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[time-freq] Re: Using Reflock II on modulated oscillator

Doug Bade kd8b at thebades.net
Sun Jan 14 18:10:26 UTC 2007

Sorry I should correct that.... I need better than 15 hz.... at 150 
mhz so I guess that would be .1ppm......preferably .01ppm.....but my 
comcern is impact of modulation being applied to the crystal oscillator....

At 01:02 PM 1/14/2007, you wrote:
>Hello Group;
>         Newbie Doug here...I am looking for a solution and I hope 
> the Reflock II is one so here is my project need.....
>         I would like to discipline a crystal oscillator in a 
> transmitter which is using analog audio modulation. I am only 
> needing 1ppm accuracy ( analog simulcast of 1200 baud modem tones). 
> The Transmitter is a GE Mastr II, I have choices of FM or PM 
> modulation. As the tomes are symetrical I assume frequency 
> excursions would be more or less symetrical in any long frame 
> sampling and therefor irrelevant..?? I am concerned that the 
> sampling period would be too long for a short term stability 
> oscillator as in the Mastr II.. Normally this oscillator cannot 
> maintain much better than a few hz by itself over the short term...
>         Can the Reflock II sample fast enough to maintain 10ppm in 
> this type of implementation?? If so I wish to acquire 2 for testing 
> asap, but do not wish to spend funds if it is not within the scope 
> of the device... I am not able to find much information detailing 
> time integration capabilities of the Reflock II..
>         Thanks for any input and any comments of alternate options 
> would be useful..
>         The intent is VHF Simulcast overlay on a non simulcast but 
> varactor compensated transmitter... albeit Phase Modulated of True 
> FM.... depending on which is a better choice...
>         My sampling is probably going to need to be at the 
> fundamental.... in the 12 mhz region.....
>Doug Bade
>KD8B -ex KB8GVQ
>time-freq mailing list
>time-freq at lists.tapr.org

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