>> Why doesn't anybody just make a component -> 8VSB
>> modulator (like an RF modulator
>> for composite video, only up-sized)
>> so that we could record ANY HD signal with a hipix?
Aside from politics, there are a few (major) practical problems.
The component outputs are high bandwidth uncompressed
analog outputs, so you would need very expensive
"signal capture" hardware to get the HD back into
a digital form. Then you would need a very expensive
HD MPEG2 encoder to re-encode it. Then you would need
the elusive 8VSB modulator to put an ATSC wrapper on
the MPEG2 and broadcast it as an RF signal.
Even with all that you would have reduced the picture
quality by doing digital -> analog -> digital.
I wonder if there might be some high end commercial
products that are designed to (for instance) let
someone distribute HDnet on a cable system or to
an apartment complex? Like something from Drake?
http://www.rldrake.com/digital/index.html
>> what exactly is an 8VSB stream?
>> Is it mpeg-2? Is it some kind of digital
>> representation of analog?
8VSB suggests that it is an ATSC datastream
which has been "modulated" for RF broadcast
on the OTA frequency spectrum. The Dish modulators
output the ATSC stream as an 8VSB signal on chan 3 or 4.
(there were some early prototype dish modulators which
did UHF like chan 14 or something).
The ATSC datastream is a 188 byte packet format which
can pass along multiple MPEG2 datastreams (video and
audio) as well as data broadcasts, program guide info
and things like that.