For too long, I wanted a tube / valve tester that could test under 'actual use' conditions, match sections on dual triodes and run power tubes at close to voltage and current in actual use.
Finally, I got off my duff and did it with many thanks to all the ideas extant.
It's easy to modify for various tubes or add a 'patch bay' and external adapters for almost any tube.
The circuity is on a PCB making robust, modifiable and repairable.
Schematic, BoM, CAD drawings, wiring sketches supplied.
I'm happy to assist with any questions.
https://ielogical.com/assets/Lab/ValveTester/index.php
