MFJ-2990 43-Foot Vertical Antenna Instructions revJ
MFJ-2990 43-Foot Self-Supporting Vertical Antenna
INTRODUCTION
The MFJ-2990 is a 43-foot self-supporting vertical antenna that covers 160-6 meters with the use of
a wide range antenna tuner. The MFJ-2990 has the lowest wind-loading and has the least visual
impact of any 43-foot vertical antenna on the market.
The MFJ-2990 is built-to-last – using incredibly strong 6063 T-6 aircraft strength aluminum tubing for
the radiator and all stainless steel hose clamps and hardware. And it assembles in about an hour.
WARNING: Improper installation and assembly can be hazardous! Read these instructions
thoroughly before attempting to assemble, install or operate this product! High power
transmitting devices produce voltages that can cause severe burns or other injuries.
SPECIFICATIONS
Electrical Specifications
Band Coverage: 160-6 Meters with external antenna tuner
Power Rating: 1500 watts CW/SSB
Mechanical Specifications
Antenna Diameter 2”OD bottom section
Overall Length: 43 feet
Weight: 20 pounds
Wind Load: 2 square feet
CHOOSING A LOCATION FOR THE ANTENNA
For best performance, mount the antenna in a clear location away from buildings, towers,
feedlines, utility wires, and other antennas.
• Never mount this antenna in a location that will permit unsuspecting people to come in
contact with any 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 to a good earth ground at the point where it enters a building for
lightning protection.
WARNING: Contact with the antenna during operation can result in severe RF burns.
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MFJ-2990 43-Foot Vertical Antenna Instructions revJ
Permanent Installation
The ideal installation location is a rigid pole set in concrete.
Portable Operation
The MFJ-2990 may be disassembled as necessary for transporting to a temporary location. Even
for temporary or portable operation, do not be casual about mounting integrity. 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 cannot be contacted by people or animals
or come in contact with power lines.
MFJ-2990 PARTS LIST
As you unpack your antenna, verify that the following parts are supplied:
Item Part Description QTY Part No.
1 2” OD x 0.12” x 6’ AL Slotted Tube 1 810-2000I-6S
2 1.75”ODx0.058”x6’ AL Slotted Tube 1 810-1750G-6S
3 1.625”ODx0.058”x6’ AL Slotted Tube 1 810-1625E-6S
4 1.50”ODx0.058”x6’ AL Slotted Tube 1 810-1500E-6S
5 1.375”ODx0.058”x6’ AL Slotted Tube 1 810-1375E-6S
6 1.25”ODx0.058”x6’ AL Slotted Tube 1 810-1250E-6S
7 1.125”ODx0.058”x6’ AL Slotted Tube 1 810-1125E-6S
8 1.00”ODx0.058”x6’ AL Tube 1 810-1000E-6H
Parts Pack
10 Stainless Steel Clamp 2-1/4 6 745-3128S
11 Stainless Steel Clamp 1-1/2 6 745-3116S
12 Stainless Steel Clamp 1-1/6 2 745-3110S
13 1” Tube cap 1 765-1000
15 Hy-gain Base Mount Assembly Kit 1 ATB-65
Mast saddle 2 758-9198
Insulator ABS 2 475500
U-bolt 4 5136900
Split washer 8 564792
5/16 Nut 8 555747
Base Plate 1 172734
4-40X3/8 Screw 2
4-40 kep nut 2
16 Legal Limit 4:1 Balun 1 80-AV6160-1
Optional Items:
MFJ-915 RF Isolator
MFJ-272 Lightning Surge Protector
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MFJ-2990 43-Foot Vertical Antenna Instructions revJ
TOOLS AND TIME REQUIRED FOR ASSEMBLY
The estimated assembly time is about one hour. Antenna assembly requires the following hand
tools:
• ½” wrench, #2 Phillips screwdriver
• 5/16" nut driver for hose clamps.
• Safety glasses.
• Felt-tip permanent marker
• 4-6 foot step ladder
Additional Materials Needed
1) Mounting pipe: 4-foot long steel pipe 2.0″ OD/0.125″ wall thickness.
2) Quick-setting concrete – For installing the mounting pipe
3) High quality low-loss 50-Ohm coax terminated with PL-259 connectors from antenna to
transmitter. LMR-400 coax cable is recommended.
4) 3/8” lugs for attaching radials to the ATB-65 mounting plate.
5) 18-gauge or larger copper wire for radials, insulated or uninsulated.
SAFETY PRECAUTIONS:
WARNING! You can be killed if the antenna, feedline, or the equipment used to install the
antenna accidentally contacts any utility lines. Never install an antenna near power lines!
1. Be careful when carrying and installing the antenna. It is heavy enough to cause you to lose
your balance if it is handled too casually or if the antenna is snagged on anything.
2. Mount the antenna to minimize accessibility. The antenna can cause serious RF burns.
ASSEMBLY and INSTALLATION PROCEDURE
Refer to the figures in this manual during assembly. Assembly consists of installing a ground
mount, installing the base mount assembly to the ground mount, assembling the telescoped
antenna, installing the antenna to the base mount, installing the balun, radials and feedline, and
finally telescoping the antenna to its full height. Check tubing before assembly for bends,
scratches or burrs. The tubing should be smooth inside and out and should be straight. Any
burrs on the inside of the tubing where the slot is will cause the tubes to lock together if not
removed. A small amount of oil or grease can be used at the joints if you are planning to
telescope the tubing regularly. This will aid greatly in reducing the chances of the tubes locking
together.
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