View Full Version : Cobra 29 LTD Classic issues

08-31-2016, 12:22 PM
I recently purchased a used Cobra 29 LTD Classic that is having issues with transmit. The radio receives fine but when I transmit the power meter on the radio does not move to the right. I have another radio sitting next to the Cobra that is on the same channel and I can hear myself talking but the modulation and clarity is terrible. I did find a broken resistor R53 and a burnt R56. The final looks fine but I have no way to test it. I've done some reading online that pointed toward maybe a bad IC3 or the final.

I'm very green when it comes to repairing a CB if you couldn't tell already. I like trying to fix things instead of going out and buying another radio.

Thanks for any help that anyone can offer.

08-31-2016, 10:43 PM
Have you checked the VSWR of your antenna?
And also have you placed the radio on a dummy load?
And have you turned the modulation up any? All of these things may be needed to get the radio to work like you want it to. If the modulation is set low from the factory that would explain a lot. Also a bad VSWR and/or match on your antenna system will do this. If you have the means to check the modulation, check the first. A simple SWR/power meter will help determine if you have much forward swing. If not, try turning the modulation up some to about 90-95%. This should help. It could also just be the meter itself that is not reasons correctly. Here are the VR's for the cobra 29 ltd classic.http://uploads.tapatalk-cdn.com/20160901/e0c70e5ab4a02f35118824bda8fed3f7.jpghttp://uploads.tapatalk-cdn.com/20160901/e0c70e5ab4a02f35118824bda8fed3f7.jpg
The info I've listed is from the site www.angelfire.com. This should help you get going. And use a 50 ohm dummy load rate for at least 20 or more watts to tune the radio and not your antenna. Also read about the other VR's and what they do. Hope this helps. Have a good one.

09-02-2016, 08:07 PM
Might just be a bad meter...

09-02-2016, 09:45 PM
He also stated the that the audio clarity is terrible as well. Might be feedback from having the receiving radio too close, but can't rule out other issues as well as a bad meter. Good suggestion though I will say, even though the radio was recently purchased as well as stated in the 1st post. Hope he gets it resolved. Lots of things it could be. He needs to trouble shoot things one thing at a time though. JMHO.

09-14-2016, 11:25 PM
I can't remember for sure I will repost if I am correct. Take out jumper 36 replace it with a 2200 up cap and in the same wholes on the other side of the pcb put a 66 ohm resistor that is a supper swingthing kit for the 29LTD classic you can also run two wires to a vr and have a dile a watt hope this helps o I almost forgot when you put the cap in put the neg side of it to the back of the radio or you will burn your finle if this doesn't fix the problem then it is ic3 and or your finle I hope this helps you good luck I just brought a couier 23 pulse back from the dead it's a good feeling

09-15-2016, 03:44 AM
Make sure you check your antenna system before doing anything else!! This is where I would look first. While your receive might be okay, with a bad VSWR or what most call SWR, your transmit may suffer drastically. This is JMHO.