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[RFI] Line Noise

To: <rfi@contesting.com>
Subject: [RFI] Line Noise
From: tduffy <tduffy@sygnet.com> (tduffy)
Date: Sat, 28 Feb 1998 19:36:12 -0500
owner-rfi@contesting.com wrote:

> >From k3lr  Sat Feb 28 19:16:26 1998
> Received: from migate.ampr.org (sapgate.freeway.net [206.153.72.61])
>         by dayton.akorn.net (8.8.5/8.8.5) with SMTP id TAA23191
>         for <rfi@contesting.com>; Sat, 28 Feb 1998 19:16:25 -0500
> (EST)
> X-BBS-Msg-Type: P
To: <rfi@contesting.com>
> Date: Sun, 01 Mar 98 00:14:10 +0000
> Message-Id: <5939@migate.ampr.org>
> From: i4jmy@migate.ampr.org
> To: rfi@contesting.com
> Cc: thomas@cybrzn.com
> Subject: Re: Line Noise
>
> Message-Id: 5939_migate
> From: i4jmy@n8it.#nwmi.mi.usa.noam
> To: rfi@contesting.com
>
>   Hi Guys,
>
>   the real drama is not the line noise, but to depend on someone else
>   will, for the "official" search and solution.
>   Read books can't solve the problem if who materially search and
>   repair "has no hears" and/or follows other purposes (to delay).
>   Here, you can forget to be considered by the electrical company if
>   complaining as a private citizen. In my country to force the
> electric
>   company (just one is existing) to act against a line noise problem,
>   there is nothing else than the official way.
>   Apparently easy, this official way is practically long, bureaucratic
>
>   and still doubtfully effective.
>   So, who suffers the interference must send a written complaint to
> the
>   office of regional department for telecommunication, an office that
>   is depending by the communication ministery.
>   The complaint must be detailed because other than veryfing what is
>   descripted, this office won't do.
>   The need to find out the exact source of noise, before starting the
>   official procedure, is the obvious consequence to have a chanche of
>   success, but this is a big challange without specific
> instrumentation
>   and experience.
>   Weeks or months after the complaint, notified to compliant and to
>   the electrical company to send representatives in the date of
> veryfy,
>   they will go in the indicated area. If the noise is present when
> they
>   check, they will give a term within the noise has to be eliminated.
>   Since a deny to act brings to a legal action, I know the electrical
>   company even replaced all the insulators along 7 Km power line to
>   solve a problem they couldn't fix in a short time otherwise.
>   As it is easy to understand, apart our specific situation described
>   above, pointing at the real source of the noise is probably a big
>   help in any case, expecially when it is possible "get in touch" with
>
>   the electrical company without need of a third entity.
>   Localizing a problem, infact, could make not so titanic, long and
>   expensive the work to fix the noise, and the electrical company
>   won't deal, at least, in the search of the originating device.
>   It is practical to realize that in 99% of the cases they won't gain
>   anything by fixing their line noise, while to do it they have an
>   economical cost to pay.
>   Speking about our specific problem it is mainly affecting 10 meters,
>
>   but this could be a matter of radiation angle and orientation
> between
>   our antenna and the line that is also radiating, I think.
>   I investigated the problem along the line with an antenna that is
>   flat in gain and responding to the electrical field (short active
>   antenna), along some 10 KM the line is noisy from 0.1 to 30 MHz and
>   more.
>   When the line arrives to substations, the derivated lines are noisy
>   by only few hundred meters, less if in between there are
> transformers.
>
>   The line is a 150KV AC, not the highest voltage and power around
>   here, but looks like if once it was a main line (old line).
>   The noise is higher and lower point to point and sometimes stops,
>   just like if something is intermittently arcing.
>   Wet and humid weather often produce a NO NOISE period, dry weather
>   causes a rise in the noise.
>   Looking with powerful binoculars, all the surface of each glass
>   insulator (composed by 8 conical stacked ones) is covered by a
>   reddish powder. The powder density is maximal around the metal
>   junctions and decreasing toward borders.
>   A qualified employed in the electric company (informally) told me
>   they check the lines, in search of this interferences, with special
>   infra-red binoculars (can be performed in daylight).
>   I couldn't find anyone else having such a tool.
>   Is there anyone who tried infra-red or alternative method without a
>   big expense ?
>   Any practical suggestion is welcome.
>
>
>   73,
>   Mauri I4JMY
>
>   e-mail i4jmy@migate.ampr.org




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