); SAEximRunCond expanded to false Errors-To: [EMAIL PROTECTED] RETRY Said -
I only met him once, but, I thought his name was Dave - Mike Mike B. Feher, N4FS 89 Arnold Blvd. Howell, NJ, 07731 732-886-5960 -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED] Sent: Monday, August 20, 2007 3:30 PM To: time-nuts@febo.com Subject: Re: [time-nuts] Fury Realhamradio listing ); SAEximRunCond expanded to false Errors-To: [EMAIL PROTECTED] RETRY In a message dated 8/20/2007 02:26:09 Pacific Daylight Time, [EMAIL PROTECTED] writes: >A side effect of the 5 sample average is the opportunity to reduce the >effective saw tooth error to 1/5 when the GPS LO is adjusted about 0.4 Hz >high. This causes the GPS pulse position to advance about 20ns every second >and repeat every 5 seconds creating a more stable average. >Enjoy >Peter Hi Peter, thanks for the info. Not sure you can say 5 sample averages result in 1/5 the error. I think you have to use 1/sqrt(5) if it's Gaussian noise. Well, a hanging bridge is hardly Gaussian, so maybe you are right. I talked to Paul Allan (Mr. Allan deviation) and Jack Kusters who both worked on the Z3816A development, and while they don't remember specifics, they did think that the unit has a 1ns TI measurement resolution per second. It would be interesting to use a highly-stable 1PPS source without sawtooth (another Z3816A, or a Rubidium source etc) and replace the GPS receiver 1PPS and see how the algorithms handle this... The question is: how much short to medium term stability improvement can be achieved with the best available GPS receivers (say an M12M)? Or does it not matter at all as Tom explains, since the loop averages out any STS errors? We do see differences in our Fury GPSDO when it is running using an M12+ versus an M12M (all else being the same), the M12M receivers seem to have significantly less diurnal pertrubations than the M12+ (well, we are talking <+-10ns over a day anyways for the M12+). bye, Said ************************************** Get a sneak peek of the all-new AOL at http://discover.aol.com/memed/aolcom30tour _______________________________________________ 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. _______________________________________________ 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.