Poul, This is a good point and I hadn't thought of that. I'll make sure the pin header going over to the soekris board will still receive the 'dirty' PPS signal, and route the corrected signal only to the SMA connector on the board.
On Wed, Dec 3, 2014 at 1:49 AM, Poul-Henning Kamp <[email protected]> wrote: > -------- > In message <[email protected]>, Mike Cook > writes: > > >> I'm using a soekris net4501 that I hacked according to > >> http://www.febo.com/time-freq/ntp/soekris/ > > >> Recenlty I felt the need to add hardware sawtooth correction. > > For the net4501 that is probably a bad idea. > > When you do the sawtooth correction in software, the hw-component > acts as a jitter to smooth out the net4501's ~120nsec timestamping > window. > > Without this jitter, you will have the timestamps sit in the same > window for long periods of a time and then suddenly switch to to > the neighboring window rather rapidly. > > With the jitter the switch gets "smeared" out over a longer > period of time, which is a more sensible input to a PLL. > > -- > Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 > [email protected] | TCP/IP since RFC 956 > FreeBSD committer | BSD since 4.3-tahoe > Never attribute to malice what can adequately be explained by incompetence. > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
