Hello all. I have a Sears Roadtalker 934.38270700 base/mobile unit. Everything works except for squelch while on am. On sideband it works great. Ive cleaned all of the switches several times. I see some engraving on the back of the unit. D-3-4 D-6-9, and D-1-9. Do these make any sense to anybody. It confuses me as to why squelch works great on sideband, but not at all on am. Thanks for any help. :headbang