GROUNDING RADIO

[PATRICK]

I JUST PURCHASED A NEW MARINE RADIO TO REPLACE THE PREVIOUS OWNERS "NEW RADIO" JUST INSTALLED. ITS A MARINE MODEL FROM JENSEN.NOW THE OLD RADIO LOOKED OK BUT HAD SOME ELECTROLISIS ON THE METAL CASE. WHEN I RAN NEW WIRE TO IT AND THE BATTERY I GOT A RHYTHMIC NOISE AND A DEAFINNING SQUEEL. WHEN I USED TO INSTAL NEG. GROUNDED RADIOS IN MY CARS, THE GROUND WAS ACCOMPLISHED WHEN I RAN THE METAL BOLTS INTO THE METAL HOUSING AND THE SHEETMETAL ON THE CAR. HOW IS THIS ACCOMPLISHED IN A PLASTIC BOAT?I HAD A GUY SUGGEST RUNNING A GROUNDING WIRE INTO THE WATER OVER THE SIDE. AND HOW WOULD I TEST RADIO TO SEE IF IT WORKS WHILE ON THE TRAILER IN MY DRIVEWAY? ANY HELP FROM THE EXPERTS WOULD BE APPRECIATED. THANX PATRICK.

 

[Steve Paul]

Negative case ground

A negative case ground wire back to the battery negative or negative bus if you have a distribution panel should do just fine. A # 10 or 12 strnded copper will suffice. I don't know if the corrosion was from moisture or electrolysis, but I suspect moisture in this case (no pun intented). Try a little electric silicone grease or plumbers silicone to cover the connection to the case. Is this a negative ground radio? Some can be either just look at directions.

 

[Ramblin' Rod - Mac 26D - SeaQuell]

The "GUY" didn't have a clue!

As mentioned by the previous responder, most automotive or marine stereos have a negative chassis ground.Connecting the chassis and negative power wire to the negative battery terminal, is the only "ground" required.Beware of the speaker wires. Many "high powered" units, have "floating" outputs. You cannot tie the negative speaker terminal to negative of the power source. If you output more than 8 watts per channel this is likely the case.As for the rythmic noise and high pitched squeal of the old unit...that doesn't sound healthy. If it was wired correctly when it did this, I'd recommend pitching it.

 

[Ray]

Negative Ground

Patrick, Think of it this way. Your boat in the water and the fiberglass is the insulator. Your car on ground and the rubber tires are the insulator. Either way you have no direct ground to earth hence you use the negative side of battery as ground. I too have an older Mac 26X 1997. Radio is old also but works a little. Bought handheld model two way radio I can keep in cockpit as this is more convenient.

 

[Steve Paul]

Good luck on that over the side wire

If Patrick isn't an electronic's person the the word "ground" is getting in his way. These are old phrases when cat whisker radios were alive. Think of the "hot" wire as + positive and the "ground" wire as - negative. In order for anything to work all the negatives must be connected together and the positives connected to the + terminals on the gear whatever that is. Earth ground is not important here. In order to use the 12 volt power here there must be a return path to the battery. Suggest you read up on beginning electricity or take a class or talk to a knowledgeable person. The guy wanting to hang a wire over the side must be kidding or absolutly the wrong person for this job. LOL when I read that. It's really very simple so don't despair just go slowly.Good luck,Steve