[time-nuts] Some more info on the 5065A optical unit

cdelect at juno.com cdelect at juno.com
Mon Nov 27 12:34:52 EST 2017

Made some measurements on a 5065A optical unit.

-There are 3 layers in the magnetic shield.
-There is about 1/8" of insulation between the
 outer and middle, and between the middle and inner shields.
-The C-field winding is wound on a cardboard form that 
 fits tightly into the inner shield.
-There is almost 1/2" of foamed insulation between the C-field
 winding and the cell and oven forms and windings.

Per Poul-Hennings data a 3.25 deg C change of the outer shield
will result in a 1 deg C change in the C-field coil. 

This equates to a 3.4X10-14 frequency shift when not using 
active current drive.

If the outer shield is actively held to plus/minus 1 deg C then 
the shift will be held within plus/minus 1.05X10-14 as long as
the ambient temperature stays within the regulating range of the 
PC liquid cooler.



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