Newsgroups: rec.video

In rec.video, an660@cleveland.Freenet.Edu (Sandy Maurer) writes:

> 
> All this talk on rec.satellite on SVHS vs composite video is
> confusing to me. Its important to me in that Im still trying
> to figure out which IRD to buy...one with the SVHS or w/o.
> There is only one IRD with this feature however.
> 
> The consenus I believe that SVHS from satellite is just composite
> video so stnrd SVHS connect would yield no gain....unlike an LD
> player. What am I missing here?
> 
> Would the purchase of the SVHS output IRD be for nought?
> 
> 
> Sandy
> 
> 

This basenote will probably be flooded with answers (if not already) so 
I'll try to be brief...

First it is S-Video (or Y/C) NOT SVHS signals. Y/C is the NTSC components
of luminance and chrominance seperated.

Luminance + Chrominance = Composite NTSC

All NTSC signals (that I know of) from Satellite, LaserDisc, Broadcast, 
and Cable are COMPOSITE signals.  Signals (internally sometimes) from 
VHS, SVHS, 8mm, Hi8, Beta, and most other consumer TAPE formats are S-Video
because the two components are stored seperately (by modulation not
physically) on the tape. (Losses/interference can & do occur when these
formats combine the signals to create a composite output. Here is where the
advantage of using S-Video lies.)

You would gain NOTHING from using a S-Video connector from a LD player or 
Satellite IRD except if the Y/C seperator in the IRD or LDP is better than
the built in seperator in your television.

You can also get up to the full NTSC allowable resolution with BOTH composite 
and S-Video (dependant on media ~425 lines). A modulated (braodcast or cable) 
signal has a maximum horizontal resolution of 350 lines. I am not sure
about satellite but I think it is greater than 350 lines (dependant on source).

KEY:   ******** COMPOSITE    ========== S-Video   XXXXXX Modulated (ch 3/4)

+------------------------+                   +------------------------+
| LD/IRD      (internal) |     GOOD SETUP    | TELEVISION  (internal) |
+--------+               |                   +----------+   +---------+
| Media *|***************|*******************| RECEIVER |===| DISPLAY |
+--------+   +-----------+                   +----------+   +---------+
|            | Seperator |                   |                        |
+------------------------+                   +------------------------+

+------------------------+                   +------------------------+
| VCR         (internal) |     GOOD SETUP    | TELEVISION  (internal) |
+            +-----------|                   +----------+   +---------+
|            | Combiner  |                   | RECEIVER |   | DISPLAY |
+--------+   +-----------+                   +----------+   +---------+
| Media =|===============|===================|==================A     |
+------------------------+                   +------------------------+

+------------------------+                   +------------------------+
| LD/IRD      (internal) |     BAD? SETUP    | TELEVISION  (internal) |
+--------+               |                   +----------+   +---------+
| Media *|*******V       |                   | RECEIVER |   | DISPLAY |
+--------+   +-----------+                   +----------+   +---------+
|            | Seperator |===================|==================A     |
+------------------------+                   +------------------------+

+------------------------+                   +------------------------+
| VCR         (internal) |      BAD SETUP    | TELEVISION  (internal) |
+            +-----------|                   +----------+   +---------+
|            | Combiner  |*******************| RECEIVER |===| DISPLAY |
+--------+   +-----------+                   +----------+   +---------+
| Media =|========A      |                   |                        |
+------------------------+                   +------------------------+

+------------------------+                   +------------------------+
| VCR         (internal) |    WORST SETUP    | TELEVISION  (internal) |
+            +-----------|                   +----------+   +---------+
|            | Combiner  |XXXXXXXXXXXXXXXXXXX| RECEIVER |===| DISPLAY |
+--------+   +-----------+                   +----------+   +---------+
| Media =|========A      |                   |                        |
+------------------------+                   +------------------------+

Well so much for being brief. I hope that this answers the questions.

- Matt Nieberger

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mattn@FC.HP.COM

The opinions expressed are mine alone and do not
necessarily reflect those of my employer.
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