[time-nuts] Long Wave Radio-Frequency standard testing

Gilles Clement clemgill at gmail.com
Sat Jan 16 10:24:55 UTC 2021


Hi Paul,
> I guess I would ask what the goal of the effort might be.
> It seems like a good answer. One thing I was amazed buy was that back in
> the 1960s HP wrote some papers on using WWVB. What they did was check the
> offset at distance everyday about the same time. This offered quite a bit
> more accuracy and avoided all of the night propagation effects. Essentially
> from day to day the path is about the same.
Interesting, do you know where I could find such papers ? 
> If your system is stable enough could you simply put it in holdover at
> night?
I don’t think so. It is quite sensitive and when uncoupled the VCO drifts significantly.
> The other question I had is how do you then use the locked crystal
> oscillator at 5.184 Mhz?
> Does it somehow divide down to a useful number?

5184000 =2e9 × 3e4 × 5e3 which leads to 200 possible divisors 
Among which : 1000 ; 2000 ; 4000 ; 6000 ; 8000 ; 9000 ; 162k ; 192k ….
I am using the PPS to lock other oscillators
One could use another OCXO frequency (typical 10MHz) and phase lock 
on an intermediate common divisor such as 2000Hz or 4000Hz etc...
I am currently looking at this option but it is more
complex and not sure it would provide better performances.   
> Nice project and good luck. Looking forward to hearing more.
> Regards
> Paul
> WB8TSL

Thank you, 
Best, 
Gilles. 




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