yamaha cr-800

About  40 years old .

Thanks for your responses.  One last note, I get a station to tune in on the standard fm selection (no fm muting) and I still do not get the stereo or AFC/ Station lights to come on.  So I guess that is a confirmation that the signal and sound is mono and not stereo. 

FM Mute eliminates inter-station tuning noise and only allows strong and clear stations to emerge from the silent background.

It's possible that the muting doesn't work, or the switch is broken but the tuner will work fine in wide band mode so there's really no reason to fix it. 

The Yamaha most likely has a stronger muting threshold than your other receivers. Some tuners have adjustable muting. If interstation noise does not bother you when going up the dial then don’t sweat it!!

FM Mute eliminates inter-station tuning noise and only allows strong and clear stations to emerge from the silent background.

I'm guessing here, but I believe you need a better FM antenna. You should also use the 75 ohm input rather than the 300 ohm input if you have a choice. That works better for me. Depending on your location, you may even need an outdoor antenna designed for the 88 to 108 MHz. range.