working on VHF radios

[waterinthefuel]

A few years ago I bought 3 old VHF radios on ebay. They now all have some issues and can't be used, even as a base radio. <br /><br />One has a very quiet transmit and receive. Any suggestions? Even powerful weather stations on high volume come in very low. Power supply is of good quality and putting out 13+ volts, even on 25w transmit.<br /><br />One has a loud buzz in the background on transmit. Any suggestions? This radio is very old and is about a foot deep and 3 inches thick, and weighs a good 10lbs.<br /><br />The other the LED screen went out, it's due to corrosion, I just have to try to fix that on my own. What about the others?

 

[JB]

Re: working on VHF radios

Technically, you are required by law to hold a FCC class 2 license to work on transmitting equipment over 5W.

 

[waterinthefuel]

Re: working on VHF radios

Oh well, I guess if I buy it 5th hand I'm going to fix it, or at least try to.

 

[Rock Hall]

Re: working on VHF radios

Water,<br /><br />When you say low transmit and receive, do you mean the signal is week, or the audio is very low?<br /><br />Also, do you know what the current capacity is on the power supply you are using? If it is less than 4 amps, try switching the humming radio to low power and see if hum is still there. That could also be a bad ground or short in the microphone or microphone cable.<br /><br />Mark

 

[waterinthefuel]

Re: working on VHF radios

Hey rock,<br /><br />The output of the quiet radio is 22 watts, and the power supply is capable of handling up to 7 amps continuous. The audio is very low. The mic on this radio is sad, it could quite possibly be the mic, but I wouldn't know how to check that. The mic cable has electrical tape on it, but that wouldn't explain the very low receive volume, would it? This radio is a Shakespere SE2001.<br /><br />The humming radio hums no matter the power setting. It actually transmits very poorly on low power. By that I mean on 1 watt the transmit light blinks, and the signal strength meter shows intermittent transmit signal, corresponding with the transmit light's blinking. That could all be the mic huh?

 

[waterinthefuel]

Re: working on VHF radios

Rock, I actually semi-repaired the quiet radio. I took it apart and noticed the tape ribbon wire between the front and back circuit boards had come loose on one end. I pressed it back in, put it back together and now its loud as all get-up on receive, but still quiet on transmit. However, I took the electrical tape off and noticed that the original mic has been cut off and the one it has isn't the original. I have a few other mic's I can try. It's back to working as well as it did before, but I'm seriously considering trying a different mic.