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Subject: Re: Differences between GPS and WWV time
From: Rodney Myrvaagnes (rodneym@XXX.XXX)
Date: Fri Jun 22 2001 - 15:48:52 EDT
On Fri, 22 Jun 2001 15:25:58 -0400, Smith_Peter@XXX.XXX
wrote:
>However, as Dan Allen noted, receivers' internal clocks often drift,
>and shouldn't be trusted until the unit is tracking.
>
Yes, but even if it is tracking, as Dan (I think) also
noted, the display may not be updated fast enough. THis is
more likely to be a problem with handheld devices, where
battery life is a real consideration. Slowly clocked
microprocessors use less power. If the unit is handling a
bunch of other tasks, the screen update may wait.
My old Traxar (1988) did not have this problem, but it ran
through 6 AAs in 7 hours, and had a very simple display.
It is annoying that one can't trust the display, even
though you know that inside it knows the time to a tiny
fraction of a second.
Has anyone tested the fixed-mount versions of popular GPS
families to see if they are better in this regard? I
suspect the answer will be no, but they could take
advantage of the ample power available from the boat or car
battery.
Rodney Myrvaagnes J36 Gjoa rodneym@XXX.XXX
Senior Editor Electronic Products
"Fireman saves pregnant squirrel" -- Arizona Republic, Dec. 14, 2000
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