Kat said the following on 05/03/2009 12:05 AM: > Nero Imhard wrote: > > A much more reasonable approach would be to hook up the OCXO to > your > > computer's hardware clock for better stability. > Unfortunately not as easy as it seems high frequency clocks are > notoriously difficult to construct and calibrate and a new custom > clock or clocks would be needed every time I changed server so I opted > to do something portable.
I try to avoid shameless plugs, but have you considered the TAPR Clock-Block (http://www.tapr.org/kits_clock-block.html)? It's a clock synthesizer specifically designed to allow clocking a PC motherboard from an external OCXO (or other high quality) reference. It'll take inputs like 5 or 10 MHz and generate outputs up to a couple of hundred MHz. I use the Clock-Block to generate 33.333... MHz to drive a Soekris 4501 single board computer which has some unique hardware timing capabilities such that by adding a high quality PPS you end up with an NTP server that can keep time to fractions of a microsecond. I have details of that at http://www.febo.com/pages/soekris.* TAPR is currently out of stock on the Clock-Block, but we are having another run made and they should be available Real Soon Now. John * Note -- if you look at the performance plots linked from that page, things won't look so good right now -- the Cesium clock that I use as the reference for the offset comparisons died and is now acting like an OCXO. Haven't had a chance to reconfigure to switch to the alternate Cs source yet. _______________________________________________ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
