[time-nuts] Need 10 MHz for DSN space-probe hunting

jimlux jimlux at earthlink.net
Tue Sep 13 15:49:10 EDT 2016

On 9/13/16 10:04 AM, Mike Baker wrote:
> Hello, Time-Nutters--
> Full disclosure--  I am a complete newbie at understanding the
> intricacies of generating a really stable, low phase noise, accurate
> frequency reference for microwave reception up around the 8 GHz
> DSN (Deep Space Network) band.  I have been following the back
> and forth comments on the Time-Nuts list about improving the
> Trimble T-bolt's 10 MHz output but confess that most of it is pretty
> much deeper technical voo-doo than I am comfortable with.
> I have been following the exploits of a group of folks around the
> world who receive the incredibly weak signals from space probes
> such as Juno.  The idea is to detect the signals and then deduce
> and confirm what probe is being detected by analyzing its doppler
> and orbital characteristics.

> Accordingly, what possible options might I have open to obtaining
> a decent 10 MHz frequency reference for working up at the 8 GHz
> DSN band?   Any feedback on this will be much appreciated!

I think that any sort of OCXO will do... your tbolt is probably "quiet 

It's phase noise in the 1-100 Hz kind of area that you want to think 
about,  your LO multiply chain will increase the noise floor by 
20*log10(N) going from 10 to 8450.  (about 60dB)

The carrier you're looking for is very narrow band.. you can look at the 
data sheet for a SDST (on General Dynamics website) and get the phase 
noise of the AuxOsc, which will be the worst case noise.  If they're 
doing 2 way turnaround, the noise is better.

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