Okay. So. I just popped this thing open to clean it and hoooly heck did I find some surprises. I don’t know much about oscilloscopes or oscilloscope mods from who knows when.
Ideally, I would love to remove the alien tech, but the scope works a-okay right now so I likely won’t mess with it. I may swap out the screws for nylon and insulate it a little better, though. Why do you think?
Update: I decided it was fairly obvious where the modifications were made. I went ahead and removed them to see if the functionality of the oscilloscope improved. It did not. It also did not get worse so: SUCCESS.
Here are a few clearer photos of the removed circuits:
Now I need to figure out why the Sweep, <> Position, and triggering likely aren’t working. I suspect the person modifying it removed wires to make their circuit fit. I suspect the posts are there to attach wires to and I count four without wires. I also count maybe two clipped wires.
I’m going to have a read through of the schematic, but I’m not great at schematics yet AND the schematic is in a format I haven’t seen.
Yes, in particular watch for the capacitors in the power supply. It’s not the kilovolts that kill you (though they could give you a nasty shock), it’s the relatively low voltage high charge in those big capacitors.
So I think I have it working almost as good as new. I’m currently reading through the service manual and will likely need to do a little calibration. The components all look pretty good. If I run into issues calibrating, I’ll take a closer look.
One thing I’m not sure about is the direction of the plastic lens with the grid on it. It could go in either way, but in the direction it came in, the grid barely lights up when I turn up the illumination. Currently, the grid is on the outside. I might try flipping it, but I’m a bit iffy on removing it as the plate that holds it is attached with brittle plastic snap-in connectors.
