Heh, when getting a GPS Disciplined Oscillator set up I was feeding the 10 MHz oscillator into an SDR to use as a reference clock and was calibrating against a

Heh, when getting a GPS Disciplined Oscillator set up I was feeding the 10 MHz oscillator into an SDR to use as a reference clock and was calibrating against a local cell tower. 7 Hz beat/offset at 1700 MHz!