----- Original Message ----- From: "Tom Van Baak" <[EMAIL PROTECTED]> To: "Discussion of precise time and frequency measurement" <[email protected]> Sent: Thursday, February 14, 2008 8:53 AM Subject: Re: [time-nuts] GPS Locked and Unlocked Performance Comparison
> Hi Said, > > The Miller design doesn't support holdover. You can either > run it free (using JP1, see earlier mail) or run it GPS-locked. > I think the PLL is all of one gate and an RC filter so there's > nothing to "hold" the EFC. See his web site for details. > > Right, if you pull the GPS antenna the unit quickly goes way > off frequency. This is a side-effect of its minimalist design. > Remember he calls it the "10 MHz Simple GPSDO". So it's > not a GPSDO one would sell to telecom. But it works fine for > non-critical use. > > Yes, the performance is nice. I've tested two earlier simple > GPSDO prototypes from Miller and they each get better. I'll > have a better understanding when I make the measurements > Bruce suggested. There's a published design very similar to James Millers from Andy Talbot- http://www.frars.org.uk/cgi-bin/render.pl?pageid=1285 I think they were both published about the same time originally. He uses a 4046 for the phase detector and suggests a decent OCXO but otherwise very much the same. DaveB, NZ _______________________________________________ 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.
