View Single Post
  #25  
Old 04-04-2017, 05:47 PM
old_tv_nut's Avatar
old_tv_nut old_tv_nut is offline
See yourself on Color TV!
 
Join Date: Jul 2004
Location: Rancho Sahuarita
Posts: 7,193
Quote:
Originally Posted by J Ballard View Post
So NBC, AT&T, and Zenith bought Bosch KCH-1000 flexible standard cameras with Saticons. By changing dip switches and many ROMS, you could operate the camera in interlace or progressive. The complete camera, including image enhancer, was almost $500K. I wrote the PO, and no one flinched.

JB
A few more notes on the KCH-1000. It was very flexible, but not quite enough for the progressive scan. The viewfinder could not run at 47kHz horizontal and had to be redesigned. Also, the digital control circuits ran at 27 MHz. These took special high speed (for the time) CMOS ICs, so we had to buy them only from Philips to have stock for any repairs.

Zenith and their partner, AT&T each bought a camera, and with the modifications we were charged $800k apiece. These cameras also followed the same practice as Sony and others at the time, of reducing the video bandwidth to 22 MHz or so to reduce the noise, but we needed 32 MHz to get sufficient H resolution with progressive scan. We immediately discovered the 27 MHz digital clock and control signals were running all over the chassis, and spent a lot of effort adding shielding and grounds to get it out of the video.

We also had to design and build our own aperture corrector/edge enhancer to work with the progressively scanned signal.

Fun!
__________________
www.bretl.com
Old TV literature, New York World's Fair, and other miscellany

Last edited by old_tv_nut; 04-04-2017 at 05:50 PM.
Reply With Quote
Audiokarma