[time-nuts] NCOCXO anyone?

Alex Pummer alex at pcscons.com
Fri Jul 29 13:31:34 EDT 2016

it is a way to use a carrier fc to make one SSB  signal with fm 
modulation frequency, use just the side-band, , which have a frequency 
of fc + fm = fR,  [fR/fc is a function of the SSB modulator carrier 
suppression capability,]  fm could be from less than 1/2 fc any 
frequency to zero, if it is zero fR =f c. With fm is not zero, the phase 
of fR will advance relative to  fc as long as fm is not zero if fm 
becomes zero the advance will stop.
The generation of a very small frequency offset will need fm = the 
offset frequency
To "clean up" the resulting fR, a PLL could be locked to it, which could 
look to one single frequency only [with very narrow tuning range 
oscillator, perhaps a a tunable crystal and very narrow loop filter 
[just to let pass fm ]
since oscillators are by definition amplifiers with infinite high gain 
that PLL could look  into fc!
Attila I don't know anything about any patent, but I developed that kind 
of system for video colour performance analyzing system in the "past 

On 7/29/2016 9:23 AM, Attila Kinali wrote:
> On Fri, 29 Jul 2016 00:26:07 +0000 (UTC)
> Bruce Griffiths <bruce.griffiths at xtra.co.nz> wrote:
>> Diophantine Frequency Synthesizer Design for Timekeeping Systems
> I quickly went over the papers people have pointed me at. Without
> having gone through all the math, the idea for choosing the PLL values
> looks neat. The 2-cascaded synthesizer is also the one used by Spectratime
> for their FemtoStepper, which bring us back to the question: How do they
> achieve phase steps? I see how offset frequencies are generated (with
> arbitrary small step sized), but I do not see how this can be turned
> in fine resulution phase steps when using PLL's as the controlling elements.
>> Discusses a diophantine synthesiser.Note Sotiriadis' work on diophantine
>> numbers and frequency synthesis appears to be a rehash of an old Patent
>> perhaps due to a lack of competent searching for prior art.This issue was
>> discussed on the list some time ago,
> Which patent are you refering to?
> 			Attila Kinali

More information about the time-nuts mailing list