[time-nuts] More Allan deviation data

Didier Juges didier at cox.net
Sun Oct 29 18:32:45 EST 2006


Dr Bruce Griffiths wrote:
> Didier
>
> Unless you have a particularly poor 10811 it is likely that the measured 
> Allan deviation is limited by the instability of your GPS receiver 
> PPS output.
> With a good GPS timing receiver setup you should expect an Allan 
> variance perhaps 5x lower than this as illustrated in Ulrich's article 
> for the AMSAT journal.
>
> Bruce
>
>   
Thank you Bruce, that is the kind of information I was looking for. The 
Jupiter will have to do for now, I have two of the same model. I may try 
a better antenna though.
I got a link to the gpskit.nl web page, with a lot of information on the 
Jupiter, through an off-list message, and I will experiment with the 
settings in the receiver (mask angle primarily)

It seems all I have left to do is find the best way to close the loop 
(!) and try again against another 10811. I also still have a lot of 
experimentation to do over temperature, and check the stability of my 
distribution amplifier.

I have learned a lot in the last few days, thanks to everyone on 
time-nuts who took the time to explain the details to me.

I have a lot left to learn and experiment with, but at least I am aiming 
in the right direction :-)

Didier KO4BB





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