Museum of the Broadcast Television Camera

E-mail Received, 15 January 2012

Harris TC-90 camera

Kevin, writes:-

I left Harris in 1985 and overlapped the development of the TC-90. I was not really involved in the development of the TC-90, but it was 50 feet away in the lab and I had of course worked with Gary and Brian in the past so I was always wondering in to see what was going on. The controls and setup of the TC-90 were based on a National Semiconductor NCS-800 processor. It was a Z80 knock off. The code in Forth again. I did not know that they abandoned the TC-90, but I can tell you for certain that not all were destroyed. I have a complete TC-90 sitting here next to me. The power supply mostly works, but as a high pitch squeal to it. Most likely a 30 year old tantalum cap failed. I am attempting to repair it back to working order. By the way, the TC-90 was released in both Plumbicon and Vidicon versions. Mine uses Plumbs. The power supplies were different in the two versions to adjust for a voltage requirement that was different between the two.

I picked it up recently and the manual that came with it had several photocopied pages of Gary Sandersons original hand drawn schematics, modifications, and notes. I have scanned these and sent them to Gary this past year (2011) and would gladly send them to you if you wish.

To the best of my knowledge, all of the PE and TE series were all rebaged GE and the TC series were original Harris, although design by some of the original GE engineers. Art Wymer was one of them that I worked with. Art came in from GE in New York as did a few others. Sorry, but I cannot remember any of the other names off the top of my head.

I am a HAM also (AD7OI) and an ATVer. I belong to the BATC and stream most Wednesday and Sunday evenings at 18:30 and again at 19:30 GMT-7 both as AD7OI member streams and on W7ATV repeater feed when it's my turn.

Cheers. Kevin AD7OI

E-Mail #2:-

Hello Brian,

I have attached three PDF's of some of the additional info that came with my TC-90. I have the manual as well, but did not yet have it scanned. I scanned the other documents to send to Gary Sanderson. Gary was the primary engineer on the project I believe. He would of course know a lot more about the camera and what went on. There was another fellow that was a very good RF and video guy named Charles White I believe. I am a little uncertain of the last name, but that is what I recall, I will ask Gary to confirm. We all just called him Charlie and I believe he was from GE originally. He worked on the TC-90 as well. Charlie also did quite a lot of work on (or perhaps designed) the Harris Triax add-on for the TC-80 in the 1976-77 time frame as well as the A/D board of the TC-85 Auto Setup unit later and at least one Harris Modulation Monitor with a Plasma bargraph display, the AM-80. I prototyped the first AM-80 unit from Charlie's schematics during one of my summers at Harris. I am certain he did much more, but I worked with Charlie as a summer student / tech on these and they are the only projects I am certain of.

I will try to get the manual scanned and sent to you soon. I will also take some pictures of the TC-90. I have the case off now for the power supply repair, so I will get some internal shots for you as well while it's off.

Cheers. Kevin AD7OI

Gary Sandersons original hand drawn schematics, modifications, and notes:-

PDF file for TC-90 optional remote control connector specifications.
PDF file for TC-90 board design.
PDF file for TC-90 board layouts.

PDF file for TC-90 Operators Manual.