[HATS] Do we need DHTV?

[Ed Manuel (N5EM)]

At 09:28 AM 2/1/01 +0100, you wrote:
>Preliminary remark:
>------------------
>I send also this text to some EATWG (European Amateur
>Television
>Working Group) guys in order to try to "import" them in the
>DHTV list (subscribe to dhtv@yahoogroups.com) and in this
>discussion.
>michel hb9afo

I will not repeat Michel's lengthly analysis of the current state of DHTV 
nor his opinion of what should be the future of DHTV.  Thanks for your 
comments and ideas, Michel.

It's certainly true that DHTV does not seem to be ready for amateur prime 
time.  The continued very high cost of state of the art encoders makes any 
real experimentation just that - experimentation that might or might not 
lead to some deployable form of DHTV.

I still believe there is reason to pursue this in amateur circles.  There 
are those who believe that fast scan ATV must not give up anything to 
quality if DHTV is adopted.  I believe you have to give something to get 
something.  The thing we would all like to get is more space to play with 
ATV.  Right now, there is a whole bunch (a Texas measurement) of pressure 
on the spectrum we use for ATV.  I, for one, would like more channels to 
play with.  Since our only option to getting more channels today is to move 
up in frequency (and we're already using everything up to 2.4 ghz. - so 
that means UP from there) I would welcome a digital option that might let 
us carve up one of those 6 mhz. VSB channels into two or three digital 
channels.  Would I settle for the equivalent of a 128 kbps video 
conference?  No way.  But would I accept some limited pixelation to get 
those additional channels?  Show me - I'd love to have that choice.

There are a number of different ATV users in the hobby.  There are those 
who love chasing ATV DX - for them, VSB AM is perfect (using big, black, 
block letters).  There are those who like to use a local repeater and send 
high quality pictures to each other.  There are those using ATV for public 
service work.  DHTV can fit into some of these areas and provide some benefits.

I would welcome suggestions about available hardware that might be 
used.  Demodulation is pretty easy right now.  It's the ability to encode 
and generate the stream that is the problem.  HATS (Houston Amateur 
Television Society, Inc.) continues to look for fertile area to do 
work.  We have a small amount of money to invest in the development of 
DHTV.  If a piece of dedicated user hardware needed to be constructed to 
make it fly, HATS would consider the possibility.

My personal goal has been to be able to generate a "nearly" perfect fast 
scan quality picture with an occupied bandwidth of 2 mhz.  And, before you 
say that is not possible, we are already doing stuff we thought impossible 
just a few years back.  It's just a matter of getting access to the 
technology that is already out there on the leading edge.  Imagine what 
that would do for you on the 70 cm band.

DHTV has been moving very slow - but then the visionaries who started this 
list were way ahead of their time.  We can do it, we need to do it, and we 
will do it.  Who will bring the idea that makes it happen forward?

Ed Manuel, N5EM
Houston Amateur Television Society, Inc.
n5em@amsat.org

---
Send e-mail to 'listar@stevens.com' with subject:

  'unsubscribe hats'  to unsubscribe from this list
  'subscribe hats'    to subscribe from this list
  'help'              for more information