[QuadList] TBC

[Chill315 at aol.com]

The RCA machine did use the servo to keep the video in the center of the  
TBC window.  Ampex did it a different way.  Thus I always found the  Ampex 
method easier to keep running.  The feed back loops in the RCA had  you 
scratching your head every now and then.
 
The reason that I would put the TBC after the AMTEC is that it does a  
flywheel type of correction when the machine is not H locked.  This is  the 
first step in the correction process.  To go later would be a potential  issue.  
The Colortec would be shut down in this mode.  The Proc Amp  would replace 
the sync.  Thus this is then the only spot that is easy to  grab with any 
certainty of working.  
 
The Merlin machine was based upon the upgrading of a VR-1100.  This  
originally came with a simple servo that could only do Vertical lock.  Thus  the 
need for a one line window TBC.  Thus you could High Band the machine  and 
not have to get an Intersync or Colortec.  
 
The playback in the side by side shows the quality of both.  If this  is 
the original, you can see the difference.  The aliasing will tell you  which 
is the Merlin machine.  The lack of a good drop out compensator will  tell 
you which is the Ampex original.  The Ampex machine used the built in  one 
that was included with the AFC modules.
 
Chris Hill
WA8IGN
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