[Mondial]

That 10 uF dry electrolytic in the early model 80 was a low voltage cap, placed across the bias resistor (#36) in series with the power transformer center tap to ground. Evidently it never needed to be so big because it was replaced with a .015 uF paper cap (#32 on the schematic) in later production.

I have a feeling the same thing happened with your receiver. Philco found the electrolytic was not necessary and eliminated if or replaced it with a smaller paper cap.

I am sure a 1 or 2 uF would work fine as a cathode bypass.