); SAEximRunCond expanded to false Errors-To: [EMAIL PROTECTED] RETRY I am confused by the PLL vs. FFL lock discussion. Does this concern the Schera board vs. the VE2ZAZ methods of time base discipline? Can someone share their thoughts on the subject? Thanks! 73 de K4TEU (Tom(
-----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Bruce Griffiths Sent: Saturday, September 01, 2007 10:19 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] GPSDO Question ); SAEximRunCond expanded to false Errors-To: [EMAIL PROTECTED] RETRY JOS Earthlink wrote: > 73 de K1JOS (Jerry) > CCA #11906 > CRA #1777 > > > > > > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] > Behalf Of [EMAIL PROTECTED] > Sent: Saturday, September 01, 2007 12:00 PM > To: [email protected] > Subject: time-nuts Digest, Vol 38, Issue 1 > > > ); SAEximRunCond expanded to false > Errors-To: [EMAIL PROTECTED] RETRY > > Send time-nuts mailing list submissions to > [email protected] > > To subscribe or unsubscribe via the World Wide Web, visit > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > or, via email, send a message with subject or body 'help' to > [EMAIL PROTECTED] > > You can reach the person managing the list at > [EMAIL PROTECTED] > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of time-nuts digest..." > > > Hi Group, > > I just recently completed a GPSDO inside a HP5328A. I was going to use the > Schera board but opted for the VE2ZAZ. At first I tried to cannibalize the > HP5328A's internal power supply for either the +/-15VDC or +5/-5.2VDC supply > but I discovered the hard way that they would not supply enough current > (burnt out CR1 and Q7) or the supplies would not be well regulated. I opted > therefore to include inside the case a +/-12VDC swtiching supply powered > externally by a 24VDC wall wart. From the +/-12VDC dual supply I cleaned up > the rails with an L7805 and L7905. I was able to bring out to the the rear > panel the 10Mhz and 5Mhz references plus the SMA GPS antenna connector. On > the side panel I put in a momentary pushbutton switch to reset the GPS if > needed plus a DB9 RS232 for serial communicatiosn with either the GPS using > software like VisualGPS) or to monitor the VE2ZAZ board status. A simple > DPDT switch next to the DB9 connector controls the serial selection. I have > complete pictures if anyone is interested and it works very nicely. > > Jerry > K1JOS > > > _______________________________________________ > 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. > > Jerry It is amusing/distressing to see that the myth that using an FLL to lock an oscillator to the PPS output of a GPS receiver is a good approach still persists. The optimum solution is a phase lock loop. Whilst building an FLL is instructive/educational, if you want the best GPSDO performance you should really use a PLL. Bruce _______________________________________________ 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.
