"chuck" wrote

Along the lines Bruce suggested, it
might be worthwhile identifying the
transmission mechanism of the noise. It
may be radiated and picked up by the
radio antenna, or it may be carried over
the 12 VDC power wires.

The simplest test is to short the
antenna terminals at the radio if you
can. To see if the noise is being
carried by the 12 VDC wires, try using a
portable radio (with its own batteries)
in the same spot.

The portable radio test should be easy - I THINK we have one somewhere! The
AM/FM antenna is just an automotive type installed horizontally in a
locker - Is it OK to short the connection plug (RCA type). The noise is
acros the whole AM band but does not occur on FM - would this indicate it is
more likely radiated noise?

Usually, it is much easier to clean up
the 12 VDC power system (at least at the
radio connection).


Thanks for the input