The BIC-500 allows the antenna automatic commutation from a damaged Main Transmitter (TX1) to a reserve Transmitter (TX2).
The unit has two connectors (ENABLE1 and ENABLE2) on the rear panel, to remote control the turning-on of TX1 and TX2.
The unit must operate with the Switch on the left of the front panel on NORMAL OPERATION.
This condition imposes the following interconnections:
Main Transmitter (TX1) interconnects to Antenna (ANT), Reserve Transmitter (TX2) interconnects to Dummy load (LOAD), ENABLE1 is a close circuit and ENABLE2 is an open circuit.
The BIC-500 switches the following interconnections if the Main Transmitter is damaged:
Main transmitter (TX1) interconnects to dummy load (LOAD), Reserve Transmitter (TX2) interconnects to Antenna (ANT), ENABLE1 is an open circuit and ENABLE2 is a close circuit.

TEST/RESET OPERATION
When TEST/RESET is selected by the Switch, ENABLE1 and ENABLE2 become close circuits (TEST operation).
Turning on the switch in NORMAL OPERATION, the unit will switch the Antenna to itself (RESET operation) only if the Main Transmitter TX1 operates with full power.

THRESHOLD ADJUSTING
The trimer on the left of the front panel is to adjusts the RF working threshold of TX1.
If the output power of TX1 decreases below this threshold, the unit switches the Antenna to TX2.