Keeping a 15GP22 alive

[miniman82]

A CRT tester is NOT the end all of testing when it comes to vacuum leaks, and you certainly wouldn't be able to tell if there's a discharge glow in the neck from using one- that only occurs with the application of HV from a running chassis. So unless it's made light with a CTC-2 chassis, what the tester tells you is anecdotal. It would be reassuring to see shiney getters in the neck, but at the last convention I went to there was a 15G with ugly ass getters that still worked fine so it's not a written in stone kind of thing.

As far as how to treat it, the museum doesn't have a fancy HVAC system, and the tubes there seem to be holding up fine. As long as you don't ding the weld rim, it's just another vacuum tube in practical terms and you shouldn't treat it like ordnance anymore than any other tube. If it's gonna leak it's gonna leak, nothing you can do about it. That means as long as it has vacuum you should enjoy it, or get it to someone who will enjoy it till it dies. Nothing more sad than a 15G that went to air with little hours on it...

[Red Raster]

Originally Posted by miniman82

A CRT tester is NOT the end all of testing when it comes to vacuum leaks, and you certainly wouldn't be able to tell if there's a discharge glow in the neck from using one- that only occurs with the application of HV from a running chassis. So unless it's made light with a CTC-2 chassis, what the tester tells you is anecdotal. It would be reassuring to see shiney getters in the neck, but at the last convention I went to there was a 15G with ugly ass getters that still worked fine so it's not a written in stone kind of thing.

As far as how to treat it, the museum doesn't have a fancy HVAC system, and the tubes there seem to be holding up fine. As long as you don't ding the weld rim, it's just another vacuum tube in practical terms and you shouldn't treat it like ordnance anymore than any other tube. If it's gonna leak it's gonna leak, nothing you can do about it. That means as long as it has vacuum you should enjoy it, or get it to someone who will enjoy it till it dies. Nothing more sad than a 15G that went to air with little hours on it...

It was time to see if my CT-100 has a working 15GP22, After carful examination I powered up the set with a variac starting at 60 volts slowly advancing the voltage, Around 80 the neon tester lit up brightly as I held it close to the horizontal out put plate cap. Pushed the ac voltage higher, Looking at the screen and then the neck answered the 64,000.00 dollar question, I saw a reddish raster (Go figure) and no purple glow in the neck. with full deflection and the scan lines in focus.
This was just a short duration test without signal and now the chassis will under go a thorough re cap job before it gets plugged in again. The long and rewarding journey has started.


It's alive and will be a working set after restoration.


This is the chassis I have to work with I have yet to clean it.


All of the tubes check good and they are the factory originals.


62 years of dust.


These selenium rectifiers are good and allowed for a successful first
light test.

[Phil Nelson]

Man, apart from a little dust, that's a mighty clean looking set.

Take your time and enjoy the project. Most collectors don't get a chance to restore more than one of these!

Regards,

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html

[kvflyer]

Congratulations!! I would be remiss if I didn't say that I was envious. Enjoy that set. Not too many people out there understand what this is all about... especially what the 15GP22 is all about. I didn't until a few years ago...