Lux, Jim (337C) wrote:
Or, as it was explained to me, the magnetic field causes the holder to move,
which puts a mechanical stress on the crystal, which changes the frequency.
Just how much depends on the details not only on the holder parts but
also how the crystal is mounted. The extreme case here is the BVA
crystals, where the oscillating crystal piece is not held by traditional
holders, but with an extended part of the same crystal, which should
almost completely remove the magnetic coupling (to the crystal).
SC cut crystals is expected to behave much better than AT cut in this
respect, as they should compensate for mounting stresses to a much
better degree.
And an AC field can induce a voltage in a loop (i.e. The wires going to the
crystal), which then moves the crystal, etc.
Indeed.
SC-cut crystals is however sensitive to E-fields and a static DC field
will shift the frequency. This is also part of the frequency jump
mechanism, as the cleanness makes point charges on the crystal can stay
for very long time, but when a single ion atom leaves, the E-field
changes and the jump is a fact.
I beleive other cuts also have E-field sensitivity, but I can't recall
seeing any specifics on it, but I haven't really looked either.
Limitless things to worry about in extreme time-nuttery...
Yes, it is an effective hobby in that you can't stop... :)
Cheers,
Magnus
_______________________________________________
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
