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From: ISW@cup.portal.com (Isaac S Wingfield)
Newsgroups: sci.electronics
Subject: Re: advice on descrambler
Message-ID: <19791@cup.portal.com>
Date: 22 Jun 89 22:05:01 GMT
References: <111377@sun.Eng.Sun.COM> <680@lopez.UUCP>
Distribution: usa
Organization: The Portal System (TM)
Lines: 21

Without going into too much detail (an exercise for the
student?), it's useful to note that *all* the sync signals
in NTSC TV are harmonically related - you can do the division
yourself, but from the color subcarrier at 3.579545 MHz, which
is available from the phase-locked oscillator in the set, you
can derive both HSync and VSync using digital divide chains.

You have to do a little manual cycle skipping to get things
lined up, but once it's locked, it's good for the evening...
(Don't ask me how I know).

Innocent question - they're sending that scrambled signal
uninvited into my house. Exactly why is it illegal to use
it for my own reasons? If they don't want me to have it. 
they can keep it out (some cable systems do just that, with
bandstop filters outside the house). I know it's not
nice to sell decoders, or kits, or plans, but exactly
why is it illegal for me to make use of signals within
the privacy of my own home?

Isaac    isw@cup.portal.com