Tektronix 222 AUTO LVL PUSH control and display glitching ...

[mossygreen]

I just got a Tek 222 from an online auction and ran it through its paces. Everything I've worked looks good but the inner knob of the trigger control (AUTO LVL PUSH) doesn't hold the shaft it's on (something is off w/r to its set screw, but I can fix that) and the shaft itself just freely rotates. Reading the manual I can't see that rotating it would have any utility. However, it's really odd to have a round control where turning it has no effect. Pushing on the control or shaft has the documented behavior and you can feel a distinct "button pushed" sensation. Given that the label on the control has an orientation I would expect it to not turn at all.

I can imagine that something is loose inside but before I got looking I thought I'd ask to see if other people's 222's have the same property.

W/r to the display glitching ... it looks a little like infrequent noise showing up in the signal at the rate of 0.2-2Hz. My analog 2465 doesn't do that, nor does my modern R&S scope. Is this to be expected, or a sign of something wrong?

[m k]

It seems that all Tek folks have been elsewhere.
Manual says it's different from its buddies, button of some kind I guess.

Have you advanced?