[Antennas] Off Topic: RFI - AM Broadcast

[Tim]

meanwhile back at the shack ...

Well a technician from the local phone company just left my shack and he
came over with a filter of non-descript type and origin. The filter was
black, round, and had no external markings on it that I could identify(can't
see well and did not have my glasses handy. The entire thing was about 3/4'
thick and 1" diameter and had a series of colored wires coordinated to the
contents of the "Box" outside. He said "This might work if not ...." ..
He finished installing it and we came inside and tried the modem once again.
This filter/isolation transformer/whatever worked very well or the radio
station reduced power ahead of schedule. They normally reduce power at 17:00
and this was at 16:30.
I intend to find out exactly what was in that little package and I will
relay the info to the list as an FYI.

On another note ....
For those of you that have access to such stuff ... does anyone know where I
can get AutoCAD Blocks for Schematic Symbols??

> ----- Original Message -----
> Sent: Sunday, November 17, 2002 9:06 AM
> Subject: [Antennas] Off Topic: RFI - AM Broadcast
>
>
> > Starting early Friday morning I started having trouble connecting to the
> > internet. I thought "well water has gotten into the prone box again" (it
> was
> > raining at the time) so I investigated that possibility. That was not
the
> > problem so I pondered other possibilities and came up with nothing
> > reasonable. I had not changed anything about the shack or anything else
I
> > could think of so I decided to call the local phone company and see what
> > information they could offer ... expecting to hear the same interference
> on
> > the handset that I had heard on the modem I picked it up and nothing ...
> > completely clear dial tone. With a confused look on my face I called the
> > phone company and asked them to a technician call me back and again
> > proceeded to ponder the situation. I attempted to identify the source of
> the
> > interference ... I couldn't quite make out what it was I was hearing
> through
> > the modem, but I knew it was voices so I pickup the handset while the
> modem
> > was trying to connect. It was the local AM broadcast station, their
tower
> is
> > about 500 yards north of me and it was their signal I was receiving
> through
> > my modem. To the best of my recollection I do not ever recall having
> > interference like this before so I called the station and asked to speak
> to
> > an engineer to see if anything had been changed about the transmitter or
> if
> > he had heard any other complaints and was their a possibility that
> something
> > had gone wrong. I finally got to speak to the engineer and he said he
had
> to
> > got to the transmitter the next afternoon for a required FCC inspection
> and
> > field strength survey and would this be soon enough to get back to me
with
> > some definitive answers. I agreed and he called me yesterday afternoon
and
> > sure enough nothing was wrong that he could determine. I have yet to get
> > straight answers from the phone company yet other than mine was not the
> only
> > complaint, but there is no one there on the weekend of course.
> >
> > My query in reference to all of this is what could possibly have changed
> > that would allow such a drastic amount of interference in my modem and
> what
> > would you guys suggest as a possible solution? I recently saw postings
in
> > reference to RFI on the list and ordered the "Fair Rite" Catalog, but
with
> > about a dozen visitors over the past 48 hours I have not been able to
> > consider it's contents in this situation. The time is currently 9:52 CST
> and
> > I am sure I will not be able to send this message until dusk when the
> > station reduces power to 5KW so in the mean time with no plans of
visitors
> I
> > am going to try additional grounding and maybe some of the chokes I have
> > taken from other items before I trashed them.
> >
> > Looking forward to your comments.
> >
> > 73 DE KD5CKP
> >
> > - - -
> >
> > Your moderator for this list is:
> > Larry Wilson KE1HZ antennas-owner@mailman.qth.net
> > _______________________________________________
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> > http://mailman.qth.net/mailman/listinfo/antennas
> >
> >
>
>
>