[time-nuts] 10MHz LTE-Lite

SAIDJACK at aol.com SAIDJACK at aol.com
Thu Nov 20 23:17:17 UTC 2014


Paul,
 
if you set the serial switch on the LTE-Lite over to the NMEA side then the 
 uBlox application will give you all sorts of bar graphs for signal 
strengths,  position, time, etc as it decodes all the NMEA messages.
 
Alex,
 
the TSC5125A user manual contains a description of the theory in its  
Appendix B. Its probably available on the Microsemi website as I don't think its  
confidential.
 
Also, I think John's TimePod user manual probably has a description of it.  
Otherwise I remember Sam Stein (who is behind the TSC units) had some PTTI 
or  similar presentations discussing the technology, but I don't know where 
those  could be downloaded.
 
Bye,
Said
 
 
In a message dated 11/20/2014 14:34:32 Pacific Standard Time,  
alex at pcscons.com writes:



Hi Said,
do you have any information about how that  "TimePod 5330A works" any 
principal  description?
73
KJ6UHN
Alex

On 11/20/2014 2:08 PM, S. Jackson  via time-nuts wrote:
> Hello Mike,
>   
> attached  is a 10MHz DIP-14 TCXO Phase Noise plot from a random  LTE-Lite
>  unit.
>   
> I had sent out a 20MHz typical phase noise  plot some weeks ago, and
> comparing the two they are almost perfectly  6dB apart as would be 
expected from
> the 20log(n/m) relationship. There  are variations from unit to unit of
> course,  but it does not seem  like one version of the board or the other 
has
> advantages  in  terms of phase noise.
>   
> I had also sent out a  superimposed plot of the 20MHz and the divide-by-2
> 10MHz output of the  same board at that time, and again the relationship 
was
> almost  perfectly 6dB lower at 10MHz versus 20MHz.
>   
> While  phase noise follows theory, it does seem that the DIP14 metal 
shield
>  has a beneficial effect on the ADEV stability though. The plots we are
>  getting  are pretty darn good, and I want to test more boards before I  
post any
> ADEV,  because its quite a bit better than our  specification and I want 
to
> make sure  its  real.
>   
> The 10MHz DIP-14 boards do not have an  isolating buffer like the 20MHz
> boards do, on these the TCXO drives  the output directly, so one must be 
careful
>   to set the  equipment to 1M Ohms input impedance or use a buffer
> externally,   which is what we did to measure the attached PN plot.
>    
> Bye,
> Said
>    
>





More information about the Time-nuts_lists.febo.com mailing list