Antenna: Description and Operation
When the Radio control is in the "ON" position, voltage is applied from the Radio (CKT 143) to the Power Antenna Relay Coil. The relay contacts close, and battery voltage is applied through CKT 145 to the Power Antenna Motor. The "B" Motor terminal is grounded through the UP Switch, CKT 161 and the relay contacts. The Motor drives the Antenna Mast up. When the Antenna is at its full height, the UP Switch opens and the Motor stops.When the Radio or Ignition Switch is in the "OFF" position, voltage is removed from the Power Antenna Relay Coil. The Power Antenna Relay contacts open, applying battery voltage to the Motor through CKT 160. The Motor ground is now CKT 145. Since the DOWN Switch at the Antenna is now making contact to CKT 160, the voltage to the motor has reversed polarity. It runs in the opposite direction, retracting the Antenna Mast.
At the end of the Antenna's travel, the DOWN Switch opens and breaks the current flow. Both sets of switches are now in the places shown in the schematic, the Radio is "OFF" and the Antenna Mast is down.
The Antenna is connected to the Radio by coaxial cable.