"http://CBC.am/" wrote:

Where are the DX hdtv recivers?

HD signals do propagate outside their intended markets, to the delight of
DXers.
Yet no one has created a ASTC DX reciver.

To verify DX, all you need is some slow speed data -- and maybe some CC
captions.

There is no slow speed data in an ATSC signal. Verifying that an
8VSB/ATSC signal is present is easy: just look for the carrier
at the assigned frequency. This differs from an NTSC signal
in teh same channel. You could also use an autocorrelator and
look for the 511 bit PN sequence. But there is no way to do anything
more without getting the whole bitstream.

Doug McDonald