Mike Martin's course very specifically points out that one should do exactly
what I suggest, Jim. A very strong source, even on UHF, will be heard when you
point your directional antenna towards the lines, so it is possible to get
fooled. That extra step can save a misdiagnosis, especially if a source is
coming from a house. I'd spend the extra five minutes to be sure. I guess you
would not.
________________________________
From: AA5CT <jwin95@yahoo.com>
Sent: Saturday, September 11, 2021 12:43 PM
To: RFI List <rfi@contesting.com>; Stephanie WX3K <wx3k@ptd.net>; Hare, Ed,
W1RFI <w1rfi@arrl.org>
Subject: Re: [RFI] Working with Utilities
re: "That is half of the equation."
Beg your pardon here Ed Hare.
I don't know what you read into my reply Ed, but, that is not my experience with
this technique! Note I said UHF, not VHF and with a handheld Yagi antenna. I
have
even tried a 900 MHz Yagi to do the DF, but the amount of signal there is
notably
down from that at UHF (450 MHz).
Ed, it becomes QUITE apparent when using this UHF DF technique in the field
WHERE the source is, where the RF is coming from, and its definitely NOT from
'all along the line' as you seem to indicate. AND its easy to note if it comes
from
a house or from hardware up on a pole.
There is even a POLARITY associated with these noise sources - orienting the
Yagi vertically and horizontally results in changes in signal strength.
I don't know that you've ever tried this UHF AM rcvr plus beam technique in the
field, Ed, but it becomes quite apparent when actually using this technique just
where the noise, where the signal originates.
Again, walk around, sniff the noise source with your HAND-HELD UHF beam
and note WHERE the signal is strongest. You'll find it. Note: Use AM rx mode
on the receiver, and you'll hear the characteristic 60/120 Hz (base rep rate)
'buzz' of the arcing source.
This technique (USED to find the individual offending pole) has not failed me
yet.
And, AGAIN, I use other techniques (LIKE HF DF) to locate down to the vicinity
of the offending pole.
THIS response, this e-mail, was directed to the original poster in this thread
to
help ID and note an arcing set of BELL insulators, that was all. But Ed took it
in a more general direction.
de AA5CT Jim
---------------------------------------------------------------------------
On Saturday, September 11, 2021, 10:03:02 AM CDT, Hare, Ed, W1RFI
<w1rfi@arrl.org> wrote:
That is half of the equation. The lines are radiating, even on VHF, so what
you need to do it to go across the street from the pole you think the source
is. Do note that the noise gets stronger when you point at the pole. Make a
note of the s-meter reading. Now, go up the street to the next pole, across the
street at the same aprpriximate distance. Get an S meter reading If it is
stronger, your first pole was not the pole. Keep going. The noise will be
significantly stronger on the actual pole.
Now, if the source is NOT on the pole but from a nearby house, you will find
that it is stronger on the pole that has a transformer connected to the
offending house. In that case, compare poles with transformers, and when you
find that pole, point the Yagi at nearby houses.
Keep in mind that in this day and age, people will be very suspicious of you,
so you either need to let the police know what you are doing, or be prepared to
offer explanations when they arrive.
From: RFI <rfi-bounces+w1rfi=arrl.org@contesting.com> on behalf of AA5CT via
RFI <rfi@contesting.com>
Sent: Saturday, September 11, 2021 9:13 AM
To: RFI List <rfi@contesting.com>; Stephanie WX3K <wx3k@ptd.net>
Subject: Re: [RFI] Working with Utilities
Hand-held UHF Yagi - can you point a Yagi at the offending pole with those
insulators and demonstrate THAT is the source of noise?
It's most convincing when you can swing the beam back and forth and
the noise picks up when pointing at the offending hardware.
Reference: https://powerlinenoiseallentexas.wordpress.com/df-equipment/
de AA5CT Jim
-----------------------------------------------------
On Friday, September 10, 2021, 9:42:33 PM CDT, Stephanie WX3K via RFI
<rfi@contesting.com> wrote:
All
I live near the territory boundary of two utilities. My work with PP&L has
fruitful and they have been very cooperative in resolving RFI issues i would
report to them over the years.
I have been struggling with MetEd for the same powerline noise for at least 5
years now. I recently got their attention again and reopened a new work order.
I spoke to their tech today and learned they have been replacing cut-outs and
repairing resistive connections. All good but my RFI issue continues mostly
driven by drier windier weather conditions, the RFI swamps the 25-150 MHz
spectrum.
https://www.dropbox.com/s/ekn6xpl0960qrm7/IMG_9711.MOV?dl=0
There are old bell type insulators on poles near this suspected line area. I
consistently request they replace those problematic antiquated bell insulators
that are notorious for RFI issues. They(MetEd) seem to avoid this. With my work
with PP&L, replacing those bell insulators have completely resolved those
reported issues. The techs from MetEd use their ultrasonic detectors to find
issues but it is my impression these bell type insulators do not show up as
issues when they look around with their ultrasonic detectors. True statement ?
How does one convince a utility to actually listen to the RF spectrum for
issues ? Is there a specific model spectrum analyzer that the utilities tend to
use to scan for RFI ???
Stephanie WX3K
_______________________________________________
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
_______________________________________________
RFI mailing list
RFI@contesting.com
http://lists.contesting.com/mailman/listinfo/rfi
|