My current 622 (my 4th) will not lock on a tower that shows a 92 signal strength, but locks fine on another one that shows around 94 sig - in the same general direction. I bought a new UHF antenna and preamp and replaced the coax. No difference. I bought a Samsung OTA HD receiver (DTB-H260F) for my DLP set and it works fine on both distant towers. It shows 10 bars signal (max) on one tower and 8-10 bars on the other one. The picture is perfect.
I also have an HDTV card in my PC and it works fine on both towers (with a total of 5 channels transmitted.) After conferring with the two station engineers and a Ph.D. electrical engr. friend, the conclusion is that SOME 622 OTA tuners have problems. Two likely problems are that they do not handle strong signals (poor dynamic range) well and/or don't handle multipath well. Among the tests, I put increasing attenuation in the coax line feeding the 622 until the 622 would lock on the problem station. I had to go all the way down to a signal of around 65 (from 92) to get the station to lock. There are clues in there alone for the the engrs.
I spent weeks swapping gear and documenting all this and forwarded it to some upper-level techs at Dish, one of whom is in the receiver division. My tests were conclusive beyond questioning, so I can only hope that Dish is looking into the design of the 622 OTA tuner. Many, many people report that their tuner in their HD set does better on OTA than the OTA tuner on the 622. Others say their 622 OTA tuner works great. I had 3 other 622s and an 811 that picked up both towers fine!
The Samsung DTB-H260F is a superior receiver, with HDMI, Composite, Toslink audio. I now run it into a Toshiba 37-inch HD monitor HDMI input just to pick up OTA. If the 622 is ever jammed up with 3 timers running, I flip over to the OTA setup and can watch Hi-Def live on NBC, CBS, FOX, CW and MyTv, even out here in the sticks. I used to run the H260F into a Composite input on my main DLP set, but when SEARs had a sale on the 37-inch Toshiba monitors, I could not resist.
MY OTA stations are in a different DMA from my HD LIL channels, so I can also do A-B comparisons of a network feed from satellite and from OTA at the same time - from two different network feeds. Dishquality appreciates the input that I can give them in this manner.
