Hi Magnus et al - You startled me with "Garners PLL book"! I knew what you meant but also that the name was not quite correct and I was racking my brain.
It is Floyd Gardner's Phaselock Techniques, a classic. The Third edition was recently released. http://www.amazon.com/Phaselock-Techniques-Floyd-M-Gardner/dp/0471042943 Very readable. John Allen K1AE, Bolton, MA M: 508 361-6229 -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Magnus Danielson Sent: Saturday, March 10, 2012 11:19 AM To: [email protected] Subject: Re: [time-nuts] DIY GPS-DO On 03/10/2012 04:11 PM, Azelio Boriani wrote: > Ah, yes, now I see: you suggest to keep track of the FOM and DOP from > message #21 and move the oscillator to minimize them. Interesting and > doable. The oscillator time and frequency bias is already being supplied, so no need for a PICTIC to measure. Just read the message coming down the serial line and use that for steering. > Interesting, as usual, the references by Attila: I'm searching for the book > by Roland E. Best. It's a fairly good startingpoint, but I also find Garners PLL book a dense and highly readable book. Cheers, Magnus > On Sat, Mar 10, 2012 at 3:59 PM, Attila Kinali<[email protected]> wrote: > >> On Sat, 10 Mar 2012 14:07:33 +0100 >> Filip Ozimek<[email protected]> wrote: >> >>> could you recommend me a good project of GPS-DO? I've got a GPS module >>> with 1PPS output and a 20 MHz VCXO. >>> As I understand to do a phaselock to 1 PPS signal one must build some >>> kind of digital PLL. But I'm not sure >>> how to calculate a correction signal to the VCXO and how to test such >>> a disciplined oscillator. >> >> Start with reading the following documents: >> >> [1]: >> James Miller's GPSDO based on a 10kHz output of an Jupiter GPS unit. >> It is by far the most simple system i've seen sofar. It's mostly analog >> (beside the dividers) and uses a XOR based PLL for the FEC generation. >> >> [2]: >> A GPSDO around a PIC16C73 from Brooks Shera. It is basically what you >> want to do. >> >> [3]: >> A GPSDO that is based on an FLL (frequency locked loop) by Betrand Zauhar. >> Similar to the one above, but because it's using an FLL instead of an >> PLL it has a slight frequency offset (instead of a slight phase offset) >> >> You also want to read: >> "Phase-Locked Loops" by Best. >> The best book on PLL's i've found. Explains everything you need to know. >> >> [4]: >> The PICTIC as an example how to build a time interval counter that is >> good to<1ns (see [5] for information on PICTIC performance). >> >> Depending on the stability and accuracy you want to accheive, it might >> also be possible to use one of the modern uCs that run with>100MHz >> clocks and use its internal timer as TIC. It will give you an measuremnt >> accuracy better than 10ns, which is in the range of the width of a good >> timing GPS receiver (see [6]), this would simplify your circuitry >> quite considerably. >> >> Over the past years, there have been numerous discussions on GPSDOs >> on this mailing list. I suggest you walk trough the archives and >> read some of them. >> >> >> HTH >> >> Attila Kinali >> >> [1] http://www.jrmiller.demon.co.uk/projects/ministd/manual.pdf >> [2] http://www.rt66.com/~shera/QST_GPS.pdf >> [3] >> http://ve2zaz.net/GPS_Std/Downloads/VE2ZAZ_GPS_Derived_Std_QEX_09_10_2006.pdf >> [4] http://www.ko4bb.com/dokuwiki/doku.php?id=precision_timing:pictic >> [5] http://www.ke5fx.com/pictic.htm >> [6] >> http://www.u-blox.com/images/downloads/Product_Docs/Timing_AppNote_(GPS.G6-X-110 07).pdf >> >> >> -- >> Why does it take years to find the answers to >> the questions one should have asked long ago? >> >> _______________________________________________ >> 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. >> > _______________________________________________ > 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. _______________________________________________ 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. _______________________________________________ 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.
