On Sat, May 10, 2014 at 4:00 AM, Iain Young <iain@g7iii.net> wrote: > you may want to build from > source to ensure all ref clocks are enabled > Yes, you have to buid NTPD if you want PPS. This effects ATOM, NMEA and a couple other refclocks. It can also be unpleasant beause you have to track down timepps.h. I've opened a bug at ntp.org about timepps.h but I don't expect it to be fixed. Likewise the Thunderbolt patch I sent them (to make note something that might be of interest to time-nuts).