Re: Cable HD TV Systems

Private Citizen wrote:
>
> I heard somewhere that signals used for for HD TV are incompatibile
> with all existing TV sets.

Yes.  Existing television sets -- the kinds which have been around for
decades -- understand only analog (RS-170A NTSC standard) signals.

In order to receive ATSC (the standard which defines both standard-
definition and high-definition ("HD") digital television) via antenna,
you will have to:

(a) buy new television sets capable of handling ATSC signals, or:

(b) keep your existing television sets and buy set-top converters
which can change those digital (ATSC) over-the-air signals into
regular RS-170A NTSC analog.

> I also heard that there is a plan circulating to "transition" both
> broadcast and cable sytems over the next 5-10 years to 100% HD TV.

No.  The only transition plan presently in effect is one that requires
all analog over-the-air television signals in America to cease by 2006.

Cable system operators are not bound by that requirement, though.  They
will be free to continue offering analog signals over their systems for
as long as they desire.

Even if your local cable service does shut down its analog signals at
some point, then you could still rely upon the fact that their rental
descrambler boxes would offer analog outputs for older TVs.

The same applies to satellite service.  Their transmission systems are
already digital, and their receiver boxes already have analog outputs --
and will continue to have them.

> My questions. 1. Are any converter boxes on the market today capable
> of converting these signals to Standard Definition signals?
>
> STANDARD DEFINITION (SD) BROADCAST SYSTEMS
> may either be analog (NTSC / PAL / PAL-M / SECAM) or
> digital (DTV), having 625 or less scan lines and an aspect ratio of
> either 4:3 or 16:9. By 2006, most SD broadcasting will be digital.

I think you are being confused by terminology overload.  There are but
two kinds of television signals that you need to concern yourself with:
analog (NTSC), and digital (ATSC a.k.a. DTV).  "Standard definition"
(SDTV) and "high definition" (HDTV) are just relative terms describing
the amount of detail in either analog or digital signals.

So the question you really want to ask is: are there any converters on
the market capable of converting those signals to NTSC (analog).  The
answer is yes.  As I mentioned above, however, such converters are only
necessary for those who don't have cable or satellite service -- those
who will receive television strictly via antenna.  All existing digital
cable boxes and satellite receivers already have digital-to-analog
circuitry in them (as evidenced by the analog outputs that they offer).

> 2. Apparently the "over the air" broadcaters will join the "digital"
> age. Is it legal for me to attach such a device to my antenna, and
> cable, and continue to use the TVs I now own..

For antenna reception, yes, you will be able to purchase digital-to-
analog converters at most electronics stores and attach them legally.

For cable, things will work differently, and the answer is ultimately
dependant upon the style of cable service that you now have.

1.  If you have analog service without descrambler/converter boxes:
you will be able to continue receiving analog cable signals as you're
doing now for as long as your cable company provides them.  Again,
cable companies are not required to turn off their analog signals in
2006.  Your cable company may continue offering them until 2016, or
it may shut them down tomorrow.  Either way, at whatever point they
discontinue the analog channels on your system, you will receive a
notice from them informing you that you must begin renting their new
digital cable descrambler boxes.  For older television sets, those
boxes will have analog outputs on them.

2.  If you have analog service WITH descrambler boxes: same as above.
When they decide to shut down the analog signals in their system, you
will receive a notice telling you that your analog descrambler boxes
must be exchanged for new, digital ones (which, again, will provide
analog outputs).

3.  If you have digital cable service, then you already have digital
cable converter boxes with analog outputs on them.  In that case, the
point when your cable company shuts down its analog channels will be
irrelevant to you: your existing converters will continue working,
and you will be required to do nothing.