I would add my experience this past winter.
I had two instances of very bad QRN on 40M & 80M, one right after the
other.
I was able to pinpoint the direction with my 80M &40M FourSquares,
also plotting on Goggle maps. I next tracked down the actual area
with a K3(pre amp on) and 40M loop. This was much better than using
an Icom R20.
I found the QRN radiated along the power lines for about a mile or so
from the QRN peak. I did not have much luck using the 330/440 Mhz
bands with a 6 element yagi. Did see noise, but not really
definitive. The ultrasound dish really found the fault.
NtStar, the utility, then came out with their Radar Engineering gear.
They got more definitive readings on their RCVR/scope and with
CONSIDERABLE pertinence located the fault with the ultrasound dish.
As Clay noted you have to zero right in on the fault. They let me try
it and it was very, very focused. We eventually found the two
arrestors causing the QRN.
I also had the problem of the noise disappearing in the snow/rain. I
also seemed to see the problem become more intense with the load
increasing at certain times of the day.
What I concluded from all of this was it is important to narrow the
series of poles down to 2-3 and then the utility has a pretty good
chance of finding the fault in one or two visits. The ultrasound is a
little tricky as you need to aim right on the fault as noted.
W1FQ, Thorny
On Aug 2, 2010, at 9:41 PM, Clay W7CE wrote:
> The radio receivers will get you close or maybe even to the pole in
> question, but will not necessarily tell the power company folks
> where the
> problem on the pole is. The ultrasound dish locator that I think
> you're
> referring to will let you locate the actual source on the pole to
> within an
> inch or two. The one that I've used is made by Radar Engineers in
> Portland,
> OR and has a gun-sight on it. As you look at various potential
> problem
> areas on the pole, it will start to make noise when you find it. I
> have so
> many power line problems at my QTH, that the power company finally
> hired a
> consultant that I go out with several times a year. They start by
> listening
> to the noise on my receiver. Then they hook up their receiver
> which has a
> digital scope to my antenna so they can record the noise
> signature. I pin
> point the direction as carefully as possible on 6M using a high 7el
> yagi and
> then print out the direction vector on a GoogleEarth picture
> centered on my
> antenna. So far we have located 8 poles this season. Using the
> ultrasound
> locator, we have identified the exact noise source whether it is a
> loose
> bolt on a cross-brace, an insulator, or a wire that has detached
> from the
> insulator and is arcing against the metallic bracket that holds the
> insulator. BTW, the problem poles are usually located within 3
> miles of
> home and are typically within 100 yards of the vector on my
> GoogleEarth map.
> One final note: we always go pole-hunting on clear, sunny days when
> the
> poles are most likely to be making noise. High humidity and rain
> nearly
> always quiet things down.
>
> It sounds to me like PG&E needs to find someone qualified to hunt down
> power-line noise. If their tech is carrying the ultrasound
> locator, but not
> using it, chances are pretty good that he doesn't know what he's
> doing.
> Don't give up and keep making noise (no pun intended). If they
> don't fix
> the problem, contact the FCC and let them know.
>
> BTW, if you'd like to look at the Ultrasound locator that I've
> mentioned,
> you can see it at:
>
> http://www.radarengineers.com/rfitvi.htm#spark
>
> I have no interest in this company. But I've used their products
> and they
> work.
>
> 73,
> Clay W7CE
>
>
>
> ----- Original Message -----
> From: "Kelly Johnson" <n6kj.kelly@gmail.com>
> To: <Mike@rfiservices.com>
> Cc: <rfi@contesting.com>
> Sent: Monday, August 02, 2010 5:57 PM
> Subject: Re: [RFI] What the ARRL has power line noise?
>
>
>> Mike,
>>
>> After 3 years of trying I finally have the attention of PG&E (thanks
>> to a letter from the FCC of course). They came out and rebuilt a
>> pole
>> about 2 weeks ago, but I still have noise issues. At this point it
>> looks like there are at least 2 sources of noise from at least 2
>> different poles. I could really use your advice about how to help
>> PG&E find the source of the noise. They seem to be just taking my
>> input when I say "I think it is this pole here". They've never
>> really
>> verified exactly where the noise comes from. They just tighten a few
>> bolts and/or rebuild a pole and leave; hoping they fixed it. Not
>> only
>> does this take a long time (they last time they rebuilt a pole was
>> nearly 3 years ago), but at some point I fear they will give up and
>> claim I am chicken little :-)
>>
>> What can I suggest or use or do to really find the source so the
>> fixes
>> are more likely to cure the problem?
>>
>> They have RF-based as well as acoustical equipment, but I've never
>> seen them actually use the acoustical equipment. Will that help?
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