Cobra Cam 89 issue

[brownbomber72]

A guy gave me one the other day. It will key 5 watts and swing up to 15 but will not swing back down to 5 when I stop speaking into the mic. It stays stuck at 15 till I unkey the mic. What could cause this?

[2600]

A quick listen on another radio on the same channel while it's doing this may reveal that it has an audio feedback "squeal" when you stop talking. A radio that old is bound to have failing electrolytic capacitors in it. Some of them serve to keep signals from leaking between separate circuits. And if any of the audio from the modulator circuit leaks back into the mike circuit, you'll get a feedback squeal.

Would be my first guess, anyway.

73

[oldgeezer]

Buy a used 2010 year or newer Cobra 29 LTD and never look back.

[2600]

If memory serves, the CAM89 is a 23-channel base radio. That makes it 50 years old, more or less. The age issues you'll encounter in a radio that old call for what serves as an overhaul, more or less. Every electrolytic capacitor will need to be replaced because the chemistry inside that makes them work just deteriorates with age. Mileage is also a factor, so if the radio had a lot of hours on it there will be more of those capacitors failed than if it had not been used much.

Not so different from a 50 year-old car. Can't make it a daily driver with all original belts, hoses, tires, seals and gaskets. What makes those capacitors go bad has partly to do with the black rubber seal that holds the capacitor's chemistry sealed up inside. Rubber gets stiff and shrinks with age. This breaks the seal that it provided and that precious chemistry goes bad.

Feel free to ask around about 50 year-old electronic devices and you'll find this rule applies to more than just CB radios.

There is an online vendor called Klondike Mike who will sell you a complete kit of the capacitors needed for a lot of CB models. Don't know if the CAM89 is one of them, but might be worth a look.

73

[bobcat4109]

Looks like he does.... and I can tell you ... KM is a straight shooter.   Great place to get your caps.
I looked at the kit and there are not too many.


klondikemikescapkits.com/products/cobra-cam-89-electrolytic-capacitor-kit?_pos=1&_psq=Cobra+Cam&_ss=e&_v=1.0