[QuadList] New Picture Quiz

Don Norwood dwnorwood at embarqmail.com
Thu Nov 8 08:21:55 CST 2012


Chris wins again!!!   He's a tiny bit off on the details, but an excellent job of deducement!

The picture is of the back end of a capstan motor for a VR-3000, showing the tach amplifier.  As far as I know, the VR-3000 was the first quad to use a DC motor and an optical tach for the capstan servo system.  The only part that Chris missed was that the three circuits aren't due to three phase, two are amplifier stages for each of the two optical pickups, and the third is the output stage for the combined signals.

This particular motor has an interesting story that's not quite complete yet, but when it is, I'll post it to the list.  Here's a side view of the whole assembly.  A cover has been removed from the rear to expose the tach area.



Don Norwood
Digitrak Communications, Inc.
www.digitrakcom.com
  ----- Original Message ----- 
  From: Chill315 at aol.com 


------------------------------------------------------------------------------


  I am going to guess and this is a guess only.

  It is from a VR-3000 and may be part of the capstan.

  Reasons.  Three identical circuits, thus three phase.
  Head assemblies could not have this on the spinning portion due to balance problems at speed.
  Size of parts indicates that the picture is larger than real life.
  Due to need to be small, thus VR-3000.
  Part has to be from a quad so thus the logic says what machine had small parts?
  And lastly, it meets the standard Ampex circuit board look.

  Chris Hill

  In a message dated 11/5/2012 5:00:11 P.M. Eastern Standard Time, dwnorwood at embarqmail.com writes:
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