In a message dated 2/22/2007 22:17:43 W. Europe Standard Time, die@dieconsulting.com writes: Mine is off more (or was until it died a couple of weeks ago). But I have yet to attempt the full cal procedure for reasons similar to yours. I did find that using GPSDO 10 mhz the error was quite stable (always reading low in my case, not high) but apparently just barely within the spec in the manual. Here is an interesting factoid: the wavecrest DTS-207x series also has a problem displaying frequency with high resolution. They only display down to 10Hz digits or so if I remember correctly, but for A/B delays Pulse Width etc they show femtoseconds... bye, Said <BR><BR><BR>**************************************<BR> AOL now offers free email to everyone. Find out more about what's free from AOL at http://www.aol.com.