But doesn't it matter what your definition of "short term" really is?
I have some Wenzel OCXOs that hit 5E-13 for a 1 second tau. No Rb or Cs or Z3801 that I have running get that good at 1 sec tau! Over 10,000 is a different matter, however. -Brian, WA1ZMS -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Tom Duckworth Sent: Wednesday, April 23, 2008 6:13 PM To: 'Discussion of precise time and frequency measurement' Subject: Re: [time-nuts] Disciplining Rubidium Antonio, Absolutely! With a good XTAL you have parts in the 9th, short term. With a XTAL controlled by a Rubidium, in the phase-lock feedback loop, you have parts in the 12th, short term. With the Rubidium disciplined by the GPS, with its on-board Rubidium/Cesium oscillators updated from the ground every orbit, you have parts in the 14th, short term. In other words, your XTAL/Rubidium/GPS has an effective short-term Allen variance equivalent to a good Cesium; and better than a single Cesium, long term, for a lot less money! Tom Tom Duckworth 510-886-1396 -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED] Sent: Wednesday, April 23, 2008 3:11 PM To: time-nuts Subject: [time-nuts] Disciplining Rubidium Does it make any sense "GPS disciplining" a rubidium oscillator? In such a case we have a chain made of GPS - Rubidium - XTAL as opposed to the simpler case of GPS - XTAL (assume that XTALs are of the same quality, and so the control loops). Does the addition of Rb in the middle of the chain add any real advantages? Antonio I8IOV _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
