G'day, I am trying to get a Symmetricon UCMM 089-03861-02 board up and running, I purchased it off Aliexpress sans OCXO. I found a site saying the Oscilloquartz 8666A was a suitable replacement. I Found an 8666A on fleabay and installed it. See the screenshot from Lady Heather, it shows the dac voltage varying wildly, where looking on the control pin on the OCXO with a cro it is stable at 5.33V. Also on the osc under receiver data shows a high number compared to another Trimble UCCM unit I have here. But as you can see comparing the Symmetricon and Trimble units on my 53132A counter I am getting sub mhz accuracy. The OCXO may have to be re-aged. Has anyone other thoughts on the hight osc value? Cheers Rob Leahy