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Roger and Ute Brown September 18th 04 06:04 AM

833A Question
 
I have an 833A tube which I will use for a special project. I notice,
however, that it seems to have very small flakes deposited inside the
envelope. From what I surmise, they apparently jarred loose from the
"getter." Has anyone run across this phenomena before - and more
importantly, could I expect the tube to function OK with these deposits?

Roger, KL7Q



Steve September 18th 04 03:42 PM

If the flakes are from the silver area on the inside of the envelope
opposite the getter, your tube has lost its vaccuum. Not good for much
except for display purposes.

Steve

Roger and Ute Brown wrote in message
...
I have an 833A tube which I will use for a special project. I notice,
however, that it seems to have very small flakes deposited inside the
envelope. From what I surmise, they apparently jarred loose from the
"getter." Has anyone run across this phenomena before - and more
importantly, could I expect the tube to function OK with these deposits?

Roger, KL7Q





Scott Dorsey September 19th 04 01:28 PM

Roger and Ute Brown wrote:
I have an 833A tube which I will use for a special project. I notice,
however, that it seems to have very small flakes deposited inside the
envelope. From what I surmise, they apparently jarred loose from the
"getter." Has anyone run across this phenomena before - and more
importantly, could I expect the tube to function OK with these deposits?


No, that's metal that has outgassed from the hot cathode and plate. It
happens when the tube gets some hours on it. Eventually it will fail.
You may well have a huge amount of life on it before it does, though.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

cpstelecom.co.uk September 19th 04 07:47 PM

The tube should be still OK, just make sure that none of the bits are caught
up between the cathode and grid, I have a couple of 813's with the same
problem and they are still working fine for the last 2 years.

Steve h

"Roger and Ute Brown" wrote in message
...
I have an 833A tube which I will use for a special project. I notice,
however, that it seems to have very small flakes deposited inside the
envelope. From what I surmise, they apparently jarred loose from the
"getter." Has anyone run across this phenomena before - and more
importantly, could I expect the tube to function OK with these deposits?

Roger, KL7Q




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