[RFI] RFI Digest, Vol 203, Issue 15

[Hare, Ed W1RFI]

I like what I hard you say in one of your classes, Mike, and that was advice to the repair people to use an ultrasonic sniffer when they got up into the bucket truck, to verify that they can hear the noise ultrasonically. If they can't, it's the wrong pole.

We don't usually recommend to hams that they use ultrasonic equipment. First, the inexpensive products available to hams are not sensitive enough to really rely on them.  Second, it does take some skill and practice, and one can be misled by both corona and by the fact that sometimes, things lika sparking on the top of an insulator can be blocked by the insulator so not seen from ground level. If a ham can find the pole, his job is pretty much done.

But utlitiy personnel should use it, because  they can closer and use it to pinpoint an exact source.

Ed

From: RFI <rfi-bounces at contesting.com> on behalf of Michael Martin <mike at rfiservices.com>
Sent: Thursday, December 12, 2019 10:50 AM
To: Wes Stewart <n7ws at yahoo.com>
Cc: rfi at contesting.com <rfi at contesting.com>
Subject: Re: [RFI] RFI Digest, Vol 203, Issue 15

Everyone has their own opinion,
So here's mine!
I use ultrasound on almost a daily basis. Usually when people have a difficult time utilizing a source on a pole it's because they're on the wrong Pole. using RF to locate the source is highly recommended and a must.
Also keep in mind that ultrasound units such as the mfj is very insensitive but using an ultrasound device such as the radar engineers model 251, Which has probably three times the sensitivity level of the mfj, can produce very good results. Again it's only as good as the previous step so if you haven't verified that the structure you're looking at contains the source you may not be at the source structure there for the results will be poor with the next step. I use ultrasound with about a 95% success rate. Even when I cannot determine the source when using the ultrasound, I can usually determine what it is because the ultrasound doesn't work.
As for the union issue, I've seen a couple of inputs concerning that and the fact is there are Union rules and regulations that limit who can do this, not just a safety standard.  Unions determine, in a lot of companies, who can do what job and high voltage is an area where they often regulate. The hot stick line sniffer that is used on the end of a hot stick is extremely functional and 100% successful. The hotstick line sniffer has an RF detector that works at 114 megahertz as well as ultrasound that is 43 kilohertz. Both work well but may only be used by people qualified to work in the primary zone or within the minimum approach distance.
K3RFI

On Dec 10, 2019, 6:22 PM, at 6:22 PM, Wes Stewart via RFI <rfi at contesting.com> wrote:
>I'm friendly with the RFI sleuth with our local electric coop (also a
>ham).  He tells me that ground level ultrasonic sniffers are pretty
>worthless.  Any physical obstruction attenuates the signal, according
>to him.  They do use one but on a hot stick where it can sniff up
>close.  Unfortunately, it's a union shop so he can't do it and has to
>have a line crewman do it.  The logistics of this are really
>detrimental to efficiency.  (Unspoken opinion of unions goes
>here.......................................)
>Wes  N7WS
>
>
>
>Date: Tue, 10 Dec 2019 17:47:18 +0000
>From: David Eckhardt <davearea51a at gmail.com>
>To: Rfi List <rfi at contesting.com>
>Cc: "Bascombe J. Wilson" <jay.wilson at vodec.net>,    Terry Bullett
>    <tbullett at skybeam.com>,     Ted C <hm55555 at hotmail.com>, Greg Ella
>    <gregella53 at gmail.com>
>Subject: [RFI] ULTRASONICS for RFI SLEUTHING
>Message-ID:
>
><CAODdWWEESYCOMeuRLNXZh2M3_9Bj=xtA=Ypsn4Q7YKmJqhO1KQ at mail.gmail.com>
>Content-Type: text/plain; charset="UTF-8"
>
>Use of an ultrasonic detector is highly useful in finding discharges on
>the
>electric distribution grid, especially localized to the home
>neighborhood.
>Sure, MFJ makes one, but there is an option I ran across on the AirSpy
>group.  if you have a Discovery (or R3 modified HF+) from AirSpy, you
>have
>an ultrasonic receiver.  Have a view of the following link:
>
>            https://youtu.be/H8z02pICisM
>
>--
>Dave - W?LEV
>************************************
>
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