Rca 621TS

[miniman82]

Most common offenders tend to be drifted height/lin pots, but you can also futz with the values of the dropping resistors feeding the vertical section B+ to squeeze more height out of it. I have to do that with color sets sometimes, not sure why. For example if there's a 1.8 meg fixed resistor feeding boost voltage to the vertical section and it's in spec but the picture isn't tall enough, I'll stick a 1 meg in there and see what happens. Could be that the magnetic parts of the circuit like output transformer are getting tired, so compensation is required. Not sure, but it seems like giving it a little more voltage to work with is a sensible solution.