Mxsmanic wrote:
How sensitive are these CSACs to other environmental variables? What about
shock, or position? Are they robust enough to be used in wris****ches and
portable timepieces (disregarding cost)?

Which reminds me: why are there no wris****ches that use GPS just for a time
reference, without the geolocation functions? Or are there? Seems like there'd
be a market for such watches to replace "radio-controlled" watches depending
on WWVB and the like, if the price isn't too high. They wouldn't need a CSAC,
although that would be a nice bonus.

No GPS unit is low-power enough to be used as a pure wris****ch, where a
single button battery is supposed to last for years.

You might get away with a very good crystal plus a GPS that only wakes
up once (or a few times) per day or so, in which case you have made
yourself a very expensive chronometer. :-)

Instead of spending power on an oven for a TCXO you could use the Garmin
approach of a tiny temperature sensor (_very_ low power) plus an
automatically calibrated temp adjustement table for the XO.

Terje

--
- Terje.Mathisen at tmsw.no
"almost all programming can be viewed as an exercise in caching"