[time-nuts] Sneaky Errors
holrum at hotmail.com
Thu Oct 20 23:39:04 EDT 2011
1 ppm at 10 MHz is 10 Hz. It's been quite a while since I tested it, but if I remember correctly, if the Tbolt OCXO is off that far the GPS won't lock and the failure will be rather obvious.
The typical Tbolt oscillator has a DAC gain of 3.5 Hz/V. 10 Hz would be 3V of DAC offset. Lady Heather can determine your actual oscillator gain constant using the oscillator autotune function (& A from the keyboard). From that you can calculate the DAC offset required to get you 10 Hz of shift. Put the unit into manual DAC control mode and set the DAC voltage to what is needed to shift the freq that much. See if it locks...
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