CB With cassette radio—help

Just acquired a 1981 with less than 36k original miles. It came original with the CB radio that has a cassette. The cassette player works fine, CB works fine, for the life of me I cannot figure out how to turn on the radio and get FM or AM stations. Anybody out there know how to turn this radio on?

Many Thanks

Does it look like this?  Found the image in a for sale ad for an '81.

Above the SEEK button the is a slide type switch that I'm guessing lets you select the stereo radio (RAD), the monaural radio (MON) or the CB (CB).

The "Mon" position allows you to monitor the selected CB frequency while listening to the AM/FM radio/tape. While listening to music(or whatever), any transmissions on the CB channel selected will mute the radio, and you'll hear the CB transmission. It's kinda kewl, but....it gets annoying after a while... 😬 😂

Ah, guess that makes sense.  Never experienced one of those units before so was just guessing on what MON stood for.

I had previously tried that but did not get any radio stations, static noise or anything at all. There has to be some trick to it. I bought a manual for the car but it tells you to reference the separate radio operation booklet that came with the car. Of course I do not have that one.

Almost, John...😃 He needs the manual for the radio with the UN5 CB option. 👍

My '76 did not have a radio when I acquired it. It did have the antenna, and the antenna wiring included a selector box with a switch. The switch options were CB or radio. Looks like the switch would have lived behind the driver seat maybe.  Mine was all coiled up under the rear carpet. Sorry I don't have pics, threw it away.

Is it as simple as just turning the volume knob out of the off position?

'76 did not have a CB option. What you have/had was most likely an aftermarket switching set-up to allow the factory radio antennae to also work for a CB antennae. I put one like that in my '74 so I could have a CB when I took it on our first long road tour years ago. I think it is still tucked up under the center console, now that I think about it! 😅