Maycom EM-27 Transmit noise

You check your radio with other radio very near. If radio is hearing your transmission then it mean that your Radio Power Module not working if very near radio not listening you then your preamplifier and Power amplifier is not working, it mean your Radio Transmitter faulty, only Receiver is working, you consult with any Radio Service shop. One other thing if you have software also check Tx/Rx frequency it must be same for simplex operation.

this is strange as most times if a proper transmit key is depressed , then the radio switches from receive to transmit , the mfg know this would cause some great squeal from receiver /transmitting so close to a receiver so the part that is the receiver is muted to keep this from happening , id say there is some fault in the part that does this muting of receiver

sounds like a repair for a tech to me.

CB radios and hand-held CB radios can operate on the same channel and be in contact with each other. Other hand-held radios do not operate on the same frequencies and even though they may have channel numbers the channels have different frequencies and will not operate to CB radios.

It sounds like the mic either has a problem, or its wired incorrectly for that radio.

Try a new mic, and make sure it's wired for that radio.

Also, if you have talk back then it's too loud, or your mic gain is too high.

The type of radio would help me know weather or not it could be the mic wiring.

when you had it modded there may be a cold solder joint. So when you tap it, it starts working

Try replacing TR41 (2SA473).
Also check TR40 (2SC945), D78 (7.5 volt Zener Diode), and D79 (KB 262).
[email protected]

Yes, the wiring is different. Reverse the wires on pins 1 & 2, then reverse the wires on pins 3 & 4.

The wiring for you radio's mike is:

1- Audio
2-Ground (Shield)
3-Receive
4-Transmit

Depending on the vintage of your mike, the colors Uniden uses for these functions are white or yellow for audio, red is transmit & black is receive.

throw that annoying noise maker away