Guide :Radio Communications : 29 WX NW ST 40-Channels Base CB Radio
Loose tuning screw?
Unit is mounted in my big truck.
Pulled it out one day and heard a rattle. Opened the bottom and found one of those tuning screws floating around. (looks like a set screw, goes in one of the threaded tubes with the copper wire windings around it.) There are two hollow tubes without screws that I can see. A black one at the back left, and a brown one at the back center next to where the antenna hooks up through the back panel.
Seams like people can hear me for a good distance, but I lose them at 1/4 mile or less.
Also, the two empty tubes and the screw have no sign of the thread locking wax