[time-nuts] PPS pulse length (was: 1PPS for the beginner)

[Tom Van Baak]

> Arecibo did a kind of cute trick with their distributed 1PPS.   The one
> second pulses were of one length
> (100 ns as I recall), but the 10 sec boundaries had the pulses be about
> twice that length.  One could carry
> this scheme to considerable lengths as desired.

Dana,

One version of this would be to make the pulse width 100 ns * (1+STOD), where STOD (Seconds-Time-Of-Day) varies from 00000 to 86399. So your pulse width would vary from 100 ns to 8640000 ns = 8.64 ms. If 100 ns is too short use a range of, say, 1 us to 86400 us (86.4 ms). Maybe there's a reason no one has implemented this but I always thought it would be a cool self-clocking, self-identifying, IRIG-like format. And trivial to implement both the sender and receiver with a microcontroller

/tvb