What is this goo? RCA CTC9 chassis

[Electronic M]

Originally Posted by dieseljeep

The CTC9 never used 5U4's, only a voltage doubler.
Also, the set was designed when the normal line voltage was between 115 to 120 volts. Now, most of the line voltages are running slightly above 120 volts so the transformer will run a little hotter.

I'm probably confusing it with the CTC7....then again I've owned every Roundy color RCA except for CTC7-12 so not having worked on those I know less about them.