"Joerg" wrote in message
...
amdx wrote:
"Joerg" wrote in message
...
amdx wrote:
"Richard Clark" wrote in message
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On Fri, 19 Mar 2010 15:22:42 -0500, "amdx" wrote:

So I installed the antenna on the outside of the boat and the radio
inside,
now one station I listen to is weak, but if I unplug the antenna and
let the
center pin touch ground of the connector on the radio it comes in
great.
Just curious why it is working this way.
Hi Mike,

You moved the antenna.

Most loss of signal as you describe comes from not being a weak
signal, but the mixture of signals that combine negatively at some
spot due to multiple reflections. When you replaced the line cord as
antenna for this better implementation, you also found that "sour (not
sweet) spot." This can occur for any frequency with the equal
likelihood of reflections combining negatively. Move your antenna a
quarter wave and see what happens.

Your description of your having an aluminum boat almost guarantees a
multitude of RF-bright reflections. At short wavelengths, this also
guarantees many, many regions that will exhibit destructive (as well
as constructive) combinations of those reflections.

Put your antenna as far away from the superstructure or hull as
possible. This will reduce the reflection path differences.

BTW, the mod did cure the computer hash.
Mike
FM has what is called a "full quieting" effect. It would suggest that
your first signal levels were just barely above the level of full
quiet (and perhaps not even that good).

73's
Richard Clark, KB7QHC
Richard, after I read your letter I did a little better checking and
found
my signal is not weak it is to strong, I'm getting interference from
other frequencies.
Also I get stations on the wrong frequency.
I went out and collapsed the antenna to minimum about 1/3 of what it
was and
my problem station is perfect and the other station I listen to is
still good. The local
NPR station isn't good though. But I can download the podcast of
Science Friday :-)
Thanks, Mike
The usual, lousy FM tuner. They don't make'em like they used to. It's
the same with television sets, one large signal and they fall off the
rocker.

If you have a radio with a signal strength meter you could notch out a
strong station. But that only works it it's just one and far away from
the NPR frequency. The only other options are to get a better radio, a
directional antenna, or just live with it and use the podcast.

--
Regards, Joerg
This morning I got on the boat and the signal that was improved to good
by
shortening the antenna is now bad. 94.5 has interference from 101.1.
Oh well!


You really need a better quality radio and with radios and a lot of other
stuff older = better :-)

I mean, considering what the boat must have cost ...

Well the boat is a pontoon boat (maybe $6,000) that I run my business
from, my wife or I are on the boat 70 hrs a week.
The radio was fine when I used the original AC cord antenna, except when I
was on my laptop, it caused hash
in the audio. That's why I isolated the antenna from the AC, that did
eliminate the computer hash.
I have put together a car radio and wall wart that I use with a pillow
speaker at night. Maybe later I'll put
together another one for the boat.
Mike