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From: amigo@milton.u.washington.edu (The Friend)
Newsgroups: sci.electronics
Subject: types of scrambling
Keywords: sync modification
Message-ID: <1991May15.182554.12714@milton.u.washington.edu>
Date: 15 May 91 18:25:54 GMT
Organization: University of Washington
Lines: 18


     All scrambling entails (in TV use) is to modify the sync signal. If
the sync gets off-set enough from its normal position, it can't be tuned
in. Of the types out there, there seems to be only 3 major types:
gated sync, variable sync, and surpressed sync.
     Variable goes all over the place - in a sine-wave pattern 
(also affects audio since the sync passes through the audio channel).
 Surpressed doesn't contain enough (or none at all) sync for video-alignment
- so it must be recreated by timing clock in a descrambler. My guess with
gated is that it pulses off-set from where the sync should be, so that
video is off-set from where it should be. 
     What I'm wondering is how each looks in-use on TV? 

-- 
                                      ///
       Scott Rowin                   ///  amigo@milton.u.washington.edu
       ***********                  /// 
 - SPACE OPEN FOR LEASE -      \-\_///    Amigas really do it better...