[time-nuts] SDR GPS

[Jim Lux]

On 11/24/11 9:33 AM, Collins, Graham wrote:
>
> Perhaps not in the same league or with the same gee-whiz appeal as a SDR GPS receiver but how about your own DIY GPS receiver:
>
> http://dangerousprototypes.com/2011/11/24/homemade-gps-receiver/
>
> and the authors web page:
>
> http://www.holmea.demon.co.uk/GPS/Main.htm
>

Yes, indeed.. that's sort of the other approach to building receivers, 
with a first mixer and filtering at IF.  These days, most people just 
amplify and filter at the L1,L2,L5 frequencies and sample the 1 bit 
output at an appropriate rate (38-39 MHz).  With Holme's approach, you 
need to synthesize the 1.5 GHz LO, which takes more gates, parts, etc.