> > (btw is there such a thing as a desktop rubidium atomic clock with 1 PPS?) Stanford Research prs10 (List $1495) is a building block FS725 is a fancier version in a box with power supply, 1pps in and out, 5 and 10 MHz etc, RS232 interface, etc. List about $2500. http://www.thinksrs.com/products/FS725.htm