Cobra vhf will transmit but sounds very muffled or weak. Sounds like I'm several feet away from mic. I receive fine. Just transmitting problems. I have already replaced mic

The static tells me that your audio chip is working, but the stages ahead of that are not feeding a signal to the audio amplifier. The intermittent receive sounds like a bad antenna connection, or bad contacts on your transmit - receive circuits. I don't know the Cobra 29 LXBT circuitry, but likely a relay is switching between transmit and receive when you press the mic key. You could try connecting your antenna to the pins on the relay that carry the rf signal to the receiver circuitry. If you suddenly starting picking up signals, you know the switch is the problem, as you have by passed the switch momentarily. Don't try to transmit in this condition.

Put SWR meter between your antenna and output, test wave length receive/transmit, might need a ground plane or center loaded stick.
Could be transceiver relay, try clicking mic fast, it should click out as fast as you key the mic.

Modulation being muffled could be the mic or it could be an adjustment in the unit.

sounds like somebody has tampered inside it , knocking out alignments. There is a resistor and very small transistor near back that controls transmit+receive. I don't know which number resistor it is on your model. I know where it is on Uniden/Cobra models(recommend Cobra 25ltd) Take to Cb shop or service repair place. They may help you. Just buy you a Cobra for cheaper and go with it.

make sure the mic is good. If for some reason the mic went bad, it will not receive or transmit.

As for the one with no receive, it most likely needs a new final.

If lightning hit your antron, it would be in pieces.

Sounds like its not wired up right, the audio wire must be off,take the plug apart and check the white wire, re-solder it. here is the wiring, pin1-shield,pin-2audio-(white), pin3-transmit-(red), pin4-receive-(black).....hope this was helpful...

If the receive works ok,sounds like a mic
problem,try another mic if you can find a
buddy who has a Cobra that may let you
try it most all Cobra mic will work but not all.
Good Luck

Hi and welcome to FixYa,

Which output is muffled, transmit (modulation audio) or receive audio?

If you are referring to the receive audio, initially, have you tried an external speaker? If it works good, then it would be an internal speaker problem; if not then others to check would be:

• IC1 - KIA7217AP audio IC;
• CM 10 & 15 - audio output capacitors 470uF / 16V.

if it were transmit / modulation audio, try replacing the mic.

Please postback updates.

Good luck and thank you for asking FixYa.

What happens if you "key up" and "let off" and the transmitter "hangs", you remove the microphone plug from the Cobra ?
Will it still be transmitting or will it stop ?
If it stops, the problem is in the microphone with a "hanging" switch which you can easily clean or replace.
Iif it keeps transmitting while the mike is disconnected, there is a problem with the Rx/Tx switching circuit. This needs further investigation by use of a circuit diagram.

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!