Cobra 29 no modulation on transmitt

For discussions on CB Radio Repair and Troubleshooting, do not post modification requests here, use the Modifications forum !
Post Reply
StrightClaw
Light User
Light User
Posts: 105
Joined: Wednesday 31st May 2006, 6:25
Location: Remlap Alabama

Cobra 29 no modulation on transmitt

Post by StrightClaw »

I was talking on my 29 and out of no where the modulation just went out.Anyone know what I need to check?
Last edited by StrightClaw on Thursday 17th Apr 2008, 21:56, edited 1 time in total.
User avatar
Rick
Technical Helper
Technical Helper
Posts: 1041
Joined: Sunday 4th Jun 2006, 12:52
Location: UK

Re: Cobra 29 No TX modulation.

Post by Rick »

No TX audio: Use the checklist below.
1) Check the CB/PA switch, it may just be in the PA mode.
2) Check the mike by replacing it with a known good working one.
3) Check the PA and Ext speaker sockets for short to ground or open circuit.
3) Try doing a PA test. If the PA is not working you probable, have a bad audio chip.
4) If the PA is working, check around the audio transformer for cold solder joints and broken tracks and the RF spike diode.

The above applies to most radio which have a PA socket.
Rick.
StrightClaw
Light User
Light User
Posts: 105
Joined: Wednesday 31st May 2006, 6:25
Location: Remlap Alabama

Post by StrightClaw »

Rick I checked everything and hit the solder joints around everything and my tx modulation came back. You are the MAN Rick Thanks for your help.As always you had the answer Thanks Again!
Post Reply