Re: [time-nuts] Cesium Oscialltors and Low Phase Noise Frequency Standard
Cambridge University Press, which is a non-profit company. I am unsure of the relevance of the above statement but, being pedantic (as befits time-nuts): Cambridge University Press is part of the University of Cambridge [see http://www.admin.cam.ac.uk/univ/so/so_statj.pdf], and the University of Cambridge is a common law corporation, being a corporation by prescription consisting of a Chancellor, Masters, and Scholars who from time out of mind have had the government of their members and enjoyed the privileges of such a corporation. ... The University is now authorized by the Lord Chancellor to act in relation to charitable, ecclesiastical, and public trusts as a trust corporation. [http://www.admin.cam.ac.uk/univ/so/so_prelims.pdf] Chris G3RSE ___ 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.
Re: [time-nuts] Cesium Oscialltors and Low Phase Noise Frequency Standard
Martyn, designing a Cs standard is not the job for a single man, yet I might help you to find frustrated scientists who worked on a Cs project (some 10 years ago I took a part in a project, designing damn impossible precision electronics). About the noise of your quartz oscillator, not bad. Yet: Oscilloquartz 8607 has -128.5 dBrad^2/Hz at 1 Hz offset, at 5 MHz, which scales to -122.5 at 10 MHz, thus -125.5 dBc. Off the shelf, may have some delay. Rakon has -132 dBrad^2/Hz at 1 Hz offset, at 5 MHz, which scales to -126 at 10 MHz, thus -129 dBc. Small production for space, not sure you can actually buy it. In your oscillator, is the power dissipated by the quartz of 40 microwatts? Can you send a spectrum? I am getting great fun in reverse engineering the oscillator noise. The noise I mean, not the oscillator. This takes some 40-50 pages of my forthcoming book on phase noise and frequency stability in oscillators. You can't enter an order number, you must wait for Cambridge University Press, which is a non-profit company. Cheers, Enrico On 6 Dec 2007, at 15:12 , Martyn Smith wrote: Hi, Is there anyone out there clever enough to design me a cesium frequency standard?? There's only two manufacturers that I know of and there's room for another supplier. Also you may be interested to read we have just developed what we believe to be the worlds lowest close-in phase noise 10 MHz oscillator. It makes -121 dBc/Hz @ 1 Hz. Noise floor is only -162 dBc/Hz at the moment, but we are working on reducing this a further 5 to 10 dB. Enter your order number here.. Best Regards Martyn This Email is from: Martyn Smith Precision Test Systems LTD Tel: +44 (0) 1245 329608 Email: [EMAIL PROTECTED] Web: www.ptsyst.com ___ 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. Enrico Rubiola professor of electronics web:http://rubiola.org e-mail: [EMAIL PROTECTED] FEMTO-ST Institute 32 av. de l'Observatoire 25044 Besancon, FRANCE voice: +33(0)381.853940 (E.Rubiola) voice: +33(0)381.853999 (switchboard) fax:+33(0)381.853998 ___ 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.
Re: [time-nuts] Cesium Oscialltors and Low Phase Noise Frequency Standard
Why do you say there's room for another supplier? 5 years ago there were 3 suppliers, but Agilent sold out to Symmetricom. What unmet need are you proposing to fill? What is the short term stability (sigma-sub-y-of-tau) of your world class oscillator? Rick Karlquist (RF designer for the 5071A Cesium standard) Martyn Smith wrote: Hi, Is there anyone out there clever enough to design me a cesium frequency standard?? There's only two manufacturers that I know of and there's room for another supplier. Also you may be interested to read we have just developed what we believe to be the worlds lowest close-in phase noise 10 MHz oscillator. It makes -121 dBc/Hz @ 1 Hz. Noise floor is only -162 dBc/Hz at the moment, but we are working on reducing this a further 5 to 10 dB. Enter your order number here.. Best Regards Martyn This Email is from: Martyn Smith Precision Test Systems LTD Tel: +44 (0) 1245 329608 Email: [EMAIL PROTECTED] Web: www.ptsyst.com ___ 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.
Re: [time-nuts] Cesium Oscialltors and Low Phase Noise Frequency Standard
Martyn Smith wrote: Hi, Is there anyone out there clever enough to design me a cesium frequency standard?? There's only two manufacturers that I know of and there's room for another supplier. Also you may be interested to read we have just developed what we believe to be the worlds lowest close-in phase noise 10 MHz oscillator. It makes -121 dBc/Hz @ 1 Hz. Noise floor is only -162 dBc/Hz at the moment, but we are working on reducing this a further 5 to 10 dB. Enter your order number here.. Best Regards Martyn The Oscilloquartz 8607 is a few dB better than that at 1Hz offset. Bruce ___ 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.
Re: [time-nuts] Cesium Oscialltors and Low Phase Noise Frequency Standard
It sounds like a really nice oscillator. I'm sure that everyone would love to hear about the challenges and tradeoffs in designing such a high performance quartz oscillator. Do you guys cut your own crystals? How much of the improvement comes from a better SC-cut crystal and how much from better electronics or better ovens? I could go on and on, you wouldn't want to sit next to me on a plane. jeff Martyn Smith wrote: Hi, Is there anyone out there clever enough to design me a cesium frequency standard?? There's only two manufacturers that I know of and there's room for another supplier. Also you may be interested to read we have just developed what we believe to be the worlds lowest close-in phase noise 10 MHz oscillator. It makes -121 dBc/Hz @ 1 Hz. Noise floor is only -162 dBc/Hz at the moment, but we are working on reducing this a further 5 to 10 dB. Enter your order number here.. Best Regards Martyn This Email is from: Martyn Smith Precision Test Systems LTD Tel: +44 (0) 1245 329608 Email: [EMAIL PROTECTED] Web: www.ptsyst.com ___ 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.
