Well bugger me whoever did the call on this scope was a fucking mong. The thing was calibrated at the wrong end of the variable detents . Slowly working through the cal process...
Fortunately, you're smarter than they were.
mnem
Cuter too.
I think a monkey is smarter
Anyway it's done, calibrated and it's working nicely. Only outstanding issues are a hefty gash on the shield and the cal signal loop is broken off. I will work out a cunning plan to resolve those issues shortly. Component tester works nicely. Latest date code is around 1983. All capacitors test fine as well.
CRT is pin sharp:
Cleaned up:
DG1022Z standing in as a time-mark generator.
Might buy another one if I see it for spares
Edit: some performance measurements:
1. Rise time = 12.5ns ~ 28MHz bandwidth. Not bad
2. 3dB point = 26Mhz. Also not bad.
3. Triggers to = 48MHz. Pretty good
4. Displays signal to = 92MHz. Pretty good.
Not bad for a 20MHz scope.