On Thu, Apr 10, 2014 at 10:55 AM, Charles Steinmetz <[email protected]>wrote:
> > Why even try to discipline an OCXO before it's warm? Just leave the > control loop off for a predetermined time at startup. You can light up a > bright red "unlocked" LED, and even inhibit the 10 MHz output until lock is > achieved if you want. > Even if you wait long enough you still need to set the DAC to "something" as a first try. What if your first guess is off by a large amount. The answer is not to guess better because you still need some way to determine if the guess is correct. > > Alternatively, you could figure out the EFC voltage needed to zero the > cold oscillator How to do that? Can you write code to do this without counting overflows? You can be off by 256 cycles and never know it. Let's assume someone is building a GPSDO because they need a frequency reference and don't have one. A good assumption, I think. How could such a person "figure out the EFC voltage needed" with out either coining cycles? I'm thinking about turning the overflow counter off after lock. But without one I think we have a chicken and egg problem where you would need an accurate frequency reference to build a GPSDO. -- Chris Albertson Redondo Beach, California _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
