[jerryhawthorne]

Ken, although your readings on ohms are high, they are not infinite (open). I wouldn't worry about those at this point. When you were referring to no voltage on the plate of the 75, were you referring to the detector plates or the triode plate? The detector plates should really show very low voltage. And no, adjusting the trimmers on the transformer will not change resistance on the coils. Don't even touch them at this time!
What is the radio doing at this time?
Best, Jerry