cobra 29 help

[farmer]

I was given an old cobra 29 and when I hooked it up I could transmit but not receive. i tried with an external speaker and still nothing. the meter doesn't work so i can't use that to tell if its receiving and not working making sounds or not even receiving.
also there is a knob wired in on the inside of the radio, electrical taped in. what is it?

[4x4junkie]

also there is a knob wired in on the inside of the radio, electrical taped in. what is it?

Couldn't even begin to tell you without at the very minimum a pic of where it's wired into the radio... Maybe it's a power output control (Dial-A-Watt), maybe a talkback volume, could be a control for a noisemaker of some sort, could be anything really (it's not something that was there originally).

Do you have any CB or 2-way radio shops in your area? I would think someone there could help you figure out what's wrong with it (maybe repairing the radio's receive circuit if necessary).