MFJ MFJ-1765 User Manual

MFJ-1764, MFJ-1765, MFJ-1766

MFJ Dual Band (2 & 6 Meter) 5/8 Wave Super Gain Antenna

Instruction Manual

Thank you for purchasing the MFJ Dual Band 5/8 Wave Super-Gain Antenna. This antenna is
designed to operate both the 2-meter (144 to 148 Mhz) and the 6-meter (50 to 54 Mhz) bands.

Two versions of this antenna are available:

MFJ-1764: Single 5/8 wave Super-Gain antenna. This model is shipped partially assembled. The
following parts are supplied:

2 pieces Elements
1 piece Chassis assembly
1 piece Clamp assembly

MFJ-1766: Two 5/8 wave Super-Gain antennas. This model is shipped partially assembled. The
following parts are supplied:

4 pieces Elements
2 pieces Chassis assembly
3 pieces Clamp assembly
1 piece Direct feed splitter/cable harness

MFJ-1765: Direct feed splitter/cable harness assembly. This harness is shipped pre-assembled with
mounting bracket. A mounting clamp is also supplied. MFJ-1765 is used to feed two 5/8 wave
Super-Gain antennas. It can be purchased separately for those who have two MFJ-1764s and wish
to feed both MFJ-1764s together for additional gain.

Assembly Instructions

Refer to Figure 1 to assemble the 5/8 Wave Super-gain antenna.

1. Locate the ceramic insulators on the chassis assembly. A screw has been installed in each
insulator to hold it in place for shipping. Hold the insulator together, carefully remove the screw, note
the location of the nuts. These nuts will be used to install the elements.

Make sure that the flanged nut is screwed onto the element. Note that the flange part of the nut
MUST face toward the insulator. See Figure 1.

After removing the "holding" screw, insert the element into the insulator and through the lug on the
inside. Secure the element by screwing the other nut (taken from the "holding" screw (onto the end of
the element inside the chassis. See Figure 1.

Repeat steps 1, 2, and 3 to install the other element.

If you have purchased the MFJ-1766, you will have to assemble another Chassis assembly. Use the
same instruction as in step 1 thru 4.

Installation Instructions

MFJ-1274: Single 5/8 Wave Super-Gain Antenna

The Super-Gain antenna can be mounted on any 1" to 1-1/2" tubular mast. The mast my be a
conductive (metal) or a non-conductive material.

For optimum performance the antenna should be mounted as high as possible. However, if the mast
itself is located at a high elevation, such as a hill or mountain, the need for a tall mast will not be as
critical.

The antenna may be mounted horizontally or vertically. The antenna should be mounted horizontally
for SSB and mounted vertically for FM operation.

Once you have mounted the antenna, connect the feedline to the SO-239 on the antenna chassis
assembly.

MFJ-1766: Dual 5/8 wave Super-Gain antenna

If you are installing two 5/8 wave Super-Gain antennas, you may stack each Super-Gain antenna on
top of each other on the same mast. Each antenna must be separated by a distance of 12 feet
(antenna mount -to-antenna mount). See Figure 2. You may also install the two antennas horizontally.
Again separate them by 12 feet.

Install the cable harness (MFJ-1765) in between the two antennas. Connect one of the coax cables
with PL-259 to one antenna and the other cable to the other antenna.

Connect your antenna feedline to the SO-239 on the cable harness bracket.

Tuning Instruction