INTRODUCTION: The MFJ-1754 is designed for use on the 2 meter and the 70 centimeter bands. On the 2 meter band the MFJ-1754

behaves as a vertical 1/4 wave antenna, however on 70 centimeter band the MFJ-1754 is a gain antenna. It is

constructed of a 1/2 wave over a 1/4 wave antennas, which gives it a higher gain for extra long range. The MFJ-1754

uses a sloped ground plane to ensure a low SWR across both bands and, to minimize the feed line radiation which

can result in pattern distortion and skewing.

CHOOSING A LOCATION FOR THE ANTENNA

The MFJ-1754 can be mounted on any 1" to 1 1/2" mast (conductive or non conductive.)

The best performance on receiving and transmitting will be obtained by mounting the antenna as high as possible in a

clear location above or away from buildings, feed lines, utility wires, and other antennas. While your ingenuity and

particular circumstances will determine the final mounting method.

MFJ-1754 PARTS LIST

The MFJ-1754 is shipped partially assembled. The following parts should be in the package:

ITEM QUANTITY DESCRIPTION

A 3 Radials

B 1 Chassis

C 3 6-32 X 1/2 Screws, & nuts

D 1 U-Clamp Assembly

TOOLS REQUIRED

[ ] - 7/16" Open End Wrench

[ ] - #1 Screwdriver

[ ] - 5/64" Allen Wrench (Provided)

SAFETY PRECAUTIONS

WARNING !

- Always mount this antenna so that it is out of reach of adults as well as children. The radiator and the

ground plane can cause injury and or severe RF burns.

- Always wear eye protection when working with antenna

- You can be killed if the antenna, feed line, or the equipment used to install the antenna accidentally

contact any utility lines. Never install an antenna near power lines.

ASSEMBLY AND INSTALLATION PROCEDURE

MFJ-1754 Dual Band Antenna Instructions

2

During assembly of this antenna refer to the figures in this manual and the picture on page 1.

After the antenna is assembled it must be checked and adjusted for resonant frequency and SWR.

NOTE: Wear safety glasses whenever working near or on this antenna

STEP BY STEP PROCEDURE

1- Insert a 6-32 x 1/2" screws through hole #1 with thread toward the inside of the chassis. Start a 3/8" nut on the tip

of this screw (see Figure 1).

2- Install the remaining two 6-32 x 1/2" screws and 3/8" nuts into hole #2 and hole #3 as was done in step 1

3- Insert a radial into hole A, straight end first (see figure 2). Sandwich the hooked end of radial between the chassis

and the 3/8" nut of the screw in hole #1. Secure the radial by tightening the 6-32 screw .

4- Install the remaining radials in the same manner. One radial should be inserted through hole B and secured with

screw in hole #2, the other through hole C and secured with screw in hole #3.

5- Assemble the U-Clamp in the chassis as shown in figure 2.

6- The antenna assembly is completed now. Antenna can be tested for frequency and SWR using an analyzer or a

transceiver on low power, then fine tuned before mounting it on a permanent location.

TUNING THE ANTENNA

The antenna is pre-tuned for low SWR on both the 2 meter and the 440 MHz bands. However, the SWR can change

from location to an other. In this case some minor adjustment is perhaps necessary.

Adjustment on this antenna in done by losing the set screw (see figure 1) and increase or decrease the length of the

radiator element to lower or increase the frequency respectively.

If a high frequency is desired and can not be obtained at the minimum setting of radiator length. Approximately 1/4

inch off the radiator bottom end can be cut to increase the frequency resonance of the antenna.

If the SWR of the antenna can not be adjusted using the radiator, it is possible to slightly bend the radials (only a few

degrees) up or down, one at a time to achieve a minimum SWR.

MAINTENANCE

MFJ-1754 is constructed of heavy duty non corrosive materials (aluminum and stainless steel hardware) and should

withstand normal climates for many years. The use of some type of coaxial connector moister protections

recommended at the coax connection, especially in coastal areas where salty mist is common.

GE makes "SILICON DIELECTRIC COMPOUND" which are good material for this application.

Selected MFJ PRODUCTS Normally delivery 14-21 days special order,