I've been looking for a manual or at least a schematic for an EMC model 204 tube tester.

There's a single diode in there that was hack repaired on my machine that I would like to know the original specs on.

I don't know if this will help but I found it at BAMA. It is a schematic for a model 203 and the text makes it seem as though it is very close to the 202 and 204 models. There is also a schematic for a model 211 there if that helps.

Thanks pugs5061 - I appreciate that!