Optimus STAV-3690 - Manual (Page 18)

18
Basic Operation
Using FM MONO To receive FM stations in stereo, press FM MONO so MONO disappears from the
display. STEREO appears when the tuner receives an FM broadcast in stereo.
You can improve the reception of weak FM stations by pressing FM MONO so
MONO appears. This reduces noise while you listen to a weak FM station, but
you get monaural instead of stereo sound.