[Top] [All Lists]

Re: [RFI] RFI Digest, Vol 203, Issue 15

To: "Hare, Ed W1RFI" <w1rfi@arrl.org>
Subject: Re: [RFI] RFI Digest, Vol 203, Issue 15
From: Michael Martin <mike@rfiservices.com>
Date: Fri, 13 Dec 2019 12:30:24 -0500
List-post: <mailto:rfi@contesting.com>
Thanks Ed

⁣Get BlueMail for Android ​

On Dec 13, 2019, 5:34 AM, at 5:34 AM, "Hare, Ed  W1RFI" <w1rfi@arrl.org> wrote:
>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.
>From: RFI <rfi-bounces@contesting.com> on behalf of Michael Martin
>Sent: Thursday, December 12, 2019 10:50 AM
>To: Wes Stewart <n7ws@yahoo.com>
>Cc: rfi@contesting.com <rfi@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
>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.
>On Dec 10, 2019, 6:22 PM, at 6:22 PM, Wes Stewart via RFI
><rfi@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
>>Wes  N7WS
>>Date: Tue, 10 Dec 2019 17:47:18 +0000
>>From: David Eckhardt <davearea51a@gmail.com>
>>To: Rfi List <rfi@contesting.com>
>>Cc: "Bascombe J. Wilson" <jay.wilson@vodec.net>,    Terry Bullett
>>    <tbullett@skybeam.com>,     Ted C <hm55555@hotmail.com>, Greg Ella
>>    <gregella53@gmail.com>
>>Content-Type: text/plain; charset="UTF-8"
>>Use of an ultrasonic detector is highly useful in finding discharges
>>electric distribution grid, especially localized to the home
>>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
>>an ultrasonic receiver.  Have a view of the following link:
>>            https://youtu.be/H8z02pICisM
>>Dave - W?LEV
>>RFI mailing list
>RFI mailing list
RFI mailing list
<Prev in Thread] Current Thread [Next in Thread>