"Andy" wrote in message
...
Andy writes:

Most of the TV made in the last dozen years accept component
video signals as inputs, S-video , for example.

DTV converters put out Channel 3 analog and component video
analog....

VCRs accept component video inputs and put out component video
outputs...

... I really don't see the problem.....

If worse comes to worse, once can use an old VCR with a bad
transport to take in component video and put out channel 3 or 4.....
Bulky, but puts the old junk to good use...


Also, you can google " Digital TV encoder " , and find the
manufacturers
of the chips that do what you are talking about ---- taking analog
input
and making encoded DTV output...... I'm sure that those who make
the
chips have application circuits in their data sheets...

Andy in Eureka, Texas

That's fair enough Andy - given that we are UHF here in the UK rather than
VHF - but you miss the primary point of what I am saying. Already, LCD TV
sets are being sold, which have no facilities to receive analogue *RF*
signals. Yes, for sure, they can accept every other type of input known to
man, but not a simple, UHF, off-air analogue signal, as presumably, the
makers are thinking "no off-air analogue being broadcast, no need to be able
to receive any, then".

So yes, I could split the RGB or whatever output from the Sky box, and feed
it to more than one TV set, but with the best will in the world, it's not
going to be practical to feed it to many more TV sets. At the moment, the
output from my additional sources feeds into a trunked UHF distribution
system which I put in when I had the house built. There are at least 9
drop-offs in the main house that I can think of right now, plus a couple
more in my electronic repair shop area. My neighbour has a similar system,
and whilst that many drops on a trunked system is a bit unusual in a normal
house, I know many people who have three or four rooms fed from a multiway
UHF distribution amplifier located in their attic space, and fed, like my
system, with both off-air signals from their roof antenna, as well as output
from their Sky boxes and so on. I'm pretty sure that they probably don't
realise that when they replace any of the TV sets, they are not then going
to be able to 'receive' that additional content on the new TV.

So it's not a case of using the modulator in an old VCR. If it were that
easy, standalone modulators which take in AV and output a UHF PAL compatible
signal with sound, are readily available.

A number of ham ATV repeaters, both here and in the US, I believe, are now
running digital in tandem with analogue. Although many hams are using
ex-broadcast equipment to do the DTV signal construction from analogue
baseband inputs, I seem to recall reading that there are schematics around
for homebrew, presumably, as you say, using dedicated chips for the job. I
might try having a look down the homebrew route, and see what is around. In
the meantime, last night, I found what might be a suitable TV for my kitchen
which, as well as having the DTV receiver built in, along with every other
possible input also has - oh joy! - a bog standard UHF analogue tuner in it
....

Arfa