[time-nuts] Austron GPS antennas
magnus at rubidium.dyndns.org
Thu Aug 18 22:32:04 UTC 2011
On 18/08/11 23:49, k4cle at aol.com wrote:
> Hi Magnus, thanks for that information. I had forgotten about that
> Plessey GP2010 and GP2015 RF chip. The only problem is that you have to
> do a divide by 7 on the 40 MHz signal that Plessey did in the GP2021
> correlator IC. Using an old SuperStar RX is a good reconmendation.
> Thanks. Doug, k4cle.
There is a whole little line of GPS receivers of the same chips.
Hacking in external clock onto a SuperStar isn't all that hard.
You will not have to do the divide by 7 in this case, For this
application you get 35,42 MHz out in the second filter stage, just tap
in on that with a diffrential pair after the filter and you are
essentially done. In the GP2010/2015 topology it goes back in for AGC
and sampler action. If your receiver expects the 35,42 MHz signal, it
gets inserted into that place from a receiver buffer with filter and
then the rest of the analog and digital path is continued... that's how
they use up two GP2010/2015 chips, but can get away with longer cable
runs since the damping of 35,42 MHz is much less than that of 1575,42
MHz in RG-58....
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