Tektronix 453 - Time/Div dial has no effect

Question

I recently picked up a Tektronix 453 Oscilloscope and it works pretty much flawlessly, but turning the time/div dial (the clear plastic flange) does nothing to the display. I tried hooking up CH 1 and CH 2 to the 1 kHz calibration signal, and about 2/3 of the top edge of the waveform is shown, but I can't change how much is shown with the time/div dial. The time/div dial spins freely, and is incredibly hard to turn. I can get the display to show the falling edge and about 1/3 of the bottom edge of a single pulse as well by turning the A VARIABLE to the maximum, but that's as far as it goes. I was wondering how feasible it would be to repair, since I'm still pretty new to electronics, and which parts I should try to steer clear of.

Picture of the dial below:

`dial spins freely` and `incredibly hard to turn` are mutually exclusive — jsotola, Jul 17 '23 at 16:18
There is a service manual at https://w140.com/tekwiki/wiki/453 — D Duck, Jul 17 '23 at 16:33
`dial spins freely` as in there are no hard stops, but it has a lot of resistance. — Kestrel, Jul 17 '23 at 19:01
1) It sounds like the grease has hardened. 2) As it's a CRT oscilloscope, there are some things to be wary of, as mentioned in [Tek 453 Safe Repair?](https://www.eevblog.com/forum/testgear/tek-453-safe-repair/). — Andrew Morton, Jul 17 '23 at 19:09

score 0 · Answer 1 · answered Jul 17 '23 at 20:56

Never mind, I suppose I should have learned a bit more about the equipment before deciding it was broken! I was trying to turn the actual clear flange, instead of the dial itself. I guess I figured since it already did Delayed Sweep, it couldn't do anything else. Just turning the dial without pulling works perfectly. Thanks for all your help though!

Tektronix 453 - Time/Div dial has no effect

1 Answers1