• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

Re-activate getter/save gassy tube

Yesterday monday, re-reading the Radiotron I found this piece, in chapter 1 page 4. It appears that Getter continue working during tube life.
 

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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
 

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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.