[QuadList] Ampex Quad VTR Airflow Requirements

[Don Norwood]

Hi Larry:

Interesting indeed!  I'm also surprised that the normal vacuum is 35 instead of 40.  Somewhere, I have a SMPTE standard for the quad format, and I thought the 40 inches of H2O vacuum value was in that but maybe it's just the geometry of the guide.  I'll see if I can find it. 

I've often thought of compiling a list of differences in the way that RCA and Ampex machines were designed.  Now I know of more than I did!  I can remember some spirited debates back "in the day" over the virtues of one machine or another.  I always thought that both RCA and Ampex had their strong and weak points, and taking the best of both would have made an interesting machine.  To some extent, that's what happened in the later models.

Don Norwood
Digitrak Communications, Inc.
www.digitrakcom.com 

----- Original Message ----- 
  From: L.E. Odham 
  To: Quad List 
  Sent: Saturday, June 02, 2012 1:52 PM
  Subject: Re: [QuadList] Ampex Quad VTR Airflow Requirements


  Hello Don,



  Attached is a manual page from a RCA TR-60 describing the vacuum arrangement.

  When the machine is in standby or winding the gauge reads 100 in/h2o and when in play or rec modes it drops to 35in.(Ibelieve I said 40, but it is actually 35in.)

  I dont know when RCA instituted this vacuum switching arrangement or how many models it was on, but it is on the 60 here, and it was on a 61 at work years ago. 

  I will look around thru some more RCA manuals here. You have gotten my curiousity up a little now as well.



  Larry



  LE Odham

  Engr/Tech

  TAMIS Archive

  Knoxville,Tenn.





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