Hey, so I have a Sansui 7000 here want wanted to know what the normal behavior of the FM muting is with this unit, basically this one seems to not mute without an antenna, once an antenna is added FM muting works as it should, muting between stations. I've tried adjusting the muting threshold pot at the rear but it only affects how it mutes with an antenna. Don't have much experience with this model so I was wondering if that behavior is normal or not. FM stereo works as expected.