On Sat, 3 Jan 2004 23:45:31 -0600, "H Davis" hdavis@(no
spam)ntsource.com wrote:
Hi Harlan,
This seems to be a significant clue:
since the radios do not accept the same plug.
snip
This setup left me able to receive more than I could with about 25 feet of
multistrand, speaker wire tossed out the basement window and anchored up in
a tree next to the window, but it is noisy. Lots of static, but turning off
various things (computers, fluorescent lights, dimmers, etc.) doesn't seem
to reduce the noise. I noticed that when attaching the antenna to the whip,
I was getting pretty good reception and less noise when the alligator clip
was about two inches from the whip. For some reason I decided to wrap about
50 loops of the #14 insulated wire around a piece of 1 1/2 inch PVC pipe
and bare one end of the coil for attachment to the alligator clips. I
slipped the coil over the whip, attached the clip to the bare portion of the
wire forming the coil and I get pretty decent reception with less noise that
with the clip attached directly to the whip. Clipping the alligators to the
insulation on the end of the coil I get even less noise, and still pretty
decent reception.
Why does this work? Is there anything else I can do with the current setup
to improve things? Until spring arrives I'm not even going to think about an
outside antenna. What mistakes did I make? How is the current setup going to
limit reception on various bands? How will it improve reception relative to
just the whip (which is kind of useless in the basement, anyway)?
Did I do anything right? Did I do anything wrong? I see SWL as essentially
experimenting with antenna configurations. Is this a valid way to look at
it?
Harlan
You are on the right path. However, as to the "clue" above. I am not
familiar with the specific models, but I have every suspicion that the
whip antenna is for FM only, and AM/SW is achieved through either a
ferrite bar antenna inside, or an external connection, or both. Your
windings are not really coupling into the whip but rather this
internal antenna, and they are still too far apart. However, barring
a more detailed description, this is just a guess.
Do your receivers have any kind of jack that is not audio or power?
Chances are that is an external antenna connection, especially if
there is a switch nearby. If so, that is the proper way in with your
wire antenna and it will make a significant difference. I say this
because it sounds like the noise is from your having the gain set all
the way up, and what would be strong signals are competing with weak
noise. The reason why the strong signals are not booming in, is you
haven't made a good connection. The other possible answer is that you
are in fact deep in a very noisy environment and your antenna is doing
the best it can.
73's
Richard Clark, KB7QHC
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