Known issue with timers for off air recording.
If you turn to an off air channel and watch LIVE, everything is fine. If you set up a timer for later viewing, the recording is poor, if even watchable. What works as a stop gap is I record off air late at night so I turn the receiver to that channel and just turn the TV off but not the receiver. Then go to bed. Next day, the recorded show is fine because you were already "tuned" to that channel.
Performed some OTA timer test. I set up four timers in my Hopper 3 with a Dual-Tuner USB OTA Adapter and then put the Hopper in standby mode. After all recordings were complete I viewed each recording for approximately five minutes then went in to fast forward 15x speed mode. Viewed them all from my Hopper, then a 4kJ linked to the Hopper, and then watched them from another Hopper. Did not see any pixilation.
Also on another test, while watching live TV on an OTA channel I hit the record button and then changed to another channel. After the recording was complete I watched it and did not see any pixilation. Let me know if you need any more test with a different timer setup.
FOX 4:30 to 5PM Timer from Mini Guide
CBS 4:30 to 5PM Timer from Guide
NBC 5 to 5:30PM Timer from Mini Guide
ABC 5 to 5:30PM Timer from Guide
NBC 6:30 to 7PM Live TV, hit the record button