Yikes! Another CT-100 !

[jeyurkon]

Originally Posted by WA3WLJ

Isn't there a small copper tube nipple under or around the Black pin base?
If the filaments are good and then the base carefully removed; couldn't one vacuum pump the tube back down to around 1 X 10-5 or 1 X 10-6 ,and after applying VAC-U-Seal over the leak paths while still pumping (of course) . But then again you would only tap into this tube nipple if you knew the tube had already gone to air.

If I understood John and Bob correctly, most of them haven't gone completely up to air, but are gassy. I think you could tap into the line without breaking the residual vacumm and reach the pressure range you mention.

You need much better vacuum than this for long life. If rebuilding options were available I'd rather go that route if I had one that didn't work, rather than expending resources on a repair that wouldn't last long.

John

[jr_tech]

Originally Posted by jeyurkon

If I understood John and Bob correctly, most of them haven't gone completely up to air, but are gassy. I think you could tap into the line without breaking the residual vacumm and reach the pressure range you mention.

You need much better vacuum than this for long life. If rebuilding options were available I'd rather go that route if I had one that didn't work, rather than expending resources on a repair that wouldn't last long.

John

I wonder if a small turbomolecular pump would fit in the base of a CT-100, I think they are good for 10-8 or so.

jr

[jeyurkon]

Originally Posted by jr_tech

I wonder if a small turbomolecular pump would fit in the base of a CT-100, I think they are good for 10-8 or so.

jr

Or an ion pump so you wouldn't have to deal with the sound of the backing pump.

I think some of the high power klystrons basically have an ion-pump built into them.

John