MFJ MFJ-1924 User Manual

TM

Model MFJ-1924

INSTRUCTION MANUAL

CAUTION: Read All Instructions Before Operat ing Equipment !

MFJ ENTERPRISES, INC.

300 Industrial Park Road

Starkville, MS 39759 USA

Tel: [phone] Fax: [phone]

VERSION 0B

COPYRIGHT 2006 MFJ ENTERPRISES, INC.

MFJ-1924 Screwdriver Controller with Memory Instruction Manual

Contents

Introduction............................................................................................................ 1

Features ................................................................................................................. 1

Front Panel............................................................................................................. 1

Installation ............................................................................................................. 2

Motor Operating Voltage....................................................................................... 3

Menu…. ................................................................................................................. 3

Technical Assistance.............................................................................................. 5

Storing Memory..................................................................................................... 5

Schematic............................................................................................................... 6

 2006 MFJ Enterprises, Inc. ii

MFJ-1924 Screwdriver Controller with Memory Instruction Manual

Introduction

The MFJ-1924 Screwdriver Controller provides manual operation for tuning
screwdriver antennas. In addition, tuned positions can be saved in one of the 10
presets so it can be recalled later. A 4-digit counter is used to display the current
antenna position. A sensor is required for the counter and automatic operation
to function properly. This controller is compatible with single and dual sensor
setups. If your antenna does not have a sensor installed, contact the antenna
manufacturer or MFJ.

Features

• 4-Digit Turns Display

• 10 Programmable Presets

• Manual Up/Down Buttons

• Current Sensor Trip for Antenna/Motor Protection

• Auto-Park: Lowers antenna to lowest position and zeros counter

• Powered From 12V Vehicle Supply

Front Panel

• Power: Push button switch powers the controller on and off.

• Up: Moves the screwdriver antenna up.

• Down: Moves the screwdriver antenna down.

• Buttons 1 – 5: Top bank of preset buttons.

• Buttons 6 – 10: Bottom bank of preset buttons.

 2006 MFJ Enterprises, Inc. 1

MFJ-1924 Screwdriver Controller with Memory Instruction Manual

Installation

There are six wires that need to be connected in order for the controller to
function properly.

1. The red wire needs to be fused and connected to the vehicle’s +12

2. The black wire needs to be connected to the vehicle (station) ground.

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.

If the supplied red and black wires are not long enough, Use 16 AWG
wire to add additional length.

WARNING: Do not reverse the polarity of the Red and Black

wires. Damage will occur to the controller.

3. The remaining four wires are connected to the antenna. The Green and
Yellow wires are connected to the motor. The polarity of the motor
connection determines the direction of the antenna. If the motor moves
in the wrong direction, swap the wires or see the menu setup section for
setting the correct direction.

4. The Brown and White wires are the sensor wires and should be
connected to the magnetic sensor on the antenna. There is no polarity
associated with these wires. The following table shows the wire color
and connections.

Red +12VDC
Black Vehicle Ground
Green Antenna Motor
Yellow Antenna Motor
Brown Magnetic Sensor
White Magnetic Sensor

You will need to connect wires to each of these four wires, so that they will
reach your screwdriver antenna. Use quality insulated wire for these extensions.
The motor control wires should be no smaller than 18 AWG. the sensor wires
should be no smaller than 24 AWG. Take care and follow your antenna
manufacturer’s suggestions about routing these wires for a mobile installation.
Avoid routing control wires with the feed line. Make sure a RF choke is placed
around the control lines at the antenna.

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.

 2006 MFJ Enterprises, Inc. 2