- 2026
- Jan
- 25
A Leader LBO-310A Oscilloscope - Part 2: Diagnosis
In the first part, we checked out a Leader LBO-310A oscilloscope. It seemed to have a very simple problem, one where the vertical centering wasn’t working. This is due to a bad potentiometer where the carbon ring on the internal wafer is just worn from age. The pot in question is the one closest to the edge in this picture:
I picked up a few parts, but it turns out this one is just a little different. Older Japanese equipment tended to use potentiometers that were just a bit smaller than the ones we used in the USA. 6mm shafts instead of the 0.250” (6.35mm) that we used, with a correspondingly larger mount. So…the ones I bought won’t fit. I could make them fit, but then the knob won’t fit the shaft.
So…
I have some on order that claim to have a 6mm shaft. They’re genuine Alpha pots, so they should. “Should.” If not, hopefully I can just remove the wafer from one of them and swap it out. Otherwise, it’s waiting for a show where I can dig through some junk bins.
Stay tuned!
Next part of this series: Coming soon.
Previous part of this series: https://wereboar.com … part-1-observations/