Broadcast Issues


Nov 1, 2013
Nashville, Indiana
Currently have a Motorola CM300 mobile radio in our bay with the rear audio pins hooked to a large ceiling mounted speaker.

In order to broadcast our radio frequencies I used an old aux cable and wired one end into the speaker wires, I then plugged in to the computer mic imput. Other than a slight hum on the scanner app, it has worked fine. Until a few days ago it stopped.

After investigation I found the aux cord was burnt and fell apart. The radio no longer had any sound output and when I keyed the radio, it now goes to channel 0 and all the lights on the display flash on and off. Pretty sure it's fried.

What could have happened? Was there too much wattage going to the computer?
Does anyone have a suggestion how to remedy the problem? I have already replaced the radio and not hooked it back to the computer.

Any positive feedback would be appreciated. Thanks


I ♥ Ø
Jul 27, 2005
What pins did you connect to on the rear connector?

If you used the speaker output, and the cable grounded one side of the speaker leads, then you likely toasted the audio amp. The two speaker leads are 'floating' and cannot be grounded.

If it wasn't that (the "aux cord was burnt and fell apart") concerns me. There wouldn't be enough output from the audio amplifier to burn a cord. That suggests that it took a nearby lightning strike, some outside voltage made it into the radio or computer, or something else failed.