Ah, I see. I hadn't read much about electrostatic deflection until now. I guess the electromagnetic method was just better suited to televisions. Perhaps it was easier on the development process as CRT's got larger.
I've been looking into this whole oscilloscope thing in more detail and I think I've about got it figured out. Looks like it's not too hard to dial in waveforms, once you have an understanding of how they'll appear and what you need to adjust to bring them into view. Took some readings today on my Zenith, starting with the 12BY7 video amp. With those contrast problems I've had, I'll probably be poking around in that area a good bit. I just tweaked the controls until I got something that matched the waveform on the schematic.
Here's what pin 7 off the 12BY7 looked like:
And pin 2:
Really interesting stuff! It's cool to see how the waveform fluctuates, corresponding to the moving images on the tv screen. Not making any specific measurements here, just trying to get a good waveform that matches the schematic. Good sign that I'm starting to "get it" and will hopefully be able put this instrument to good use.