Cobra 29 LX...LCD screen model

Adjust the RF gain knob?

 

Sounds like a bad connection with the coax if the RF Gain is turned all the way up...I would first check at the antenna, then check at the back of the radio...It could be screwed in all the way, and still have a connector shorted out...Doubt it's the radio, I have two of these 29's and never had any kind of problem out of them.

You can do a "Radio Check" on that radio by going into the menu and scrolling down to "Radio Check" and it will tell you if the antenna is bad (or coax) It will say "FAIL" if there's a antenna problem. (This is where you would be checking your SWR, and if it says FAIL, then your SWR is high, but it could be caused by a coax connector, or pinched coax, cracked or broke antenna...)

I would check this first before buying another radio.

 

You might have killed the radio by not adjusting your SWR/checking the antenna. When you press the PTT on the mic, the cb transmits power to the antenna to broadcast your voice. Since it didn't have a proper outlet for that energy, it sent that power back into the radio possibly overloading the circuits inside(think turning on a water hose then pinching it to create pressure). That's my diagnosis from the info given.

I take it you didn't read the owner's manual, right?

 

I'd suggest to get the radio tested at a cb shop to find out if it still works(transmit/receive). The coax in the truck is probably bad if you got the antenna failure from the very beginning.

 

Depending on the model of truck, to coax might be bad due to it being bent all the time at the door hinge point. If your antenna is mounted on the mirror bracket and the mirror is mounted on the door and moves when you open and close the door then your coax is being contantly bent each and every time the door opens. This is real bad for coax.

If the radio said you had bad swr or it failed the swr test then you should have had someone look at the coax and antenna before operating the radio. Only being able to transmit or hear 1 or 1 1/2 miles is not good. If everything is in working order then you should have easily been able to hear and transmit out to 8-10 miles.

If you want a radio to live then you have to have proper coax. 50 ohm coax for a single antenna or two 75 ohm coax for dual antennas. You can not use a single antenna on a cophased or dual antenna coax.

The antenna bracket has to be properly grounded.

Make sure the antenna itself is not grounded. There is a plastic washer on the antenna bracket that isolates the antenna from being grounded.

A decent antenna that is not damaged. I see too many fiberglass antennas that are damaged and the user had no clue.