The 15GP22 Rebuild Project

[ohohyodafarted]

As per the request of another member I am starting a new thread on the 15GP22 project here. I was not able to change the title of the previous thread, so if you havent been reading it here is the link to the thread that started this line of discussion........

http://www.audiokarma.org/forums/sho...d.php?t=173070

Combwork,
First off we are not sure of the leaks in the crt are small or large. Tha is to say we do not know if it takes a long time or if some tubes lose vacuum in a mater of days or hours.

A helium leak detector is used because helium atoms are very tiny. Much smaller than Oxygen or Nitrogen which compose the bulk of our atmosphere, and as a result the tiny helium atom can squeeze through a very small leak more easily.

As for introducing chemicals into the tube....that is essentially what a getter does. The barium getter flash attracts stray molecules left after the tube has been evacuated. This cleans up any stray atoms still floatiing around in the tube after it is evacuated and sealed.

The idea of having a chemical inside the tube to act like a sponge to abosrb the air that leaks in is a non starter. If there were such a chemical, when placed under vacuum the chemical itself would evaporate in the vacuum and the chemical molecules floating around in the tube would have the same effect as atoms of Oxygen or Nitrogen....IE: they would interfere with the flow of electrons from the electron gun and the electrons would never reach the phosphor coating on the screen of the tube.


CUlater:
The tube did get transported via the seller and another AK'r that both went to the same swap meet. The tube is now in my hands and we will attempt to rebuild it on the next trip to Hawkeye.

Bob