Hi Jim,
I also have 430 MHz portable DF gear including a portable 430 MHz Yagi, and
what I have found is that 136 MHz DF gear is more than adequate in 95 or
greater percent of the time as long as appropriate attenuation is used.
It’s easy for folks to acquire cheap 134 or 136 MHz portable AM receivers
(their 2 meter HT might have that capability and if not then a cheap
portable analog police scanners work great because they typically have
coverage down in the aviation band where AM is used). I now use a Portable
laptop based SDR receiver up on 430 MHz for the infrequent times I want to
confirm my VHF results.
I’ve found it’s typically easy to tell what pole is the source using VHF
when standing off to the side of the line between adjacent poles as long as
I use adequate attenuation ( attenuation sure appears to be the name of the
game in most cases). There are only a couple of times that I have had to
go to UHF to confirm my results when adjacent poles were spaced very close
to each other but it turns out my VHF results did indeed agree with what
UHF indicated. I’ve also tested numerous antennas on VHF for DFing and
find that a 4 element yagi works well.
Just FYI based on my experience.
Don wd8dsb
On Sat, Sep 11, 2021 at 12:43 PM AA5CT via RFI <rfi@contesting.com> wrote:
>
> 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
>
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