Keithley 2000 - $100 - eBay (Some woman who had no history of test equipment purchases or sales, no idea where she got it, but aside from a yellowed front panel works perfectly.)
Tek TMO503 Three Slot Power Module with PG506 Cal Generator, TG501 Time Mark Generator and SG503 Leveled Sinewave Generator - $80 - eBay
The whole thing turned out to be in rough shape; the modules were all erratic, which turned out to be an issue with the power supply. I replaced a diode bridge and all the caps, added BNC connectors on the back and scrubbed the chassis clean. Works perfectly now.
I also disassembled all three modules and scrubbed them clean, reseated all the ICs and lubed all the pots and switches. The SG503 turned out to have two broken contacts on the cam switch, switch I found replacements for. I broke a BNC connector off the PG506's fast rise board, which I'm trying to find a replacement for; I also replaced all the 74-series ICs with new LS versions. As for the TG501, everything works perfect expect for the 2ns and 1ns modes. I'm currently trying to fix that.
Cosmetic wise, the modules look really beaten up; broken levers, chipped corners on the faceplates, etc. But considering these were all made in the mid-70's, still work and are all in-cal, I can live with it.
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