Heater/Cathode Leakage testing

[maxhifi]

Been working on a couple old GE radios.

Typical cheap AA5 AM only radios from the mid 1960s.

My EICO 667 has been amazing for tracking down heater/cathode leakage issues.

For the first radio The 12BE6 failed miserably with 1M, and replacing it cured an annoying modulation hum issue I was dealing with. I also replaced the 50C5which had 5M leakage. The other three tubes all passed with flying colours.

What do the vetran techs use as pass/fail values? The 12BE6 made a big difference, the 50C5 much less.