This really more about frequency than time but I thought it might be of interest. The Agilent 8920 series of instruments have an A15 module, the reference, which takes an external 10 MHz input and locks an internal TCXO to it then producing 1 GHz, 500 MHz, 20 MHz, 10 MHz, 1 MHz or 200 KHz outputs. I have an 08920-61191 which seems to be identical to the 08920-60319. They are available on eBay sometimes for around $40 to $50. I plan on locking the 8920 here at work to my Z3801, an OCXO or TCXO I want to compare to the ref in of the module, and counting the 1 GHz output with the 8920. This will multiply the error between the two 10 MHz sources by 100 making drift easier to see. Probably not the best way to do it, but quick and easy. Documentation is available on the Agilent website. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.