No transmit or recieve

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

common problem bad solder joints in the vco circuit take it to a PROFESSIONAL

try your mic

Its just RF feed back, that's normal, try to re-route the coax, or just turn the FM down, o try turning your modulation down....hope this was helpful....

Hi Darrel,

Since you didn't say if you have ever used this radio successfully before, I have to assume it is "new to you" and that you have never seen it work or used one like it before. Start with a few basic settings below:

Turn Squelch to minimum.
Set RF Gain (if present) to maximum
Set Mode to AM or FM
Set volume to 1/3 up
Connect to 50 ohm dummy load.

Turn power on. Hopefully you hear static. If not, try SSB or FM. Still nothing? Try connecting to an external speaker.

Chnage back to AM or FM mode. Key mic check & for transmit indicator. If none, change mic or manually short the PTT contacts in the mic or at the radio to see if it can be made to xmit.

If no xmit - insert SWR meter between xmitter and dummy load. Try to xmit on AM or FM again while watching SWR forward power, if none indicated, xmitter is probably defective.

Replacing parts in a xmitter is not recommended. You'll need an FCC license and a fair amount of expensive test equipment to test repairs, set power levels and deviation and perform an alignment to be sure you aren't causing interference on other frequencies and bands.

You'd be better off bringing it to a radio repair shop for repairs and an alignment.

Check the wiring on the mic plug sounds like you have a loose wire or one thats about to break off.Good luck.....Dan

it is probalby busted mic on the unit. could happen if you dropped it.

make sure your s/rf switch is in the right place on the radio is the most common problem i have found

Hello Darren, Yes it sounds like the mic is wired bass ackwards,,! A cobra 25 mic wiring is
PIN #1- Shield or ground wire
PIN#2- Audio or Transmit modulation
PIN #3- Transmit or Dead Key
PIN #4- Receive Audio.
When your keying the mic, the RX wires are being connected to make the RX work,,,
*** Let me know how you get along with it. Either buy a new mic wired for your radio or you or someone comfortable with soldering needs to resolder the correct wires back on the mic plug,,,Like I said, let me know and have a great day,, Mechanic is back quiet!

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.