I wouldn't over think it too much. Try just a floppy wire 18 inches or so,
and see what noise it picks up? You're bigger problem is those radios
aren't designed to pick up distant stations, so outside of a large metro
area you might not get any reception, or worse a signal that constantly
fades in and out. Try the simplest solution first, then start adding
pieces.

Robert N3LGC

"Ken C" wrote in message
...
On Fri, 17 Feb 2006 04:27:04 GMT, "SignalFerret"
wrote:

The shield on the headphone cable is used as the antenna for such devices.
As for matching, how good of a match can a headphone cable be? Inside
most
radios the connection is a single cap, in the pF range, between the jack
and
the RF front end.

Hmm. Well, the shield on the shielded stereo cable between the player
and the helmet sound module might pick up some interference from the
motorcycle's electrics. What components would you suggest that I
install on that cable to filter that out? Basically, I would want to
filter out everything that is not audio frequency (20 Hz - 20 kHz) or
between 88-108 MHz.

The player headphones have a main cable that is 29" long before
splitting to each headphobne. This is 1/4 wave for FM BCB. I could,
as you suggest, splice in a 29" wire at the player end of the cable.

Ken KC2JDY