[time-nuts] LTE-Lite module
Tom Van Baak
tvb at LeapSecond.com
Mon Oct 20 23:42:01 UTC 2014
To add to Bert's note...
Realize that for a GPSDO, (linear frequency) aging-per-day is irreverent, almost by definition. What matters is phase noise and short-term stability, neither of which you can possibly fix with disciplining against GPS. GPS takes care of the rest.
Long-term stability can be critical for non-GPS applications, which is why oscillators with daily aging rates in the -11's and -12's are so amazing.
Consider this: if you want to run your bench with a clean 10 MHz source, stable to 11 or 12 digits and accurate to 9 digits -- you may be much better off with a free-running, stand-alone OCXO with an aging rate down at 1e-11/day than using a GPSDO/TCXO. To maintain accuracy of your OCXO just re-tune your OCXO *once a year*. Aside from ADEV plots, this is another way to appreciate how amazing some OCXO are, any why many of us still troll eBay for high-stability, low-noise, low-drift quartz oscillators.
----- Original Message -----
From: "Bert Kehren via time-nuts" <time-nuts at febo.com>
To: <time-nuts at febo.com>
Sent: Monday, October 20, 2014 4:01 PM
Subject: Re: [time-nuts] LTE-Lite module
Allow me to clarify.
I started out with 7 MV 89 one of it a total loss. The remaining 6 after 3
month + burn in show better than 1 E-11 aging per day, 2 closer to 5 E-12.
Only two have been tested for ADEV and are close to 1 E-12, 2X not 10 X.
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