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To: time-nuts@febo.com
Cc: time-nuts@febo.com
Subject: Re: [time-nuts] Thoughts on Cs tube failure modes
Date:Sun, 30 Nov 2008 18:35:27 +
John,
What you describe with the ion pump curent is normal if the tube has been
powerd off for a long time.
Th mainframe
What you describe could be whiskers growing in the ion pump.
They do not affect the pumping until they grow big enough to load the
supply past its current capability.
You can sometimes remove them using a hand held brush discharge tester.
(Remove tube from chassis before doing this!)
I would
: [time-nuts] Thoughts on Cs tube failure modes ([EMAIL PROTECTED])
Date:Tue, 2 Dec 2008 20:13:22 +
What you describe could be whiskers growing in the ion pump.
They do not affect the pumping until they grow big enough to load the
supply past its current capability.
You can sometimes
I recently found a tube from a 5062C on eBay in unknown condition for not
*too* much money, and thought it would be interesting to power it up on the
bench. Once I got it and saw the 19xx-prefix serial number, I wasn't too
optimistic, since it could potentially be 25 years old or more. Things
John Miles wrote:
I recently found a tube from a 5062C on eBay in unknown condition for not
*too* much money, and thought it would be interesting to power it up on the
bench. Once I got it and saw the 19xx-prefix serial number, I wasn't too
optimistic, since it could potentially be 25 years
John,
What you describe with the ion pump curent is normal if the tube has been
powerd off for a long time.
Th mainframe normally would turn the oven and ionizer filaments off when
the ion pump current pegged.
After minutes (can be quite a few minutes) the ion pump current will drop
as it pumps
Hmm! I appreciate the tip. I'll confess it didn't occur to me to try to
force more current through the ion pump. The supply I was using was limited
to about 300 uA, but I took your advice and tried a beefier one, set to 3
kV. As I increased the current limit from 0 towards 5 mA, the ion-pump
