Photo 1a—The PCB is approximately 2.5² on a side. It contains mostly SMD devices. The DBM mixer is in the center, and the two VCOs are located on the left and right sides. The top part of the board is the divide-by-64 circuitry. The lower part contains the IF amplifiers. b—The modified demo board on the left is attached to the RF module in its RF tight enclosure. For the sake of clarity, I omitted the shielded cables normally located between the RF and LO BNC connectors on the RF module and the controller.