Well, it's been a few years. My 1700B has decided to cease operation, so it really is time for a repair and full rebuild. Here's what I am planning:
- Replace all electrolytic caps in the unit. One of the main filter caps is dead, so it's time to do the lot.
- Replace all the carbon composition resistors. A quick check on half a dozen has shown a 15 ~ 25% upward drift. Why did ST use CC resistors? I've been using cracked carbon since the 1960s.
- I was going to replace the OP amps with LME49710 OP amps, but, well, you know. NLA. AD797s look like the best, available option. Any other suggestions?
- Replace all the opto couplers.