[time-nuts] GPS W/10KHz

Chris Albertson albertson.chris at gmail.com
Sat Feb 8 12:33:08 EST 2014

On Sat, Feb 8, 2014 at 3:44 AM, Volker Esper <ailer2 at t-online.de> wrote:

> you don't need 10kHz to build a GPS disciplined oscillator. GPSDOs are
> build with control loop response times in the range of some hours, so
> the loop will be absolutely happy with a 1PPS input.

Of course you are correct.  Most GPSDOs are driven with a 1Hz pulse.  But I
think maybe the OP is not building just any GPSDO but maybe he is looking
to repair a specific GPSDO that is designed to use the old (and now rare)
Rockwell GPS.      If that is the case he needs the old Rockwell or needs
to redesign his system.

If you are starting from scratch to build a new GPSDO it's easier now.  All
you need is some kind of a phase detector (74HC4046 ?) and a small uP that
has a good built-in DAC.  The uP checks the phase once per second and
adjusts it'sDAC accordingly.

Chris Albertson
Redondo Beach, California

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