[time-nuts] getting accurate timing on RTL-SDR output

[Mark Sims]

Note that on a lot of GPS devices that only one edge of the 1PPS pulse is stable and the other edge can jitter a bit.

Also, you might want to try programming the PPS to a 50% duty cycle (but having an asymmetrical PPS pulse might have some advantages for post processing).

The receiver with the best 1PPS stability  that I have tested is the Furuno GT-8736.  Its typical span is under +/- 4ns from nominal.