This board will make a GPS Disciplined referenced oscillator using an Arduino Nano controller and a NEO-7M GPS receiver and generates a 50ohm output signal. These oscillators use the GPS timing signal to lock the output frequency to a very high accuracy, easily within a few hertz. Ideal for calibrating oscillators, counters or your radio.

The keypad allows you to check how many satellites are being received, that the oscillator is locked and to enter the output frequency required. It will work up to 12MHz.

Not my design, so all credit goes to Louis Scully and, in my view, this project should be better known. So selling on the spare boards at cost. See more at http://www.scullcom.uk/category/projects/frequency-reference/

Simple and easy to get running. The second photo shows my own unit complete and generating a 6MHz signal.

(Note that this is just the bare board, no components included.)