Yesterday I thought I'd try to do a bit of research regarding the
GPS modules used by kit owners.
Now I'm not sure if I've got all the model numbers correct but
from what I've seen so far, all the modules have a very narrow
1pps width output.
For example I've seen figures of nanoseconds and microseconds quoted on
the troublesome modules, yet my Reyax UP501 which works flawlessly has a whole 100ms width for the 1pps output.
From where I am standing it does seem that this pulse width is the
key to it all.
I remember some month ago some work by KA7OEI regarding using and RC
network across the 1pps outputs might help broaden the pulses to work.
Maybe a trawl through this groups archive might reveal some more ?
Just thinking aloud...
73 de Andy G0FTD (Reyax UP501 GPS user with zero hassles)
