MFJ MFJ-1924, Instruction Manual, Page: 5 / 13

MFJ-1924 Screwdriver Controller with Memory Instruction Manual
Controllers that have the 4 pin Molex plug.
1. The red wire needs to be fused and connected to the vehicle’s +12
VDC supply. The size of the fuse depends upon the current requirement
of the antenna motor. Typically a 5 Amp slow-blow fuse will work.
Some installations may require additional wire. Use 16 AWG wire to
add additional length.
2. The black wire needs to be connected to the vehicle (station) ground.
If the supplied red and black wires are not long enough, Use 16 AWG
wire to add additional length.
3. Connect the 4 pin Molex to the antenna.
motor control
Antennas that do not have a 4 pin plug. The plug can be cut
off. Use the chart below for wire color and its function.
CONTROL CABLE
RED MOTOR WIRE
BLACK MOTOR WIRE
GREEN SENSOR
WHITE SENSOR
WARNING: An RF choke must be placed around the control lines at
the antenna. The Controller may be damaged if an RF
choke is not used.
Motor Operating Voltage
This control unit is designed to operate with a screwdriver antenna that operates
on 12 volts. Many antennas operate on only 3 or 4 volts, a Dropping Resistor
can be used inline with the motor wires to bring the voltage down. Consult your
antenna manual or manufacturer for the operating voltage.
©
2006 MFJ Enterprises, Inc. 3