The BDC assembly is used as a test device on Satellite Access Point (SAP) antennas located worldwide.  The BDC assembly down converts a Ka band signal, 17.7 GHz to 19.7 GHz, from the LNAs on either polarization of the antenna to between 950 and 2150 MHz using a high and low band block downconverter.  The user has the ability to select a signal from either LNA and either BDC.  The BDC assembly can allow the user to communicate via Ethernet optical interface to the Antenna Control Unit (ACU).  The BDC assembly also includes an NTP server with GPS antenna that can communicate with the Antenna Control Unit.