t2p

20250414 - We repair two Hewlett Packard HP 59501B units, and use them to transform a mundane 1960 HP power supply into a digitally programmable one.

HP 59501A/B manual scan, including readable schematics page: https://archive.org/details/hp-59501b-manual

Buy your own HP repair fancy pants: https://shop.curiousmarc.com/products/mr-fancy-pants-plaid-pants

Stuff that supports the channel:
- Support us on Patreon: https://www.patreon.com/curiousmarc
- Amazon links for the tools I use in the lab: https://www.curiousmarc.com/amazon-links
- Channel merch on Fourthwall: https://curiousmarc-shop.fourthwall.com
- Legacy channel merch on Teespring (I don't have everything transferred to Fourthwall yet): https://teespring.com/stores/curiousmarcs-store

"Elevator Music" Credit: Crinoline Dreams by Kevin MacLeod

Our lovely sponsors
- PCBWay: fast turn PCBs, https://www.pcbway.com
- Electro-Rent: https://www.electrorent.com
- Keysight: test instruments: https://www.keysight.com
- Samtec: connectors: https://www.samtec.com
- R&D Microwaves: https://rdmicrowaves.com

Get more technical info on the companion site: https://www.curiousmarc.com
Contact info: https://www.youtube.com/curiousmarc/about

0:00 Why we need the HP 59501B DAC
2:19 My collection of HP 59xxx instruments
4:05 Trying out the 59501B, the bipolar scale is out of cal
8:10 Calibrating the 59501 unipolar range
10:13 Oops, the bipolar range won't calibrate! But why?
12:46 Full schematics explanation (Elevator Music section)
22:29 Repair
25:58 Post repair calibration
27:39 It now exceed specs by 10x!
29:05 Repairing the 2nd unit
30:45 Turning an analog power supply into a digital one!