Some help please!!!!!!!

[dugansz]

I am new to this board and to HDTV. I bought my set about six months ago (panasonic 57"). I was in Best buy the other day and they had a demo unit STB Panasonic tudst51 for $300 dollars. I bought it just so I could get my feet wet and use it specifically for local network channels only since I have directtv satellite and this box won't work for that. It's an older receiver and it seems to work ok. The weird thing is that using the same antenna:
Connected straight to the tv (Radio Shack amplified rooftop antenna) I get NBC channel 15 very clearly. When I run the antenna thru the receiver STB first, a screen on my tv says:

Input signal found
Channel not available
Message blah blah blah

Does anyone that owns this stb or has owned it know what is going on. I get all the other available stations. This NBC station happens to be the only VHF format station of the bunch, could this have something to do with it?
Also, there is a switch on the back that says Native , 1080i,700p,480, etc. My ABC station won't come in unless I switch it from native to 1080i,700p. Is this because the station is being broadcast in this format? What does native mean? Is 700 p still hi def?

Thanks for any and all help. Jim

[57U]

ABC broadcasts in 720P. 720P is definitely High Definition. It's even been argued that it's superior to 1080i, although that's a subject for debate.

NBC, CBS and PBS are 1080i, while Fox is 480P, which is more like EDTV (Enhanced Definition) than HDTV.

The reason you may not be able to see ABC on your TV, without switching the STB is because your TV doesn't accept 720P. "Native" means the signal is passed through without upconversion to 1080i which all HDTVs can accept There are a lot of TV sets out there that cannot accept 720P.

Someone else will have to answer your antenna hookup question, since I am not well versed in OTA.

[DanB33]

I also have a Pana tudst51. The message you are getting --
Input signal found
Channel not available
means that the receiver in receiving a signal but it is not good enough for the receicer to decode.
Channel 15 is a UHF Channel and the VHF Channel needs a longer antenna. If you are trying to use a UHF antenna only it may be your problem.
I get the above message when the antenna rotor is moving. Grand Rapids has both UHF and VHF TV stations in several directions.
Try an indoor rabbit ear antenna for the VHF Station.
I hope this helps.
James Daniel Bishop