[QuadList] VTR introduction anniversaries: 1965

Thu Feb 10 15:07:47 CST 2011

Thanks for the info, Chris, will use it in my next life, doubt I will see any more 2" machines, been retired 2years already and all mods at CBS were done at least 30 years ago.  I don't remember what I had for lunch.
George

-----Original Message-----
From: Chill315 <Chill315 at aol.com>
To: quadlist <quadlist at quadvideotapegroup.com>
Sent: Thu, Feb 10, 2011 11:15 am
Subject: Re: [QuadList] VTR introduction anniversaries: 1965

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 
To: Quad List 
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 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 writes:

_______________________________________________
lease trim posts to relevant info when replying!
end QuadList list posts to QuadList at quadvideotapegroup.com
our subscribe, unsubscribe and digest options are here:
ttp://mail.quadvideotapegroup.com/mailman/listinfo/quadlist_quadvideotapegroup.com

_______________________________________________
Please trim posts to relevant info when replying!
Send QuadList list posts to QuadList at quadvideotapegroup.com
Your subscribe, unsubscribe and digest options are here:
http://mail.quadvideotapegroup.com/mailman/listinfo/quadlist_quadvideotapegroup.com

_______________________________________________
lease trim posts to relevant info when replying!
end QuadList list posts to QuadList at quadvideotapegroup.com
our subscribe, unsubscribe and digest options are here:
ttp://mail.quadvideotapegroup.com/mailman/listinfo/quadlist_quadvideotapegroup.com

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://quadvideotapegroup.com/pipermail/quadlist_quadvideotapegroup.com/attachments/20110210/d9d82b28/attachment-0005.html>