Doug,
Given your previous posts on this group I'm a little surprised you
haven't heard of or seen these before. The power filters I'm talking
about are also called noise filters. They connect to the power lines
going to the boat electronics to filter out problems caused by other
equipment. This could be other electronics like maybe using the chart
plotter interferes with use of the VHF. Or you might get noise from the
engine ignition system or alternator. Maybe running your windshield
wipers wipes out your VHF so you can't talk and look through the
windshield at the same time. There are also filters for this equipment
too in order to keep the noise coming out of these from getting into the
system in the first place. You can check online at the Newmar company
site for examples. They run from around $70 per instrument up to
hundreds or even a thousand each dollars depending on what system you
choose.

Bruce,
In the past you have posted here about all your experience in
electronics repair. I am confident that you knew what I was asking.
After all, I just asked a couple of questions in order to get the
opinion of others who would hopefully share their collective knowledge.
I don't know why this ****ed you off so much but if you don't want to
play nice please feel free not to play at all.

Earl