I have installed the Efracom LPRO-101 into a used rack cabinet after removing the card cage. The cabinet had a power supply module outputting 32 vdc which will be reduced to 24 volts by a LM317 regulator to run the Rubidium. I decided to acquire a OCXO for providing the station 10-MHz Reference instead of using the Rubidium. I did this for two reasons: The Rubidium has a finite life and does not exhibit low phase noise. The OCXO was purchased from e-bay for $39.95. It feeds a Downeast Microwave 10-4 10-MHz 4-way distribution amplifier to feed equipment in the shack requiring an accurate reference frequency. A 12-volt sealed-acid battery is float charged to 14 volts to ensure the OCXO will run continuously even in event of a ac power outage. The OCXO can be periodically adjusted to match the Rubidium standard. The rubidium is mounted to a 1/4-inch aluminum plate with six counter-sunk 4-40 screws and the plate is attached to a 6-inch square heat sink with 2-inch deep fins (click image for larger view): Photo of a simple BITE lock indicator board made by Chuck, WA3IAC; Schematic diagram of the Rb and OCXO unit.