Antenna, Radio: Description and Operation

When the radio is turned on, voltage is applied to the antenna relay coil. The antenna relay contacts close, and battery voltage is supplied to the antenna motor. The other motor terminal is grounded through the antenna motors up switch, and the antenna relay contacts. The motor drives the antenna up. At the end of its travel, the up switch opens and the motor stops.

When the radio or ignition switch is turned off, battery voltage is removed from the antenna relay coil. The contacts open to the position shown in the schematic, applying battery voltage to the WHT wire. The DK ORN wire is now grounded. Since the DN switch at the antenna is now making contact with the WHT wire, the voltage to the motor has reversed polarity. It runs in the opposite direction and drives the antenna down. At the end of its travel, the up switch opens the circuit. Both sets of switches are now in the positions shown in the schematic with the radio off and the antenna down.

The antenna is connected to the radio by RG-62 type coaxial cable.