Full disclosure -- I'm definitely still learning. I've tried searching the web, but in all honesty, I'm not getting very far, probably because I'm not sure of the exact terminology.
video of the issue
I have an old HP oscilloscope that I'm try to get working. I've compensated the probes, finally figured out that storage mode is way too tricky and I'd rather be in conventional mode, and gotten a rough idea for how time base and volts per division work.
However, when I went to try and measure a signal (500Hz square wave from an arduino uno), I'm having a tricky time getting the trigger setting to hold the wave. Attached is a video to showcase the issue. Also, the wave seems to tend upward, although it's fairly faint. I have channel A in AC mode, which I though would remove any DC offset that would cause that upward shift.
I should also mention, it's a x10 probe, an HP 10433A.
I've played around with the various buttons on the Trigger setting -- Pos/Neg, Low Fereq and High freq Rejection, AC/DC, INT/EXT, EXT/10, but I don't see any changes.
Is there something stupidly obvious I'm missing?