I am patiently waiting for the code to drive the DAC. Bert Kehren In a message dated 5/7/2012 12:54:54 P.M. Eastern Daylight Time, att...@kinali.ch writes:
On Mon, 7 May 2012 10:30:56 -0500 Bill Dailey <docdai...@gmail.com> wrote: > Does anyone have any knowledge of a simple (just soldering a > few connections and maybe programming a hz/volt rate) PCB for > synchronizing a precision OCXO to a GPSDO? I am trying to improve > short term stability with a high stability OCXO and dont want to > "cut into" my fury and replace the OCXO. I cando it manually but > this seems like it would be nice and desirable for many yet I can't > find anything. I presume it would have to be digital because of the > long time constant. What speaks against a simple design as used in the GPSDO by James Miller[1]? Or if you want a better PLL than just an XOR gate, use a 74x4046. They are still available in DIL, so building a complete PLL is possible on a veroboard. This should be enough if you want to improve the short term stability below 0.1s, where the fury rises above it's long term humb. If you want to flatten down the humb the fury has (the one between a tau of 1s and x*1000s), then you need a very stable OXCO to begin with. Also, then i think the best approach would be to scale down both signals to 1kHz and use a PICTIC II to measure the phase difference between them. Then you can implement the control loop in the PIC of the PICTIC II and drive an _external_ DAC with it. Attila Kinali [1] http://www.jrmiller.demon.co.uk/projects/ministd/manual.pdf -- Why does it take years to find the answers to the questions one should have asked long ago? _______________________________________________ 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. _______________________________________________ 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.