On Wed, 26 Apr 2006 20:03:33, "Joe R." <rigdonj at cfl.rr.com> wrote: You are the proud owner of an extremely stable 5, 1 MHz, and 100 kHZ frequency standard. The drift over 24 hours is less than 5x10e-11. Before atomic standards became "affordable", these beasties were the secondary standards used in the lab. CRC