[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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