Is My TV's OTA Tuner Crap?

I'm gonna repeat myself here, because I believe I am correct. Yes, you can combine a regular Sat. line with an OTA line. But I don't think you can combine OTA with the MODULATED TV2 output, which is what you are trying to do.

You can and I do, it just takes a lot of trial and error to get working clearly.

Is the diplexer crap? All the amps and diplexer are from Radio Trash.

Use a combiner, a diplexer is for something else.
 
The modulated TV out from the 942/622/etc can (and should?) be combined with you OTA antenna's signal using and plain old SPLITTER. Don't use a diplexer. I have my OTA amplified to my home run panel in the basement. It's then split in two for the run to my 622 for HD and to feed into the splitter (in reverse) that combines with the modulated output from my 622. Picture quality is fine on all my home run distributed tvs (4 of them). To watch tv i just have the RG6 cable plugged directly into the "other" tvs and tune to the ota channel or to my channel 56 or 60 (modulated channels for tv1 and tv2 that i chose).

I do have a cheap radio crap amplied splitter at my distribution panel that is amplifiing the combined signals.
 
Thanks splat10...simple, yet effective. It works like a charm with a standard splitter. Lesson learned - go back to basics.
 
If you have an old VCR, hook line from 622 to ant. in tune VCR to the ch sent to TV 2.
Hook up A/V cable (yellow,red and white) on VCR to A/V in on TV.
Now run ant. to ant in on TV
 

DISHCOMM capable receivers?

using directv dish for dishnet