[time-nuts] Radio Shack GPS Module

[Hal Murray]

tjv at westwood-tech.com said:
> I also already own several Trimble Resolution T's and something I've been
> wondering about for a while is whether there is any downside, difficulties
> or problems with mounting a bare GPS receiver board inside a computer case.
> If there are problems, would enclosing it in a shielded enclosure ameliorate
> those problems?  Has anyone on the list done this?

I don't have any solid data.

Computers are well known to be a source of EMI.  Many have gone to spread 
spectrum on the main clock.  That makes it (much?) cheaper to get past the 
FCC tests.  Whether or how much it actually helps or not depends on the 
frequencies, your particular modulation/encoding scheme, and such.

There are/were PCI cards that had the GPS receiver mounted on them so it 
should be possible.

That was a while ago.  I haven't seen that sort of card recently, but I 
haven't been looking.  Maybe as GPS receivers got more sensitive that doesn't 
work as well.  Maybe everybody just shifted to USB.

If I was doing it, I'd put the GPS stuff in an external box and connect it 
via RS-232.  That works if you are interested in microseconds.  If you want 
better than that, things get interesting.  I'd probably investigate a FPGA 
card.


-- 
These are my opinions.  I hate spam.