God eftermiddag, On Tue, 8 Dec 2015 23:45:52 +0100 Magnus Danielson <mag...@rubidium.dyndns.org> wrote:
> If you would setup essentially a micro-stepper design, such as those > being used for cesium and hydrogen masers, but maybe adapted to a > hobbyist needs and with straight-forward way of building and tune-up, > then we could alter the design pattern. The phase-noise and long term > stability issues is clear. It doesn't look too difficult to crank something out within a rainy weekend or two. But I am most likely underestimating the amount of work :-) > Doing control loop using a phase-stepper is a little bit different, and > has a few minor design-challenges, but once mastered is essentially the > same. EFC or C-field control then becomes more an initial setup. What makes the control loop different (beside that you control phase and not frequency, and thus have to integrate)? > An alternative approach divider wise is to use re-generative dividers. > For Rick's approach there would be a number of these at the same > frequency (nominally), so the same design-pattern would apply. However, > that would only be meaningful if you need really need to keep the noise > down. Yes, I thought about that as well, the problem here is that the low noise mixers designs use transformers, which make everything bulky and expensive (the usual suspects cost 2USD/piece and use about 1cm^2). The one design that comes to mind that doesn't need transformers is the tripple Gilbert-Cell design, but that might be higher in noise. (Heck, i should just sit down and do some noise calculations) Additionally, there is a need for relative steep filters for 667kHz Attila Kinali -- It is upon moral qualities that a society is ultimately founded. All the prosperity and technological sophistication in the world is of no use without that foundation. -- Miss Matheson, The Diamond Age, Neil Stephenson _______________________________________________ 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.