[time-nuts] Question about specifications for Quartzlock GPS antenna down-converter
magnus at rubidium.dyndns.org
Sun Mar 15 09:04:31 EDT 2009
bg at lysator.liu.se skrev:
> Hi Brooke and Russel,
> Meinberg does the same thing, but they send a 10MHz - nice choice!! - up
> the coax to receive an IF of 35.4MHz.
As I have commented before, I suspect that they use the Zarlink chipset,
since they have 10 MHz input and 35,4 MHz is an intermediary frequency
in that frequency scheme which is available for insert. Using one analog
front in the antenna and one analog front in the receiver and feeding
them with the same 10 MHz it all works out nicely.
I don't know what solution Quartzlock is using.
The reduced damping (and hence longer cable runs) is one benefit from
down-converting, another could be reduced phase shift problems, but I
think for L1 receivers this is not as major issue.
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