This project is like a see-saw. Two steps forward and one step backward.
The Amplitude Calibrator is fixed. Turned out to be a dirty switch. Deoxit took care of it. This is surprising because the calibrator uses the +125V supply as it's source and that's the section of the PSU that had the spectacular flames and smoke the first time I installed the PSU board and accidentally swapped 2 wires and applied +300V to that area.
The 3A3 plug-in has successfully had it's gain and DC balance adjusted on both channels. The gain on both channels needed to be increased an equal amount apparently due to the decreased sensitivity of the weak CRT.
I made an offer on Ebay for a Type 3B3 Time Base plug-in that was accepted because.......
The Type 2B67 Time Base has gone out to lunch again and now refuses to trigger as before.
Was working fine and suddenly quit. I also have the Type 3A6 Vertical plug-in which has a trace on each channel that I can move vertically up and down but if you apply a signal it's a flat line. In order to troubleshoot these plug-in's I need an extender cable so I can access the component sides of each. I can fairly easily make one but the issue is the connectors. They are Amphenol 24 pin connectors but I have no idea what the Amphenol P/N is. I can salvage a male off a junker plug-in but the female side is the issue. Google search on the Tek P/N revealed a source but rather than list a price they want you to submit an RFQ. Oh goody, I wonder how far I'll have to bend over and spread them when I submit it.
Speaking of the CRT. There's one on Ebay right now. Supposedly brand new. They want $100 USD plus shipping. They're nuts.
That's more than I paid last year for a CRT for the 7904. Granted, that one was used but still...I think a 561B CRT is worth maybe $50 USD at most. But this project has already turned into a semi money pit and unless the old CRT takes a complete dump it's staying in place. I got this entire Type 561B real cheap but it certainly ain't cheap now. But I'm a sucker for old Tek's.