[time-nuts] cheap 5V OCXO in 14DIP has about 1E-9 drift per day

[Bruce Griffiths]

Bruce Griffiths wrote:
> Hal Murray wrote:
>> bruce.griffiths at xtra.co.nz said:
>>> The 16MHz is necessary for the loop to function: The mixer mixes 
>>> down the
>>> 26MHz to a pair of conjugate frequencies, 10MHz  and 16MHz. Thermal and
>>> device noise is sufficient to start the process.
>>> 10MHz = 26MHz - 16MHz
>>> 16MHz = 26MHz - 10MHz
>> What makes it stable at 10 and 16 MHz rather than 10.000001 and 
>> 15.999999?
>>
>> I'm assuming we are starting with a good 26 MHz crystal and that it 
>> would be hard to get filters that good.
>>
>>
> Asynchronous modes such as 10.000001MHz plus 15.999999 MHz can be 
> problematic if the loop delay is too high.
> http://www.femto-st.fr/~rubiola/pdf-articles/journal/1992im%28rubiola%29regenerative-divider-noise.pdf 
> <http://www.femto-st.fr/%7Erubiola/pdf-articles/journal/1992im%28rubiola%29regenerative-divider-noise.pdf> 
>
>
> http://ieeexplore.ieee.org/Xplore/login.jsp?url=http%3A%2F%2Fieeexplore.ieee.org%2Fiel5%2F26%2F23863%2F01093262.pdf%3Farnumber%3D1093262&authDecision=-203 
> <http://ieeexplore.ieee.org/Xplore/login.jsp?url=http%3A%2F%2Fieeexplore.ieee.org%2Fiel5%2F26%2F23863%2F01093262.pdf%3Farnumber%3D1093262&authDecision=-203> 
>
>
> http://tf.nist.gov/general/pdf/1800.pdf
>
> Bruce
Additional references that estimate the degree of tank mistuning 
permissable before asynchronous modes occur:

http://www.its.caltech.edu/~kaushiks/KS_RFIC.pdf 
<http://www.its.caltech.edu/%7Ekaushiks/KS_RFIC.pdf>

http://www.its.caltech.edu/~kaushiks/KS_TCAS.pdf 
<http://www.its.caltech.edu/%7Ekaushiks/KS_TCAS.pdf>

An early implementation:
http://www.dtic.mil/cgi-bin/GetTRDoc?Location=U2&doc=GetTRDoc.pdf&AD=ADA457231 
<http://www.dtic.mil/cgi-bin/GetTRDoc?Location=U2&doc=GetTRDoc.pdf&AD=ADA457231>

Bruce