Hi Bert, > I have a FTS 1200 that is off by about 2 Hz. Have decided to take a > closer look. Does any one have technical Information I should study > before I > open it up. > Thanks > Bert Kehren The efc range on my FTS 1200 goes from about -1.5Hz to +2Hz (0V to +10V). Is your FTS1200 of even with max (or min) efc voltage? -- Björn