I spent a couple of hours last night making a little probe compensation loop
for my R7844 out of a couple bnc connectors and a cannibalized comp loop
from the front of a TEK 7904 I parted out. It didn't work as well as just
sticking the probe into the BNC connector out from the square wave reference
oscillator of the R7844. I know TEK offered a bnc to compensation loop
adapter for the R7844 (haven't seen any available, though.)

What am I doing wrong? Does it matter if I just stick the probe into the bnc
without the loop? I was able to compensate the probe for a pretty square
output this way, using the highest output voltage setting on the oscillator,
but I'm just curious why my mickey-moused compensation loop was useless.

Also, although my output looked like a pretty square wave, it only displayed
the horizontal lines.... No vertical lines were visible on the swing from
peak to peak. Is this indicative of a fault, or am I just missing something
obvious? I am relative newcomer to scopes in general, and I've been slowly
acquiring plugins for my mainframe (which I rescued from the dumpster, along
with a TEK 7904, all without plugins.) So far, it looks like the power
supply is a little out of spec (the character generator output seems to
jitter vertically for a few minutes before finally stabalizing. I will recap
as many electrolytics as possible just because I figure a 30-plus year old
electrolytic is probably suspect. I have a nice supply of spare parts from
the 7904, as far as logic chips, transistors, etc.

So far, I probably spent about $100 in plugins (7A26, 7A18, 7B53A, 7B80)
and probes. The CRT seems fine, and for a dual beam 400Mhz scope, I guess I
don't have much into it, money wise. It is probably overkill for me, since
I'll only be doing audio band stuff, but I have fun playing around with it
for the moment. I probaly could have found a working 2000 series for a
little more than what I've got in my dumpster find, but I seem to be
developing an addiction to dumpster diving and tinkering.

Anyway, any thoughts on my rant are welcome.

Tod