On 15/12/2020 11:26, Spike wrote:
On 15/12/2020 08:22, Grumps wrote:

A friend has acquired an old Goldstar OS 7020 dual channel CRT based
'scope, and I offered to check it out to see if it is all working.
So, mostly it is fine except that the timebase wanders randomly,
sometimes speeding up, sometimes slowing down. And it does this to the
same degree in ALL timebase settings except the X-Y mode.
I take it you get a stable Lissajous trace in X-Y mode?

I get a stable dot that doesn't wander when I have it set to X-Y mode
and no inputs.
I'm pretty sure the problem is in the sweep generator and not the
horizontal amp.