CTC20 possible project

[old_coot88]

Originally Posted by rca2000

I am pretty sure you are MISTAKEN. I DO think the CTC-20 IS a roundie---the "last gasp roundie', from 1967. A bit like the CTC-16 BUT the chassis is more of a CTC-19 "beefed up" to run a 21FJ tube.

That is correct. It's a roundie. And it's a turkey. We sold several of them. They had weak vert sync right outa the box. The factory was kind enuff to issue a mod consisting of changing the values of two resistors in the sync separator circuit to improve it. They were half-watters of something like 270K and 680K, IIRC. Later runs of the chassis may (or may not) have the mod already done.
All the '20s I ever seen had lousy vert linearity even after the mod. Very hard to get decent ht. and lin. balance.
Caveat emptor.