because getter is cheaper than high quality anode material.
You only need to re-activate one getter, that will be sufficient.
Trobbins, that is not my work in the link I posted although my version is very similar but using 4 FETs.
I use large gapped ferrite cores for the chokes. I just squeezed as many turns as I could on.
Cheers
Matt
I use large gapped ferrite cores for the chokes. I just squeezed as many turns as I could on.
Cheers
Matt
Reviving an old thread...
At the CHRS radio musuem, this topic came up recently to rescue a CRT showing signs of slight gas content.
Induction heating is used in small parts hardening, annealing and other heat treatment. Kits are available-
https://usa.banggood.com/Geekcreit-...achine-Module-p-1038472.html?cur_warehouse=CN
I've had some previously gassy tubes respond well to being operated at rated parameters over a period of hours (sometimes days); with initial grid current ~4-8 µA coming down to ~1-2µA after operation. Some respond well, some are beyond recovery. Testers used were the Sofia curve tracer and Amplitrex AT1000.
The blowtortch method is too severe and can re-vaporize the getter, depositing on the other elements rendering the tube inoperable. Placing a glass over the tube while under operation makes for a 'mini oven' to help the getter become warm and more active.
Here is an article on getter materials from Electronics magazine, Oct. 1950 (thank you CHRS Library). Useful info on all matters regarding getters.
Regards, Kent, Vintage-Electric-Audio
At the CHRS radio musuem, this topic came up recently to rescue a CRT showing signs of slight gas content.
Induction heating is used in small parts hardening, annealing and other heat treatment. Kits are available-
https://usa.banggood.com/Geekcreit-...achine-Module-p-1038472.html?cur_warehouse=CN
I've had some previously gassy tubes respond well to being operated at rated parameters over a period of hours (sometimes days); with initial grid current ~4-8 µA coming down to ~1-2µA after operation. Some respond well, some are beyond recovery. Testers used were the Sofia curve tracer and Amplitrex AT1000.
The blowtortch method is too severe and can re-vaporize the getter, depositing on the other elements rendering the tube inoperable. Placing a glass over the tube while under operation makes for a 'mini oven' to help the getter become warm and more active.
Here is an article on getter materials from Electronics magazine, Oct. 1950 (thank you CHRS Library). Useful info on all matters regarding getters.
Regards, Kent, Vintage-Electric-Audio
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I have described a regettering device here:
https://www.diyaudio.com/community/threads/a-universal-regettering-station.317055/post-5300124
but for optimum results, it should be used in conjunction with a diffusion pump, or another similar vacuum device which brings the problem to a much higher level of expertise/complication
https://www.diyaudio.com/community/threads/a-universal-regettering-station.317055/post-5300124
but for optimum results, it should be used in conjunction with a diffusion pump, or another similar vacuum device which brings the problem to a much higher level of expertise/complication
I see, thank you. I am not a chemist, but from the paper above, would the outgassing during firing of the getter material be dependent on what type of baruim getter alloy is used (Alba, FeBa, NiBa or CuBa)?
How did your experiments go? Did you notice any patterns?
How did your experiments go? Did you notice any patterns?
I'd suggest a better method to eek out the most from an old getter is to locally insulate the glass region that has the getter splattered on to it, but to leave the remaining glass uninsulated. The aim is to raise the local getter material temperature slightly higher than during normal operation, but not raise the rest of the glass temp or other parts (such as for the 'glass over to top' method) - that then may improve the balancing act of outgassing from glass to getter capture.