[QuadList] Amtec Centering Meter Drift

[Chill315 at aol.com]

There are two reasons that the meter can show drift.  
 
First the Intersync is drifting Horizontal position with respect to house  
sync.  this is easy to determine.  Look at the demod out on an  externally 
synced monitor or turn off the Amtec, Colortec and put the Proc  Amp in 
regenerated sync mode.  The look at the output on an externally  synced monitor.  
See if the H position is changing.  If so then the  Intersync is moving H 
position.
 
Second if the first does not show a change, then the problem is in the  
Amtec.  Most likely board 2, the External Pulse Advancer.  
 
I would do the following.  Set up the Intersync test and monitor the H  
Phase error TP on the top of board 4 with an oscilloscope.  If it does not  
change, and the position does not change, then go to the Amtec and monitor the  
TP 1 and TP 2 on board 2 with respect to external sync.  This would give me 
 a clue as to which is moving.
 
If neither moves then I have to re think my testing.
 
Chris Hill
WA8IGN
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