I think CT-100 could probably easily drive a ~13" inline gun CRT and look good. There were test jigs that could support the CTC-2 that had similar CRTs. It would be a matter of impedance matching the yoke, and selecting a CRT with a compatible specs gun bias, HV and size wise. One could get an appropriate mask off a monochrome set (there are some that are dead ringers for the internal 15GP22 mask) and select an inline gun that would fit inside the factory mounts and fill the added mask. It would be a lot of work to make such a modification in a reversible manner, but I'm convinced it is possible. Given the time and money many collectors have spent on rebuild work for only glimpses of shaky success, I feel this is probably much less difficult of an undertaking to the right people.

If I had a $200 15GP22 based set with a bad or missing CRT you can bet that would be my course of action till a better alternative became feasible.

I think I'd give it a try too. I'm not suggesting modifying a perfectly good set, but let's face it, good tubes are very hard to find. I'd rather see an early set making a picture, even if it required a little "cheating," then having it sitting in the corner of someone's basement because parts were not available. It would be important to save and document original components just in case putting it back to original equipment ever became possible. I doubt it would be easy, but if anyone ever attempts it, I hope they are willing to share information about how they went about it.

Why not, Lee put a square tube into his Royal Sovreign in a reversible manner and we know how good that turned out. I'm sure a square tube could be made to look fairly decent in a Merrill, and I for one would play my CT-100 a whole lot more if I had a disposable tube in it that I didn't have to worry so much about.

Pete originally suggested the use of a VGA tube over a decade ago when he started his quest. I can remember the 14" Matsushita tubes from the VGA/8514 monitors of the early 90's that had wide(r) gamut phosphors that did hot colors very well. These might make for a good stop-gap.

I always thought something like a zenith FTM tube might be viable too...

A real nice find buddy :)

:thmbsp: Indeed ....