Aging is a composite of phenomena sometimes resulting in a negative rate
and sometimes in a positive rate (most common). Some causes that haven't
been mentioned in this thread are the slow release of stress in the
crystalline structure created by shock or temperature excursion, and the
I'm not familiar with the E1938, but the 10811, I believe is one of the
small hi stab units that HP put into their higher end counters. It uses a
single oven where the 103 and 107 used double ovens. Incidentally, the 103
uses a 1 MHz rock and the 107 uses a 5 MHz rock.
-Mike-
At 03:27 PM
At the beginning of the E1938A project, I did some humidity
tests on the 10811. It was fairly sensitive to humidity.
I think I remember being able to get parts in 10^8 shift.
...
At the beginning of the E1938A project, I did a bunch of
characterization of 10811 oscillators. At the Santa
The long term aging rate is due entirely to the crystal,
for all practical purposes, for any well designed oscillator
circuit (or even a mediocre design). The aging of the
crystal is basically not predictable. It's like the famous saying
by J P Morgan when asked what the stock market will do:
It
The best experiment I can think of to prove this is to run the
oscillator in a paper bag until it is stable,
then trickle a flow of dry nitrogen into the bag for a day or two
and watch for oscillator drift as the humidity
in the oven drops to extremely low values.
It is a pity that I do not
At the beginning of the E1938A project, I did a bunch of
characterization of 10811 oscillators. At the Santa Clara
Division, we had first class environmental test chambers
with heating, cooling, humidification, de-humidification,
and nitrogen purge. The nitrogen was also available for
fast
