[stipakb]

I just installed a new Uniden UM625c VHF radio. Even after I set the squelch to stop background noise, there remains a slight amount of noise coming from the speaker.

This seems wrong. The older VHF radios I have owned have not done this; the speaker was completely quiet when the squelch was set above the background noise level, unless there was a transmission.

The old VHF radio that I replaced did not have any speaker noise like this, and I am using the same antenna and power connections. The only thing different about the installation is that it was easier to leave the old in-line fuse in so I have two in-line fuses, but I don't think that could explain the noise.

What could be causing this low level of speaker noise, even when the squelch is set above the background noise level?

Brian Stipak
Portland, Oregon

 

[windward54]

A little more info might help. What kind of noise is it? For example, I get a humming noise on my VHF when at the dock (inverter interference). Other systems on a boat can cause interference as well, especially ones with electric motors (refrigerators for example). Try turning off other systems on your boat one at a time until you eliminate this cause. Just turn the circuit breaker off while listening to the radio. Finally, land-based radio systems can cause issues as well. Our local water utility system uses a radio-based system to send and receive information and control equipment. Every once in a while I get a little interference from their sites. Plus signals bounce all around from other boats. So the question is for that one is do you get the same interference out on the water as you do at the dock?

 

[k1vsk]

Another simple trick is disconnect the antenna - that will tell you if it is radiated noise. The only two other possibilities are conducted noise or internal noise. Obviously if disconnecting the antenna works, it is radiated noise. Conducted noise can be eliminated by following Windward's suggestions above. Once you eliminated those two, the only other source is the radio itself.

 

[jarcher]

I have a Uniden VHF that does the same thing. I bought it because it was relatively inexpensive and well reviewed, but I see I got what I paid for. The radio works well enough but I have the same noise you describe when it is supposed to be silent.

We can't hear it up on deck, since the radio is below. We're mostly on deck, but when we're below it is annoying.

 

[GeorgeB]

You might want to put on a ferrite choke on you antenna cable as it enters into the radio. This one is from Radio Shack and is under six bucks. I find that ferrites also work on clearing up interference on stereo speakers and even digital devices.