So, I finally got my Fluke 45 fixed, after multiple broken parts. One of the parts that I had to replace was the EEPROM, which was totally dead, so I'm in the process of recalibrating it. So far I've managed to calibrate everything except the AC A range, because I can't think of anything stable enough to use as a standard. If anybody is curious, I've found these to be quite stable enough for the other modes, and used my HP 3468A to measure them as a transfer standard.

- DC V less than 20: Power Designs 2005 precision power supply
- DC V less than 50: Power Designs TP343A (seriously, this is actually stable enough that even the least significant digit on the 3468A completely froze)
- DC V 50-1000: homemade boost converter
- DC mA/A: homemade constant current source
- Ohms: Resistors mated to heating elements for thermal stability
- AC V less than 7: HP 3325A
- AC V greater than 7: HP 3325A -> buffer -> transformer
- Frequency: HP 3325A locked to a rubidium reference

I have no idea how to get a stable AC current source. For the lower current ranges, I suppose I could feed a constant AC voltage through a resistor, and just measure the current sense resistors in both meters and mathematically compensate for the difference. I don't really like that approach, though, and I like it even less for high current because of the heat generated. Any ideas? (And does the waveform matter? I would assume it should be a sinusoid, but a square wave would be much easier.)