On Mon, 17 Jul 2017 10:24:42 -0700 Brooke Clarke <bro...@pacific.net> wrote:
> The Quantic Timing GPS receiver makes use of patent 5440313 > which results in a 48 bit DAC. How does this idea compare? > http://www.prc68.com/I/Q5200.shtml > https://www.google.com/patents/US5440313 > PS the above patent cites 4582434 i.e. the Heathkit GC1000 HFDO. Figure 4 is nothing but an elaborate way of describing a PWM generator. Figure 5 uses an DDS to generate an offset frequency relative to the GPSDO output and uses that to phase lock the GPSDO to an external frequency reference . I don't think that Fig 5 gives any advantage over a proper DAC. If anything, I would guess the spurs of the DDS generate a lot of noise on the EFC. It's advantage is, though, that you can lock the 10MHz on any reference that is close to 10MHz (or far off, for that matter) and use the stability of that reference for the output of the GPSDO. There are IMHO better ways to achieve that, though. Attila Kinali -- You know, the very powerful and the very stupid have one thing in common. They don't alters their views to fit the facts, they alter the facts to fit the views, which can be uncomfortable if you happen to be one of the facts that needs altering. -- The Doctor _______________________________________________ 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.