R1. ANTENNA CONNECTOR - This female connector permits connection of the transmission line cable male connector
R2. PUBLICADDRESS - An external 4 ohm
R3. EXTERNAL SPEAKER - The "EXT.SP."jack is used for remote monitoring. The external speaker should have a 4 ohm impedance and be rated at least 7
watts. When an external speaker is connected, the internal speaker is disabled.
R4. POWERCONNECTOR - This connector allows you to connect the power to the PRO 640XL
with the power connecting cable.