Quote:
Originally Posted by old_tv_nut
See this video of Scotty at Hawkeye applying the high voltage at 1:16:00 and following.
No name is given for the device except a high voltage transformer.
https://www.youtube.com/watch?v=PFnWYe5MzrY
I also seem to recall a name attached to the handheld device you're describing, but I don't remember it, even though we had one in the lab at Zenith. |
There was a quack medical device called "Violet Ray" that was a small HV operated hand held HV transformer with some kind of buzz coil in it that (it originally would drive a light up gas tube) some collectors use them to check for gas in early color CRTs (they replace the tube with a metal spike) but from having one I can tell you that some good non-gassy tubes light up just like bad known gassy ones do so it's not a spectacularly accurate test.
Quote:
Originally Posted by Chris K
Thanks for offering to do that. I'm hoping by October we'll have a good idea of what kind of shape the equipment is in and how good we are with manipulations. I hope we can find some guns appropriate for 10BP4 and 12LP4 tubes but since they are the oldest magnetic focus commercial CRTs, the availability of NOS guns is probably scarce.
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The basic 10BP4 guns were carried through into the mid 50s when magnetic focus slowly disappeared. It should be possible to rebuild with an electrostatic focus gun and remove the focus coil from the neck area of the TV and have a usable tube....Vice versa you could add a PM or EM focus magnet and make what originally was a electrostatic focus tube work in the same set with a new magnetic focus gun.
Both the 10BP4 and 12LP4 are common enough (just about everything used them for the better part of 4 years and broadcast monitors used compatible types into the 60s) that supply shouldn't dry up any time soon (there are enough low desirability models out there with ruined cabinets as donors) but on the flip side there are many oddball screen sizes that were only used in a few sets where it a tube isn't on a shelf somewhere you might have to wait years for a replacement.
At risk of repeating myself I believe the way forward on the gun issue is to source new heater-cathode and getter assemblies and weld them to existing guns. This is what RACS did on the 15GP22 they rebuilt since a replacement gun wasn't available then. While it's a little fiddly getting grid cathode spacing right (and possibly cathode diameter) and there would be some learning curve spot welding, it's far simpler and there's far fewer variables than making a new gun and it doesn't present the challenge of requiring a maker to either find lost documents or reverse engineer an old gun.