[QuadList] What is it????

[Don Norwood]

Hi Chris:

I'll agree that the IVC interchange was better.  Beyond that, both the electronics and the transports had issues.  While the transport looked very "professional", a check underneath revealed some serious shortcomings, especially the lack of direct drive servo system for the drum.  As the machines aged, this became even more apparent when the pulley wore to the point that the head could never achieve speed!

As for the TBC designs, the analog TBC-790 came out in '72.  At that point, I'd guess that the cost of digital was still too high for the helical market.  Two years later in '74, the TBC-800 was introduced as Ampex's first DTBC for helical.  Weighing in at a mere 100 lbs compared to the 120 lbs of the 790, it had a 1-H correction window and list price was $11,500 plus an additional $3,500 for Velcomp.  The 790 had been priced at $10,000 for the base unit and only had a correction window of +/-1.5 usec, so for about the same price, there was a huge performance increase in two years.  Then, in another two years ('76), the TBC-1 at $12,800 plus only $1,500 for Velcomp offered a +/-6H window for less cost than the TBC-800.  It was also down to a lightweight 80 lbs!

Don Norwood
Digitrak Communications, Inc.
www.digitrakcom.com
  ----- Original Message ----- 
  From: Chill315 at aol.com 
  To: quadlist at quadvideotapegroup.com 
  Sent: Saturday, May 14, 2011 7:02 AM
  Subject: Re: [QuadList] What is it????


  Bill

  Very interesting history.  I have used a few different models of the EIPD machines.  7000, 7500, 5000 series and a 7800.  They were decent but had issues.  When IVC came along, a number of us wished that one could combine the Ampex electronics with the IVC transport because it held interchange a whole lot better.  Actually we were complaining about the swing arms in the EIPD machines.  

  The TBC designed for the 7900 was interesting.  I still wonder why that path was chosen for the design.  Was it because it was so early in the digital age that the cost was too high to produce a TBC?   Was it too early for the engineering skills?  Was there a time issue to get the product for market?  Or was the culture at Ampex such that it had lost its way.

  I remember being told about the letter for the discontinuance of InstaVision.  It said something like "Due to the unprecedented success of Instavision, we are discontinuing the product."  A fellow by the name of Doug Mumley was working for EIPD here in Detroit and saved the letter.

  Chris Hill
  WA8IGN
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