Poor focus on an Admiral 20Y1

[bandersen]

Not sure what you mean - this chassis doesn't have DC restoration.

[Kamakiri]

As in way too much gain in dark scenes and far too little in light scenes

[Eric H]

Maybe one of the sections of Cap C1 is faulty? I know you replaced them but what would happen if one is bad? You could jump another one across them easily enough.

[old_coot88]

Originally Posted by Kamakiri

As in way too much gain in dark scenes and far too little in light scenes

I don't have the schematic, but check the grid resistor (G1) of video amp stage(s). If it goes 'waay high in value, it causes a partial 'floating grid' condition, leading to the symptom you describe. Also check the cathode resistor(s), if any.