My mom's wagon when I was a kid had this option. The three-position selector switch in the upper right side - where it shows "RAD . . . CB" stands for functions RADIO / Monitor / CB. So when the switch is all the way left, it is in RADIO only mode, when the switch is all the way to the right it is in the CB mode and the middle position is called MONITOR where you can listen to the radio and if there is any transmission on the selected CB channel, the radio cuts off and the CB cuts in immediately and then goes back to radio.
I had a ‘78 Coupe deVille with the fancier version-it had the 8 track and a digital tuner display. Patrick
Yes. It was a power antenna that had a signal splitter combined in the coax. Part of the signal went to the am-fm radio and part to the CB. Not very efficient to be truthful.
I had one of the under dash Buick accessory ones with the Trishield used prior to the above one, I had searched for years for one and finally found a beauty. It was then lost in the garage fire.