Well I guess "no" because accuracy is the deviation from a known standard (I think) Stability repeatability might be better but you need to consider what the variables might be. Variations in thickness (basically frequency), cut angle (temp coeficient and maybe others), crystal purity (aging, ESR ?). If you average many randomly selected samples you might reduce the level of variablilty of these aspects but would that make them "more accurate"? I doubt that maybe more capable of staying within a given accuracy once adjusted.
I still think the cost effective way is get one "good" one, the best you can afford, characterise it and the make adjustments either calculated or by disciplining. Even an ordinary crystal can be made to perform quite well by adjusting it to track it to something better. Many LF BC stations in Europe are much better than a cheapy (computer grade) crystal and Droitwich and Allouis are locked to a Rb standard and regularly measure against the national standards. A few part in 10^11 costs a couple of hundred dollars.This is 5 orders better than a cheapy crystal. My back of envelope calculation suggest you might need about 100,000 oscillators to achieve this level (ok tell me I'm wrong with the calculation and, as the exam script says, "show you working" .....the red wine was very nice.... I can take it !! :-)) ) Alan G3NYK ----- Original Message ----- From: "Hal Murray" <hmur...@megapathdsl.net> To: "Discussion of precise time and frequency measurement" <time-nuts@febo.com> Sent: Wednesday, May 12, 2010 11:31 PM Subject: Re: [time-nuts] synchronizing a large number of weakly coupled oscillators > > Presumably, a large population of cheap coupled oscillators could be rather > > accurate collectively. > > Why? > > There are 2 main sources of error in inexpensive crystal oscillators. > > The first is the initial manufacturing error. I'd expect crystals made from > the same batch to have similar errors. If you want a large population, you > are going to get most/many of them from similar batches. > > The other is temperature. I'd expect that oscillators of a specific design > to have similar temperature dependencies. Some vendors even include a graph > in their app-notes. > > > It might be interesting to collect oscillators from different vendors and > batches and see what sort of spread you end up with. > > > -- > These are my opinions, not necessarily my employer's. I hate spam. > > > > > _______________________________________________ > 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.
