After watching Dave add binding posts to his Agilent 6643A on the same day that I (yet again) had issues with my switch-mode Extech supply, I started taking a look the Agilent 66XXA supplies and saw that they are seriously awesomely built. Anyway, I have now bought 3 on eBay: a 6642A, a 6643A, and a 6623A, all apparently working and all at reasonable cost. I must be crazy but I guess I can sell them for around what I paid. Here's what I'm thinking:
6642A and 6643A - Clean up, add missing parts (knobs and feet), maybe add binding posts.
6623A - I was unaware of these until today, they have 3 dual-range outputs that scale between a high and low range so, for example, one of the outputs can run 7V at 10A or 20V at 4A, if you go over 7V it auto-shifts up to the 20V range but then is limited to 4A. All the outputs are isolated from each other and ground. Apart from the rear terminals, the biggest issue with the 6623A is that it has no rotary encoders on the front so you have to enter any changes to voltage and current from the keypad. However, there's apparently an RS232 input on the back from which you can control everything so how's this for a neat conversion idea. Add 3 sets of binding posts, 3 rotary encoders and 3 buttons. Now add a microcontroller and program it so that it sends the correct signals to the serial port when the buttons and encoders are operated?