Final check out of the 535A. Attempted to do some frequency response checks. Things didn't go so well as I'll explain.
The set up. Tek Type 191 Signal Generator. It can go all the way up to 100MHz.
I attempted to trigger on a 11MHz sine wave. No go. It wasn't until I lowered the frequency to about 9.5MHz that I could get at least some trigger. If I lowered it more down to about 9.1MHz I could get a stable trigger. And that's the disadvantage of these old tube triggers. The manual states it good to 5MHz and I guess they ain't kidding. But I was able to stretch it the 9.5MHz.
Here it is right at the limit at about 9.5MHz. Very unstable. Sweep speed set to 0.2us and 5X mag on. Aptitude set to 1.0V p-p. Any higher than this and it drops like a stone and screen goes blank.
At about 9.1MHz it's stable.
At this point this project is done.