Moin, On Mon, 20 Mar 2017 17:11:36 -0400 "William H. Fite" <omni...@gmail.com> wrote:
> You are talking about product design, development and optimization, not the > production of a one-off for home use. Since performance standards are > already well established, it is only necessary for the developer to test > the bench built instrument against published standards and determine if > performance is good enough to suit him. Given a sound understanding of the > role of various components in the system, it will be a great deal faster > and easier for the builder to tinker with the one-off then to go through an > extensive process of model development and verification. > > I have spent a good deal of my career doing performance modeling, > verification, and validation in collaboration with other scientists and > also engineers. You describe the process correctly but I think it is > generous overkill for the topic under discussion here. Or have I missed > something in the discussion? Is the desired end result a device for > manufacture and sale? If so, then your approach is right on target. The question kind of started of from how to verify a GPSDO works correctly. My answer to that was to use a known-good GPSDO and an vapor cell Rb standard. Both can be had for quite cheap (<200$ each) or borrowed from a fellow time-nut. With this and a suitable counter (e.g. PICTIC or TICC) one can verify the homebew GPSDO quickly and quantify the result. Chris Albertson injected, that he wanted to do the verification with stuff he could build on his own, not relying on another GPSDO or "expensive" Rb standard. I then showed that, while possible to do so, it takes a lot of effort and time to verify instruments without using known-good references. Yes, you are right that for Joe Average, this is way overkill. For most it will be enough to check whether the GPSDO is within 10-20ns of another GPS (without DO) receiver, and whether the EFC correlates well with the temperature of the OCXO housing. Both checks can be done relatively quickly, given access to a counter, a precise thermometer, and a DMM. But then, this is time-nuts. We love to get the best out of a specific system... even if it takes more effort than just simply buying better equipment :-) Attila Kinali -- You know, the very powerful and the very stupid have one thing in common. They don't alters their views to fit the facts, they alter the facts to fit the views, which can be uncomfortable if you happen to be one of the facts that needs altering. -- The Doctor _______________________________________________ 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.