Hello MarkL and med6753!
progress update, Have total 4, the working units are a 2467 IEEE and another 2467B
Both 2465B CTT/2467B needed A5 board cap damage and NVRAM fixes and restoration.
All low hours (2K, 3K, 8K) physical/cosmetic excellent.
0/ Analog calibration: set 10.000 V REF and DAC REF (+/- 1.25V) procedure. Notice the initial settings if you do this!
1/ FAN: original Nidec 12V 0.16A still useable. Substitutes had wrong current or low airflow.
Peel paper label, drop of oil on ball-bearing. Added 0.035" thk 1.5" dia neoprene between the fan hub and sheetmetal rear bracket.
Fine for noise. PS: Old fans (soldiers) never die, they just fade away (apologies to Gnl Douglas McArthur).
1A/ Heat/U800: Seems a lot of notes and some disagreement re the original U800 thermal desing and lifetime.
2467B original U800, no heatsink, 2465B original TEK U800, resoldered or replaced in the dim past, with a small heatsink.
Temps seem cool. QUESTIONS: a. setup to check worst case U800 temp, fastest sweep rate?
b. With no HS and TEK U800, what typical temp are recorded with cabinet closed? Cabinet open?
2/ CAL: After A5 rework and load new NVRAM with default image, 2465B was CTT FAIL, after CTT CAL, ALL PASS!
Check: Vert ampl ~ 2-5% all ranges, HOR ~ 1%. Useable but need CAL. Fast rise edge response OK (PG506) but need TD pulser for HF/Edge CAL. Trise ~ 900 nS.
After CAL, unplugged both NVRAMs, to read and save NVROM images. (used XGecu "MiniPro" TL866CS programmer $40)
3/ LAMP: Graticule lamps: 5.0V 0.115A T-3/4 40,000 hrs 7153AS15 at DK 7153AS15-10PK-ND pack of 10!
4/ PSU: All units seem fine, PSU voltages and ripple OK. Visual of RIFA caps and lytics seem OK. To the 2465/7X PSU veterans and rebuliders:
a/ Leave it alone or recap? b/ Time/tools/pitfalls to pull and rework PSU? c/ BOM: Source for caps, special resistors, rectifiers, etc?
For some years, and last few months, I worked on these scopes, with fine components, gold PCBs, complex but easy to service mechanical and well written documentation.
As I reread the manuals and did some CAl, I realized what a fantastic quality design the TEK engineers did.
Amazing that these machines (1980s..early 1990s) still work perfectly, there is no modern replacement!
What a contrast to the minimum cost/life/performance digital Chinese junk marketed today with deceptive specs and compliance.
Again many thanks to all for the great feedback and support info.
Jon
PS: Please see my SIGSALY first ADC recreation in February IEEE Spectrum:
https://spectrum.ieee.org/geek-life/hands-on/rebuilding-a-piece-of-the-first-digital-voice-scramblerhttps://spectrum.ieee.org/geek-life/hands-on/sigsaly-analogtodigital-converter-construction-and-debuggingYour comments and feedback appreciated.