[time-nuts] STEL Patent for 48 bit D/A based on NCO IC

[Brooke Clarke]

Hi:

While reverse engineering the Quantic (then Absolute Time, then ??) 
Q5200M Timing GPS receiver I came across a Stellar GPS patent that 
describes how this receiver controls it's 10 MHz output using a NCO IC 
as a 48 bit D/A converter.  But I have not been able to find a modern 
replacement for the IC.  Is there one?

I'm also looking for the downconverter antenna.

http://www.pacificsites.com/~brooke/Q5200.shtml
U.S. patent 5440313 
<http://patft.uspto.gov/netacgi/nph-Parser?patentnumber=5440313> 
(remember that SA was on at the time of this patent.)

Have Fun,

Brooke Clarke

w/Java http://www.PRC68.com
w/o Java http://www.pacificsites.com/~brooke/PRC68COM.shtml
http://www.precisionclock.com



Rob Kimberley wrote:

>Ulrich,
>
>I'm absolutely certain that this is how they did it. My old boss the late 
>Bob Ellis made a big point about this being a new way forward that didn't 
>involve any direct tuning of the Rb. You let it free run and correct using 
>the DDS technique mentioned. The rational was that this way you got on the 
>desired frequency quicker than the traditional PLL methods, which was a big 
>plus when installing these in Telco sites, as time was at a premium when 
>installing and testing the systems.
>
>Rob
>
>
>  
>