Hi Scott, I do understand the reasons that these users want this quality of output. It's who these users are, what fields, industries, etc, that I didn't quite understand. Bob ----------------------------------------------------------------- AE6RV.com
GFS GPSDO list: groups.yahoo.com/neo/groups/GFS-GPSDOs/info From: Scott Stobbe <scott.j.sto...@gmail.com> To: Bob Stewart <b...@evoria.net>; Discussion of precise time and frequency measurement <time-nuts@febo.com> Sent: Sunday, December 18, 2016 8:22 PM Subject: Re: [time-nuts] 1PPS users? Part of the reason 1PPS needs to be so clean is because you are continuously integrating phase noise of the LO (hopefully an OCXO). While 10 uS is pretty trivial off a gps receiver. Without gps, 10 us over 24 hrs with a plane jane AT-cut crystal subject environmental dynamics becomes ludicrous. More than likely the short term stability of GPSDO is cleaner than it needs to be for many applications, but that is so holdover over an hour or day remains reasonable. On Sun, Dec 18, 2016 at 6:16 PM, Bob Stewart <b...@evoria.net> wrote: One thing I've never really understood is who actually uses the high-quality 1PPS output from a GPSDO. I have spent a lot of time, effort, and money on developing my GPSDO without a whole of thought to the user base. It was just a quest for the best result I could obtain with a particular technology. The frequency standard users was a no brainer. Everyone who wants a frequency standard eventually understands they need to get a GPSDO, or an Rb, or a Cs. And that's all I thought I had: a good frequency standard. And then Tom prodded me a bit and showed me the shortcomings of what I was doing, and I did something about it. So, if an NTP user can get his time fix directly from a noisy receiver, who actually needs a time-accurate, low jitter 1PPS pulse? Bob - AE6RV ----------------------------- ------------------------------ ------ AE6RV.com GFS GPSDO list: groups.yahoo.com/neo/groups/ GFS-GPSDOs/info ______________________________ _________________ 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.