Bob -----Original Message----- From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On Behalf Of EWKehren@aol.com Sent: Thursday, January 12, 2012 10:43 AM To: time-nuts@febo.com Subject: Re: [time-nuts] FE-5680A Mechanical Question Bringing out the C field in my estimation does not effect long or short term.

If you take 2 samples out of a 1nS counter than you can estimate your measure with a 500pS resolution (5E-10) with an uncertainty (noise) of 7E-10.

v=SXNT4T56EmM Anybody want to estimate the adev? :) ----------- They have several coupled pendulum exhibits. Are coupled pendulums (or oscillators?) useful for timekeeping? They sure are weird face to face. The best one is out front as an art exhibit. It's a T with swivel arms on each end of the T.

What didn't show up in the record is the lat/lon estimate for Best's cell phone.

Another thing, the frequency detector phase history may need to be unwrapped prior to subtraction in order to make sure the frequency estimate becomes correct. > Turning on the "D" term in a PID with a prefilter is mostly not > recommended, They tend to just cancel each other.

Once dollars are mentioned, desired specifications usually are attained at fairly quickly :) We recently had an inquiry that we forwarded to a major atomic oscillator vendor, and the estimated $10 Million design cost and 10 year design time quickly shut that idea down..

TRAIM (just like any estimator) looks at the single input it has and says “that must be correct”. Give it two inputs and it can look at the solution for each and decide if they are close enough (your TRAIM threshold) to be correct.

An ADC after the mixer could be used to process the audio and estimate it’s frequency. The same sort of ADC setup might give you some phase noise data. The gotcha with all this is that a single mixer / quadrature approach will give you *much* better phase noise data than a single or dual mixer setup.

The Z3801A will do a least square estimate of frequency error and then translate that into an initial DAC setting assuming it knows the EFC sensitivity, and the loop will work out the rest from there (hopefully). Getting EFC in the right neighborhood is probably wise for this reason.

Enrico presented an approach to estimate the removed noise and simply add it back. Mike Driscoll discussed the potential of doing a different approach with mixers for higher amplitude level.