MFJ-1789 Rotatable Mini-Dipole
Instruction Manual
4
6m
300
750
600 KHZ
2m
200
300
4.0 MHZ
Mechanical Specifications
Mast Size:
1- to 1-1/2” diameter
Overall Length:
17 feet
Turning Radius:
8.5 feet
Weight:
17 pounds
Wind Load:
2 square feet
CHOOSING A LOCATION FOR THE ANTENNA
For best performance on receiving and transmitting, mount the antenna in a clear location above or away
from buildings, towers, feedlines, utility wires, and other antennas. While your own ingenuity and
particular circumstances will determine the final mounting method, we'll pass along a few ideas for both
permanent installation and portable operation.
•
Never
mount this antenna in a location that will permit unsuspecting people to come in contact with
the loading spokes or any other part of the antenna.
•
Never
mount this antenna where a mechanical failure might allow the antenna to contact power lines
or other utility wires.
•
Always
ground the feedline at the point where it enters a building to a good earth ground for
lightning protection.
WARNING: Always mount this antenna so that it is out of the reach of adults and children.
The capacitance elements can cause injury and/or severe RF burns.
Permanent Installation
The ideal installation is a rigid pole or roof mount that puts the antenna completely in the clear. If the
ideal installation is not possible, choose the best compromise. TV mast, heavy-duty rigid electrical
conduit, and steel water pipes are suitable mast materials. This antenna will mount on masts between 1
and 1-1/2" OD. The use of soft or thin wall masts is not recommended
Portable Operation
The MFJ-1789 may be disassembled as necessary for transporting to a temporary location. Ideally, just
remove the two HF loading coil assemblies leaving the two main elements and 2- & 6-meter stub
assemblies intact.
Some retuning may be required after moving the antenna.
Even for temporary or portable operation, do not be casual about selecting a suitable mast. If the antenna
falls, it will be damaged and may cause serious injury. Whatever type of installation you choose,
remember that the antenna should be installed where it can
never
be contacted by people or animals or
come in contact with power lines.
