[time-nuts] Comparing PPS from 2 GPS units
Hal Murray
hmurray at megapathdsl.net
Thu Dec 13 09:57:34 UTC 2012
Suppose I want to compare the PPS outputs of 2 GPS units. The problem is
that I don't know which one will happen first.
If I feed them into the start/stop inputs of a typical timer/freq box, I
don't know which is which. If I get them wrong, the answer will be
0.999999xx seconds rather than the -0.000000xx that I want.
Is there a simple solution for this?
My straw man is to use the antenna cable delay setting to offset one of the
PPS pulses a long way.
Plan B would be a physical delay unit. But they are probably temperature
sensitive, and I'm not setup to keep anything at a constant temperature.
Do any of the counter/timer boxes have a mode for this? If so, is there a
buzzword I've overlooked?
--
These are my opinions. I hate spam.
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