The photograph on the left shows the inside of the GPS Disciplined OCXO. Most of the box is taken up with the mains PSU! The interface PCB on the left is based upon James Miller’s design and includes the additional amplifier required to drive the Isotemp 10MHz OCXO on the right. The Jupiter GPS board is behind the 10MHz oscillator, to the right of the interface PCB. I also made a small ‘daughter board’, clearly visible in the centre, which mates with the 20-pin header on the Jupiter board.