Kenwood TM-742a problem

[nick1169]

I recently recived this kenwood unit and the problem that I am having is there is no voice in the TX. SWR and power output is good just nothing to be heard on the other end but a dead key. Any help would be great. Thanks in advance.

Nick

 

[nick1169]

I have also found that the keypad on the mic is not lighting up. And to clarify what i have above, the radio will tx but there is not modulation. Thanks again in advance for any help.

 

[remote1]

My first thought was that you burned something up from someone transmitting without an antenna connected, but now you say it will transmit -it may be your mic that is bad. The 642/742/942 Kenwoods were known to have the mic buttons go out. You can open it up and re-solder a new push to talk button or just replace the mic.
I have replaced several push to talk buttons in the last few years, it is simple if you have basic soldering skills.
You may want to borrow a friends mic first and try it and see if that is you problem.
Good luck, it a great radio don't just shelf it.

 

[scruffypatch]

FT-742A Audio Problem

Just bought a FT-742A with the same problem. Found that the 8 V DC (actually around 6 V on another 742 I have) that feeds the mic was missing. Opened the mic and found there was around 4 V for the key pad and the other mic functions on one of the other pins so I jumped that voltage over to the 8 V line. The lower voltage seems to work ok. You have to follow the color of the mic cord wires to find where they go. The 8 V line is suspose to be on pin 2 looking at the front of the plug in the 742.
Hope this helps.