[QuadList] Ampex Quad VTR Airflow Requirements

[Don Norwood]

Hi Roger:

The air supply requirement for VR-1100/1200/2000 when equipped with the 
venturi update is between 50 & 55 psi at just under 1 scfm.  When properly 
adjusted, the head air warning will come on above 55 or below 50 psi, and 
the head air interlock will cut out below 40 psi.  Air supply must also be 
dry and oil-free.

For a single machine, a compressor that can deliver 1 scfm at 100 psi gives 
a comfortable cushion and a reasonable cycle time on the compressor when 
using a properly sized tank.  Obviously, there are a number of variations of 
scfm/pressure/tank size that will yield acceptable results.

The original Ampex and RCA approach was to use a compressor that was just 
slightly oversized, and it ran continuously with a relief valve.  That works 
too, but I much prefer a "central air" design, even when using a single 
machine.  Beware of cheaper oilless compressors which tend to run very hot 
and are not designed for continuous duty.  My preferred brand is Gast, and 
you'll find a large variety of compressors if you check their website.  The 
rocker style can be used for a single machine, but I still prefer the piston 
style and their higher output.  Quietness (a relative term!) may also be a 
consideration depending on your situation.

If you have any specific questions, let me know.

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

----- Original Message ----- 
From: "Roger Brett" <rcbindy at comcast.net>
To: <quadlist at quadvideotapegroup.com>
Sent: Friday, June 01, 2012 1:11 AM
Subject: [QuadList] Ampex Quad VTR Airflow Requirements


> Hi,
> Does anyone have info regarding air system requirements for the typical 
> Ampex VR series quad machine?  I'm planning the air supply system for one 
> fairly soon.
>
> It's been quite a while since I maintained one of these, and I don't seem 
> to have this data on file.
>
> I don't have physical access to the unit yet, but besides the air bearings 
> on the head, I believe it has a venturi system to generate vacuum for the 
> guide.  This aspect would of course increase the flow requirements.
>
> Data I'm trying to get:
>
> - Max (worst case) CFM of airflow needed for bearings and venturi combined
> - Nominal air pressure needed at the head bearings for proper operation
>
> Any help would be appreciated!
>
> Thanks,
>
> Roger Brett
>
> Please trim posts to relevant info when replying.
>
> Change subject to reflect thread direction. Thanks.
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