I built the AWA Capacitor DC Leakage Tester

[duckduck]

I ordered the PCB and built this thing:

https://www.antiquewireless.org/homepage/pcb-item-4/

The PCB is USD25, delivered. It comes with an off-board schematic / wiring guide and a BOM (with Mouser part numbers). The AWA description claims that you can buy the rest of the BOM (minus case) for USD30. If you bought the cheapest components from lcsc.com maybe you could hit that price. I spent USD93 at Mouser (including USD24 on a steel enclosure from Hammond), and I had some things on hand already. I upgraded a few parts, and bought top-shelf brand name parts for the rest, so you could definitely do this cheaper.

I ended up getting the test/discharge switch wired up upside down. Don't know how that happened except that I work on my hobbies after the rest of the family has settled down for the night.

Review: It works. I like it. I own a good amount of "vintage" musical gear, so this will be a "nice to have" addition to the lab.

EDIT:

Sure would be nice to build a little test enclosure for the large 300V-500V capacitors, something like a Keithley 6104.