[eagle] Re: Eagle 10 MHz Clock

Tom Clark, K3IO K3IO at verizon.net
Mon Apr 9 20:52:15 PDT 2007


Bill Ress wrote:
> 1) What is the reason for requiring all LO's to be locked to a 10 MHz 
> satellite system clock or are they?
>
>   
That requirement comes from me. It is my fervent hope that we will be
able to use the transponders for accurate coherent s/c ranging;
therefore we want the TX and RX LOs to be related to a common (high
stability) reference. There are also some (undocumented) desires (that
may re$ult in $ome project $upport) to use the microwave transponders
for high accuracy, intercontinental time & frequency synchronization.
> 2) Have the performance specifications for the 10 MHz clock been 
> developed and what are they (in particular phase noise, frequency 
> stability, susceptibility to digital hash, and power level available to 
> each using subsystem - to name a few)?
>
>   
My desire, if it can be promoted (from unnamed $ource$), to use what is
often called an Ultra-Stable Oscillator (USO) of the type carried on a
number of interplanetary s/c. I envision us being able to tweak the
frequency slightly under ground command (i.e. a D/A converter built into
the USO).
> My apologies for sending to the entire Eagle list but I'm not sure who 
> has the responsibility for the clock.
>
>   
System level responsibilities are up for grabs AFAIK. So far, my
contribution has been to say "It would tremendously augment capabilities
if ...".

Please keep asking these questions!    73, Tom



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