Hello all, new to the group and happy to be here.
I just wrote a long intro about me and my new Tek 465 into the Yahoo groups
'new post' textbox, but it seems to have vanished ... so I'll briefly recap
(pardon the pun). I am a web and database programmer during the day but
have dabbled in electronics since I was 10. I'm in my 30s now and getting
back into modding my audio tube amps. I've always been building kits and
fixing through parts swapping in TV power supply boards, digital Arduino
projects, RC planes etc. But I've never really learned the math or
theory/design side of the analog world. As I'm looking to build some
personal audio gear (active crossovers, maybe some tube mono-blocks) I'm
teaching myself more theory. And I'm a very visual person and like learning
through gear so thought I'd get an analog o-scope.
Well I stumbed upon an as-is Tek 465 on Craiglist that I picked up Monday
near Chicago. I'm blown away by the detail in the service manual I found
online and the serviceability, and am starting with the power supply diag
in the manual to try to get things running. I don't have high expectations
for accuracy - I know a detailed calibration is a profession in itself. But
getting even rough readings would be a big help for me as I learn.
Current condition of the scope is a single dot in the center with no sweep.
Fan and lights work, knobs in good shape. Very complete scope but the sweep
IC gets super hot. I figured I'd have to swap a lot of caps and transistors
and maybe some regulators, but hoping I don't have to source the custom ICs
(but found a source so I guess there's hope).
So far I've confirmed a solid +55v rail, +15v rail and a drooping +5v and
no -8v with my DMM. The +5v droop goes away if I isolate the horizontal amp
board by pulling the connector. I posted on the EEVBlog forum and got a
response saying to check the ripple as well; seems I need another (working)
scope? Any hope that a cheap USB scope (opposite end of spectrum from this
beast!) would suffice?
Thanks in advance for your knowledge; I'll ask more detailed questions and
post pics as I get into things.
- Neil
