VHF Feedback - The Hull Truth

Phillbo · 07-22-2002, 05:29 PM

When I key the mic I get a noise like feedback . It's still transmitting but is very anoying . Any suggestions ?
Could it be the mic or the antena ? I have tried wraping the mic in a towel and keying it but I still get the squeel....

Frank007 · 07-23-2002, 10:29 PM

How close is the antenna to the radio? Industry says to mount the antenna no closer than 3 feet to avoid feedback. Some radios work ok even if mounted closer so long as they are well-shielded.

You might try putting some aluminum (the thicker the better) between the radio and the antenna to see if that helps. If so, you could fashion some sort of shield (e.g., line your electronics box (if you have one) between the radio and the antenna.

Phillbo · 07-25-2002, 01:48 PM

Good call Frank but the radio is in the cabin and the antenna is mounted on the side of the boat about 9 feet away ..

I'm going to try a choke on the power line to see if that helps..

Could an external speaker be causing this ?

Booby Trap · 07-29-2002, 09:45 AM

Philbo,

The speaker is the problem and an easy fix.....just unplug it to trouble shoot the problem.....if the speaker is the culprit then mount it farther away from the radio (and the compass)....Booby

Chris J · 07-30-2002, 01:18 PM

If you are getting real audio feedback between the speaker and mike the radio is broken. Pressing the PTT switch on the mike is supposed to disconnect both the internal and external speaker.

On the other hand, if you have the volume set all the way to minimum and the mike wrapped in a towel and still get the squeal, you aren't dealing with audio feedback.

Right offhand I can't think of any installation issue that might account for this. If the voltage to the radio is OK, the problem occurs with the motor running and shut off, and all the connections (including grounds) look good, I'd say there is most likely an internal problem with the radio itself.