thank you for writing such a great email. You have been so helpful that I
hesitate to add anything, but here are a few comments for this reflector (I
am sure you know this info).
I use the Radar Engineers equipment. I have an RE Model 240 RFI Locator, a
Model 250 Ultrasonic, and a Model 247-B Hotstick Line Sniffer. I think
they are well worth the cost and are invaluable for RFI locating.
I use the method developed by Marv Loftness (KB7KK) as described in his
book "AC Power Interference Handbook, Third Edition", available from ARRL and
HRO (and other places). This method is the one Mike Martin (K3RFI) teaches
in his excellent work shops.
Basically the method involves searching with an AM receiver and compact
beam antenna tuned in the 2 meter band to locate the noise within a few
poles. Then I use a 6 element 440 MHz beam (Cushcraft Model A4496S) to
"the pole". Then I use the ultrasonic the try to locate the offending
(Side bar): I do use the RE 240's scope to get a "fingerprint" of the
interference. Then look for that "fingerprint" in the field. For a description
of this see Marv's book.
I do NOT climb poles. I have used the 247 hotstick sniffer to train
linemen in its use. (I have a small portable noise generator for training).
they use it with a bucket truck to find the problem hardware and fix it.
Note: The lightening arrestors that I have found had NO audio signature.
However, one was so "hot" I got a very strong signal with my 675 MHz 8
element beam. I do usually find an audio signature with the Ultrasonic. This
helps the linemen to identify the problem hardware.
I have also tried locating with the MFJ Model 852, dipole only, power line
noise detector. This has not worked well for me. I would like to try their
Model 856 with the built in 3 element beam. Perhaps this would work well
to get within a few poles of the source. But I believe you really need to
use 440 to 450 MHz to get "the pole".
Well that's about it for now. Thank you again, Frank, I read all of your
postings very carefully.
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