Chris There is a low cost solution and I have the input circuit perfect for GPS on a $1 gate array I have boards and am presently using Shera original version. Would like to buy his version 402NE but have not been able to get a response from him. Have repeatedly asked for help on this list for some one to step forward to write the uproc. program. No one. The total material cost would be less than $ 25 PCB included GPS receiver OCXO or RB would be extra. If the FE 5680A with RS232 would be used cost is less than $ 15. There are now PIC's out there that can also do the timing function reducing cost even more but that will take more smarts. Bert Kehren In a message dated 12/4/2012 9:06:26 P.M. Eastern Standard Time, [email protected] writes:
With the price of T-Bolts now higher, does it make sense to build your own GPSDO? What is the simplest phase detecter that could work? I think only that, and then a duouble oven crystal from eBay, a GPS and and Arduido. Yes the Aruino is expensive compared to a bare uP chip but using one, I thin you could build a GPSDO without a PCB and the Arduino's USB connection could be usful for power and logging/control. If ther phase detector where simple enough it could be build on a prototype board the fits on top of the Arduino. There are some other designs but because programming a uP and making a PCB seem to be rare skills that job tends to fall on one person. Anyone can program an Arduino and with out need of a PCB the entire design could be puted on a web page and the replicated with common parts. On Tue, Dec 4, 2012 at 4:01 PM, Bob Camp <[email protected]> wrote: > Hi > > I would guess that HP/Agilent/Symmetricom and Trimble made 100X more > GPSDO's than the next five people in the business combined over the 1995 to > 2005 period. > > Bob > > On Dec 4, 2012, at 10:26 AM, paul swed <[email protected]> wrote: > > > Al > > I like the truetime products. In general easy to understand and last a > long > > time. > > But there never seemed to be that many. Sure they were used in > broadcasting > > and maybe power. But the others like the 3801 and tbolt were used in > telco > > and mobile apps so there were 10,000s turned out and thats why we get > them > > for cheap. I simply never see the truetime dc60 or gps units around. > Though > > I have my stock of dc468 sat clocks. :-) Working. I hacked a goes sat > > replacement 3-4 years ago. > > That said some of the older gps technology is a bit slippery on exactly > how > > good they are. > > So for perhaps amateur purposes they are totally fine but when you start > > comparing to a Tbolt or 3801 various behaviors apear. > > Odetics GPStars as an example slip cycles on purpose. Its a mode you can > > set and by default is how they are set. > > For what they were intended for they are perfect. But at least 1 X10 > poorer > > then other devices. Its not at all broken. It was a general time piece > for > > radio networks. Give or take 500 ms. > > Regards > > Paul > > WB8TSL > > > > > > On Tue, Dec 4, 2012 at 9:58 AM, Al Wolfe <[email protected]> wrote: > > > >> Most of the choices I've seen here mention the Tbolts, 3801, 3805, > etc, > >> but I have never seen anyone mention the TrueTime XL-AK. It advertises > 40 > >> nsec 1 pps. Frequency as 1 x 10-12 per day. I have one and it seems to > work > >> well but have no way to test it against anything else yet. It has four > each > >> 10 MHz sine output that I have been using for house sync for HP3586, > >> HP8924c, PTS160, etc. > >> > >> So how does the TrueTime compare to other GPSDO's? > >> > >> Al, K9SI > >> > >> ______________________________**_________________ > >> time-nuts mailing list -- [email protected] > >> To unsubscribe, go to https://www.febo.com/cgi-bin/** > >> mailman/listinfo/time-nuts< > 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. > -- Chris Albertson Redondo Beach, California _______________________________________________ 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.
