[time-nuts] Mystery hp Oven UPDATE

cdelect at juno.com cdelect at juno.com
Fri Dec 30 13:18:46 EST 2016

Back in June I picked up the mystery oven assy that turned out to be the
oscillator  assy. of an HP 106A.
Since then I have repaired it and another 106B oscillator assy for a
My oscillators main problem was that one of the inner oven windings was
Just for testing I installed an array of resistors on one end of the oven
and surprisingly the unit came up properly! This unit might have been a
prototype or special order as there was no fine mechanical tuning of the
EFC via an internal pot, just the coarse capacitor tuning.
My friends had 3 problems. The temperature adjust pots for both the outer
and inner ovens were open! Also after a couple days of operation with the
new pots the AGC test point wire shorted internally to the supply
voltage. went in and disconnected it internally and routed the test point
via an added wire.
His unit is performing (AD)at 2.0E-13th at 1 and 10 Seconds!
My unit is 3.15E-13th at 32 Seconds and is aging at 4.0X10-11th per day.

Not bad for old tech but HP built them well back then!

Cheers and Happy New Year,


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