Need an 11SP22 for a 1967 portacolor

[Turle]

So a friend of mine recently gave me a ‘67 porta, and it works aside from an unfortunate g1 short that refuses to clear no matter how many times it’s zapped.

So I am posting here in hopes of finding someone who has one they can sell to me. It doesn’t have to be brand new or anything, as long as it has useable emissions and no shorts it’s alright with me. Thanks

[timmy]

I have a small color tube thats maybe what your looking for but no promises I’ll check the number on the tag. Is there another number for the same tube but a later one like maybe 1970.

[timmy]

Ok well I thought it may have been the right one but it’s a matsushita tube color but measures 13 diagonal it’s old since it has the dot phosphors.

[reeferman]

I know this sounds crazy but it's worth a try and costs nothing.

When we had a nasty heater to cathode short that wouldn't budge, we would take the (live) 2nd anode and run it around the CRT pins. Surprisingly it worked quite often.

Never tried it on G1 short, but what's to lose?

[Electronic M]

If the short (G1-K?) persists without heater voltage applied it might be worth while to take something like a 20+ Amp low voltage lab power supply with current regulation, connect it between the two shorted elements with the heater completely cold and see if you can burn the short open with high current (a supply with current regulation would allow you to creep up on the fusible portion of the short and in a dark room give you warning via red glow if something else was about to burn open). If the heater is cold then theoretically there'll be no cathode coating emissions and no cathode damage and all the current will be through the short....Granted it's gambling on the short having less material than the rest of the internal gun structure and if that 50-50 gamble loses and you don't see glow in the wrong place in time to stop you either burn open an internal connection to the cathode or an internal connection to the grid.

If the tube is completely unwatchable it's a gamble I'd be willing to take assuming you've tried all gentler methods first.

[Turle]

Originally Posted by Electronic M

If the short (G1-K?) persists without heater voltage applied it might be worth while to take something like a 20+ Amp low voltage lab power supply with current regulation, connect it between the two shorted elements with the heater completely cold and see if you can burn the short open with high current (a supply with current regulation would allow you to creep up on the fusible portion of the short and in a dark room give you warning via red glow if something else was about to burn open). If the heater is cold then theoretically there'll be no cathode coating emissions and no cathode damage and all the current will be through the short....Granted it's gambling on the short having less material than the rest of the internal gun structure and if that 50-50 gamble loses and you don't see glow in the wrong place in time to stop you either burn open an internal connection to the cathode or an internal connection to the grid.

If the tube is completely unwatchable it's a gamble I'd be willing to take assuming you've tried all gentler methods first.

Unfortunately it’s behaving more like grid leakage almost, where it starts off fine but after it heats up for a bit the short creeps up to the point where the whole screen goes red.

[Electronic M]

Originally Posted by Turle

Unfortunately it’s behaving more like grid leakage almost, where it starts off fine but after it heats up for a bit the short creeps up to the point where the whole screen goes red.

You still might be able to do it... Especially if it takes longer to clear than the cathode does to loose emissions after power off, just a bit riskier that way.