[QuadList] VTR introduction anniversaries: 1965

[Chill315 at aol.com]

George
 
Remember to change the strapping's on the 12 volt shunt regulator power  
supplies.  The power supply had to be strapped for the correct load or it  may 
go down.  There is a procedure in the book that if we added  accessories, 
we had to change it.  The one in the edit machine was strapped  differently 
so I had to make sure not to swap them.
 
There were not tubes in the VR-1200 for the record amps.  That was an  
improvement that came along.  Probably due to improvements in transistor  
capabilities at the frequencies required.  The 1200 pre-amps were  transistorized. 
 It was interesting how AMPEX did the bit with the same  MK-X head for 
different series machines by just having interchangeable  pre-amps.
 
Chris Hill
WA8IGN
 
The 
 
 
In a message dated 2/10/2011 10:36:58 A.M. Eastern Standard Time,  
georgenann at aol.com writes:

The 1200 and 2000's had big hot record "Vlaves" in the RAPA's and  
Nuvistors in the heads.
 
At CBS in the "later Years" I pulled all the record amp tubes out and  
threw them away.  Also removed the fan in the head channel housing,  didn't need 
it, filter too, no need to replace it ever and less dirt being  slung 
around the place. Also the cabeling associated with record from the head  channel 
housing. Kept the modulator.
 
I don't think anyone will be doing any 2" recording on those machines  
anyway.
 
Also pulled "Erase Head Chassis" and anything else I could find that  
wasn't needed anymore.
 
I would have pulled the Editec, Editor and VHO but couldn't find one of  
the original "Dummy Plugs".
 
I did the same on the last 2 AVR-1's located at "Archives".

I just liked the "Clean Machine" look and anything that made getting  
around the inside a bit easier made life a little "Better".

Please don't tell any of my bosses, they might be mad.  OH -  Nevermind, 
they have all retired, like me.
 
George Keller



-----Original  Message-----
From: Don Norwood <dwnorwood at embarqmail.com>
To: Quad  List <quadlist at quadvideotapegroup.com>
Sent: Thu, Feb 10, 2011 10:13  am
Subject: Re: [QuadList] VTR introduction anniversaries: 1965


Apparently you don't need recapping at all Guy!  The record amps did  have 
tubes in the VR-2000, 3 in each channel!
 
Don

----- Original Message ----- 
From:  _Guy Spiller_ (mailto:quadruplex at verizon.net)  
To: _Quad List_ (mailto:quadlist at quadvideotapegroup.com)  
Sent: Thursday, February 10, 2011 8:47  AM
Subject: Re: [QuadList] VTR  introduction anniversaries: 1965


I seem to remember the VR-2000B that I worked with back in  the day, also 
had tubes in the four record amps....similar to the early  TR-70s.  
Seems like those big tube record amps were one of the  major differences 
between a 1200 and a 2000.
But, then again, my memory  may need recapping.
Guy

On 2/10/2011 8:39 AM, _Chill315 at aol.com_ (mailto:Chill315 at aol.com)  wrote:  
I got the brains working a little better.
 
The tubes in the VR-2000 were in the Mark 10 head pre-amp.   These were the 
four Nuvistors.  Don't see those any more.  The  manual that came with my 
1200 talked about shorting bars in the head  pre-amp to reduce the gain.  I 
have no idea how that worked.
 
There TR-70 had a modification kit for the machine to replace a  tube 
driver in the record amps.  It was something I remember the U of  M Dental school 
operator showed me.  
 
Those were the only tubes that I am aware of other than the scope and  
monitors in the units.  
 
The audio was transistorized as stated in another reply.  There  were 
several modification bulletins for this part of the machine.
 
Chris Hill
WA8IGN
 
 
In a message dated 2/9/2011 11:12:09 P.M. Eastern Standard Time, 
_park at videopark.com_ (mailto:park at videopark.com)  writes:







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