Hi Bill, I think, it is a question of the own philosophy. In the past, I have recapped all black beauties and waxies in old tv sets. "Old" here means sets of the 1950's. Tv sets from the 1940's do not exist in Germany. But a recapped chassis is an ugly look. Who wants a tv set with a recapped chassis? I believe, if you have the choice to select between two same tv sets, one in non-working condition and an untouched chassis, and another one with a recapped chassis in working condition: which one would you prefer?
If there is a necessary for recapping, I would prefer here a procedure like Steve McVoy suggested in his restoration philosophy for prewar sets:
http://www.earlytelevision.org/working_condition.html
My aim is to keep the original look as far as possible.
Some thoughts, why: I believe that none of these sets might be operable in 100 or 200 years. Lack, plastic and isolation materials might dry out, become leaky and lose their properties. Tubes lose their vacuum. Flybacks become porous. We can see (here in Germany) that caps which were reliable in the 1970s and 1980s now become bad one for another.
What would you think when you imagine that many vintage tv sets survived in 200 years, but none of them in original shape? So, with every historical tv set, you have to made a decision: should I repair it or not? Sometimes, it is of more value to keep an old set unfixed as it is than to bring it back to operational condition.
I know that old caps are a risk. I desolder one end of the usual suspects and test them with high voltage (500v or 1,000v), so I can see whether they fail or not. If they test good, I keep them. Aside from this, most of the caps with a parallel resistor are reliable.
Working condition for me means that I keep old tv sets as original as possible. Repairs are done which are necessary for short operating times (for demonstrations or checks). When I operate such an old set, I do it with a variac. I increase the voltage slowly so the caps were not higher loaded than with full power.
Regarding the RCA 9t-246: according to the schematics for the KCS38-chassis, the horizontal output current should be 110mA. The actual current is maximum 50 to 60mA. The 6BG6 is weak. I will replace it when I get a replacement.
Here are two recent screenshots (no recapping and with weak 6BG6!):
http://bs.cyty.com/menschen/e-etzold...inBetrieb1.jpg
http://bs.cyty.com/menschen/e-etzold...inBetrieb2.jpg
The bluish tint of the screen might depend on the phosphors.
- Eckhard