Well, at least I started diagnosing on the correct page this time. :)
You could grow old thinking about all of the things that could go
wrong with a 7T11.
I have had problems with the board to board pin connectors Tektronix
used before that were solved by going through and bending the little
leaf springs to tighten them.
Tektronix used that dual transistor transmission gate design in a
couple of different places in the 7T11. I wonder how its performance
compares to using diodes or a single JFET.
On Sat, 26 Jan 2013 18:31:43 -0000, "David C. Partridge"
<david.partridge@...> wrote:
The fault was in the Dot Position Memory circuit on the logic board, or more exactly the lack of a gate signal arriving at the base of Q650. Once I'd got that determined, removing and re-seating the timing and logic boards solved the problem.
So the sweep wasn't truncated, it was partly off screen.
Dave
David Hess