"N8KDV" wrote in message
...


Dave wrote:

I recently hooked up a thirty-six foot (plus or minus a couple of feet)
piece of four-stranded wire with alligator clip to the internal "whip"
antenna of my portable shortwave receiver, for the extra performance
such a
device offered. It works so well that I now cannot usually use my "DX"
setting because of all the background noise (sounds like hundreds of
other
broadcasts vying for attention.) I don't know the frequency source of
all
this background noise, but would like to filter out as much of it as I
can.
One manufacturer of a similar "wind-up" antenna adds a capacitor to the
wire
in order to lower the resonance frequency of the wire. If I were going
to
try something similar (adding a capacitor, in series) in an attempt to
bring
the resonance of the wire down into the 30 MHz range, what size
(roughly)
capacitor should I use? Should I just try a few with different ranges,
or
does anyone here have any suggestions?

What receiver? It sounds like it's being overloaded.



Sorry, forgot to include that information. I am using a DX-402 (aka Sangean
ATS-505). I honestly wondered about that, but hesitated to shorten the wire
because I would (obvioiusly) lose some sensitivity, and really like being
able to pick up VOK's English broadcasts to Central America. Only problem
is the noise that makes it difficult to single out.

Thanks,

Dave