Help the Museum get its Display Sets Working Again

[Videotechie]

I hope this post motivates someone to save 15" to21" test jigs...

[Penthode]

It looks like the tube connection to the jig 21fbp22 is minus dynamic convergence only?

[Electronic M]

Originally Posted by Penthode

It looks like the tube connection to the jig 21fbp22 is minus dynamic convergence only?

It would have to be since 15GP22 designed chassis lack the correct sweep transformer windings to drive electromagnetic convergence, but at the same time because the electrostatic convergence element of a 15G draws virtually no current the chassis doesn't need a load on it's convergence output wire.

Given a chassis designed to drive a 15G can drive a 21FBP22 sans dynamic convergence, a late 70s early 80s test jig with an inline CRT (which doesn't need electronic dynamic convergence) that has the yoke impedance matching box to allow it to work with a 21FBP22 chassis, should work on a 15GP22 chassis. At that point it becomes a matter of mounting the test jig CRT in the cabinet convincingly and replicating the 15GP22 internal mask so the swap doesn't jump out at you as badly. The difference in phosphor dot shape, pitch, and primary colors will be noticable to someone who has seen a real set as will the curvature of the phosphor dot plate, but if the faux outer glass and inner mask of the 15G are replicated well enough it might take a while to notice with the set off.

I have a good set to try this on while waiting for a 15G to materialize. I have a 19" rectangular delta gun jig I could use as a crude proof of concept (already used it to sub for 21" round sets). If I could get a 13-15" inline jig that would be ideal.

[Videotechie]

It's awesome to see everyone's talent at doing jigs and displays. I'm glad I posted, wasn't expecting such a great result of restorations showing a way around a 15gp22. Thought I would mention just in case finding a set with bad CRT. Is the museum successful on rebuilding these yet.