[time-nuts] HP 5061a with a 5060 tube what a education

paul swed paulswedb at gmail.com
Tue Oct 4 21:14:56 EDT 2011

Hello to the group and thanks for the help on this project.
Learned an awful lot in the last 2 hours on the care and feeding of a cesium
beam tube.
Thanks to the experts here.
Unfortunately though this tube 5060 tube is way better then the original 004
that really was dead.
The 5060 tubes in very poor shape also. The flop needs to be >1 and this
tube is .25.
I would imagine I can figure the S/N out, but this actually explains much of
what I am seeing in stability behaviors.

Increasing the C oven has little effect
Increasing the ionizer current does raise beam but it equally raises the
noise exactly equally.
Adjusting the mass spec peaks things.
By gosh I am seeing the ramsey signals. Just not very high. But they are
there on the 25 ua  meter I added.

Further a suggestion to raise the multiplier voltage actually only
contributed to system noise.
Interestingly in raising the noise floor avg and shot noise every now and
So I actually adjusted everything down. Now I have 3 ua beam current
modulation off and 2250 V multiplier.
Carefully peaked the A4 harmonic assembly per the manual.
I have reasonable lock and stability at 8.8 x 10 -12. Or 5 ns drift in 9:22
minutes. The signal definitely wonders around the same point on the scope.

So having built a new CS oven controller and all the rest of the tweaking
and twiddling.
Thanks again everyone for a heck of a education.

Best regards

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