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Path: utzoo!watmath!jmsellens
From: jmsellens@watmath.UUCP (John M Sellens)
Newsgroups: net.video
Subject: A Question on Cable Converters and Converting in 2 Directions
Message-ID: <8634@watmath.UUCP>
Date: Mon, 13-Aug-84 13:09:26 EDT
Article-I.D.: watmath.8634
Posted: Mon Aug 13 13:09:26 1984
Date-Received: Tue, 14-Aug-84 01:16:47 EDT
Organization: U of Waterloo, Ontario
Lines: 43

This query has its roots in pay TV, but has nothing to do with
unauthorized reception etc.....

Up here in Canada, pay TV is an extra service that you pay for on top
of your regular cable TV charge (which I understand may not be the case
in (some parts of) the US).  The pay staions are on converter channels
(i.e. not ordinary UHF or VHF frequencies).  You must set up your
magic boxes as follows:

   -----> converter -----> decoder ----> TV

which makes it hard to use your TV's built-in cable converter (since you
always have to keep it on channel 3 or 4).

My question is: how hard would it be to make a small box that strips one
channel out of the incoming signal for input to the decoder, then takes
the output from the decoder and splices it back in to the other signals:

-----> split ----all channels except the pay channel-> join ------> TV
         |                                              ^
     pay channel only                                   |
     converted to ch 3                                  |
         |                                              |
         ----------------> decoder ----------------------

Notes: decoder expects one channel coming in on channel 3.
       the 'join' would take a signal on channel 3 and move it
           back where it started (e.g. 26)
       the 'split' removes the scrambled 26 from all the other
          channels, converts it to channel 3, and sends it to the
          decoder.

I envisage a small little box, with some (possibly inconvenient)
way of setting the channel that you want to decode.  Of course this
whole idea falls apart when we start talking about more than one 
channel.

Any comments??   Thanks!

John M Sellens
UUCP:  {decvax|utzoo|ihnp4|allegra|clyde}!watmath!jmsellens
CSNET: jmsellens%watmath@waterloo.csnet
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