I agree with Rob, your oscillator is most likely off Freq. When you replace the HOT cap, you are causing your tube to conduct HARD and kill the B+, thus loading down the B+ to the Audio CKTs.
Can you use a scope? If so, I have a detailed procedure for checking the Output and Osc circuits on your set. It comes from a bench-training course on the CTC4 chasis.
The neg. voltage to the grid of the HOT is an approx. DC value. You need to verify the waveforms at this point. The "duty cycle" (time on and off) must be right.
Also..anytime a tuned circuit needs to be tuned to the end of it's range to work, a close look a the components is needed.
E-Mail me if you like, I'll scan the pages and send, or copy and mail.
Thanks,
Kirk
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