I have purchased close to 25 Samsung SIR-TS160 HD recievers for various restuarants. Several have had issues such as no sound but picture, or it can pickup satelite channels but not digital off-air. My most recent problem is that one of the recievers picks up sat. channels fine, but the local off-air digital channels go on and off at their own free will. This is a reciever issue, trust me. Has any one else had trouble with these?