M2 Antenna Systems 2M4X User manual

M2 Antenna Systems, Inc. 4402 N. Selland Ave. Fresno, CA 93722
Tel: [phone] Fax: [phone] Web: www.m2inc.com
©2022 M2 Antenna Systems Incorporated 11/29/21
Rev.01
Model .........................................2M4X
Frequency Range.......................144 To 148 MHz
*Gain ..........................................9.6 dBi
Front to back ..............................20 dB Typical
Beamwidth ...............................E=54° H=74°
Feed type ...................................“T” Match
Feed Impedance. .......................50 Ohms Unbalanced
Maximum VSWR........................1.5:1
Input Connector..........................“N” Female
Power Handling ..........................1.5 kW
Boom Length / Dia......................48” / 1”
Maximum Element Length..........40-1/2”
Turning Radius: ..........................55”
Stacking Distance.......................66” High & 80” Wide
Mast Size....................................1-1/2” to 2” Nom.
Wind area / Survival ...................0.50 Sq. Ft. / 100 MPH
Weight / Ship Wt.........................3 Lbs. / 4 Lbs.
M2 Antenna Systems, Inc.
Model No: 2M4X
FEATURES:
M2 is always trying to design and build new antennas to fit the needs of amateur radio operators. The “X” series of antennas are all designed
to keep the packaging under 48” long to minimize oversize surcharges applied by shippers. The “X” series antennas offer the same performance as its
predecessor, but with shorter boom sections. The boom sections also have a thicker wall for added strength. A side benefit of the “X” series antennas
are that they are more portable with the smaller sections. The 2M4X replaces our very popular 2M4.
Each models performance is optimized for a specific mode and frequency range, with no compromises to achieve unneeded bandwidth. The
2M4X covers 144-148 MHz .Where do you want to make yourself heard? The 2M4X is an ideal building blocks for a small turning radius, high-gain
stacked array. Great for QTH’s that won’t permit a long boom Yagi. The 2M4X can be stacked on a cross boom for the same gain increases, and the
turning radius is still a very manageable 10 ft.
The heart of these antennas is a driven element module originally designed for maritime ATS satellite service. All connectors are O-ring
sealed to the CNC machined block. Internal connections are sealed with a space-age silicone gel with nearly 4 times the dielectric strength of air. The
balun connectors are triple sealed on the coax and nut-sealed at the block connectors. The type “N” feed connector uses a gold-plated, beryllium copper
center pin.
Elements are 6061-T6 3/16” solid rod with UV stabilized polyethylene Button insulators and stainless steel keepers. Thousands of these type ele-
ments are in amateur and commercial service with NO failures! Booms are constructed of 6061-T6 aluminum alloy tubing. Other key electrical and me-
chanical components are CNC machined for accuracy and durability. All hardware is stainless steel except the U-bolts. For uncompromising perfor-
mance and long term electrical / mechanical integrity, the 2M4X is unmatched.
SPECIFICATIONS:
*Subtract 2.14 from dBi for dBd

Tools handy for assembly process: screwdriver, 11/32” spin-tite or socket, 7/16” and 1/2” end wrenches /
sockets, measuring tape.
1. Lay out the elements by length and position as shown the DIMENSION sheet. Start with the
REFLECTOR (longest) element. Balance on finger to find rough center and push on a black button
insulator to about 1/2” from center. Push the element through the holes 10" from the rear of the boom
and install the second button, snugging it up into boom. DO NOT BOTHER WITH ACCURATELY
CENTERING the element at this time and DO NOT INSTALL the stainless steel SHAFT RETAINERS
yet. This is easier to do after all the elements are installed in the boom. Install the 3/16” rod DRIVEN
ELEMENT as you did the reflector and then the DIRECTORS.
2. Now accurately center the elements. Use a tape measure to EQUALIZE the amount the element
sticking out on each side of the boom. Begin installing the stainless SHAFT RETAINERS. Use thumb
and index finger to hold a retainer over end of the 3/8 x 3” push tube (retainer dished into tube). Hold
the element firmly and start the retainer onto the rod by applying pressure with the push tube. Push
the retainer until up tight against the button insulator (Locking pliers, lightly clamped up against
opposite button insulator will help maintain center reference and keep you from pushing the first
retainer too far). Repeat for the opposite side. Continue installing retainers until all elements are
locked in place.
3. Mount the “T” MATCH BLOCK ASSEMBLY to the top of the boom using a single 8-32 X 1-1/4" screw.
Orient the block with feed connector facing the rear and balun connectors facing forward.
4. Attach balun to the Block and tighten the connectors gently using a 7/16" end wrench. A lot of torque
is unnecessary. Form the balun close to the boom and secure with a nylon cable ties. Ties should be
snug but not crushing or kinking the coax.
2M4X ASSEMBLY MANUAL

5. Install the 8-32 x 1/4” set screws (internal Allen head - tool supplied) into the SHORTING BARS.
Slide the bars onto the 3/16” rod driven element tips and then onto the Driven Element Block
Rods. Position the Shorting Bars as specified on the Dimension Sheet: 1-3/4”. Align the bars and
rods with each other and tighten the setscrews.
6. The boom to mast plate is normally mounted at the rear. Use two 1" U-bolts and the stainless nuts
and lock washers provided (cradles are not used). DO NOT OVER TIGHTEN. 2” U-bolts are
provided for mounting the antenna to your mast.
THIS COMPLETES THE ANTENNA ASSEMBLY.
7. INSTALLATION AND STACKING INFORMATION
A. To protect your investment in this high performance antenna, always use high quality coax and
connectors. Old, corroded, or poor quality materials are common sources of serious performance
losses.
B. If possible, test the antenna, connectors and feedline BEFORE installing to your mast or tower.
At 6 feet or more the antenna will exhibit VSWR similar to higher mounting heights. Set antenna
on a ladder or temporary mast. Check for continuity and match across the rated bandwidth.
C. REAR MOUNTING: The 2M4X is easily rear-mounted in either horizontal or vertical polarity. A
metal mast or crossboom will have no effect on performance.
D. CENTER MOUNTING: Metal masts or crossbooms are OK for center mounting the antenna IF
they are at right angles to the element plane. ALWAYS use a NON-CONDUCTIVE mast or
crossboom IF it will be in the element plane. A metal mast in the element plane WILL adversely
affect performance. The feed coax, too, if routed to the center, must exit the boom at right angles
to the element plane. For example, with a vertically polarized antenna on a vertical non-
conductive mast, loop the coax out at a right angle from the elements and reattach to mast at least
6” below the element tips. Or, the coax can exit the rear of the boom and loop back to the mast.
Fiberglass is the prime material for a non-conductive mast because of it’s strength and weather
resistance. Wooden rod can also be used or thick-wall PVC pipe with a wooden rod inside for
support.
Carefully manufactured by:
M2 ANTENNA SYSTEMS, INC.
4402 N. Selland Ave.
Fresno, CA 93722
[phone] Fax: [phone]
www.m2inc.com Email: [e-mail]
2M4X ASSEMBLY MANUAL

2M4X DIMENSION SHEET

DESCRIPTION QTY
BOOM, 1 X .065 X 27-1/4” ALUM (M2ABS2M4X-1).................................... 1
BOOM, 1 X .065 X 27-1/4” ALUM (M2ABS2M4X-2).................................... 1
ELEMENTS, 3/16" ROD ALUM ........................ .......................................... 4
DRIVEN ELEMENT ASSEMBLY (SADEA2MVHF1).................................... 1
BTM PLATE, 3 X 4 X 1/8” (M2APT0019).......... .......................................... 1
BALUN, RG-6................................................... .......................................... 1
U-BOLT AND CRADLE, 2" .............................. ......................................... 2
U-BOLT, 1" ...................................................... .......................................... 2
ASSEMBLY INSTRUCTIONS........................... .......................................... 1
HARDWARE BAG
SHORTING BAR (M2ASB0090) ....................... .......................................... 2
NUT, 5/16-18 SS............................................... .......................................... 4
LOCK WASHER, 5/16" SPLIT RING SS........... .......................................... 4
NUT, 1/4-20 SS ................................................ .......................................... 4
LOCK WASHER, 1/4" SPLIT RING SS ............ .......................................... 4
SETSCREW, 8-32X1/4” INT. ALLEN, SS......... .......................................... 4
SCREW, 8-32 X 1-1/4" PAN HEAD SS ............ .......................................... 3
LOCKNUT, 8-32” SS......................................... .......................................... 2
BUTTON INSULATOR 3/16" BLACK POLY ..... .......................................... 8
SHAFT RETAINER, 3/16" SS ........................... .......................................... 8
PUSH TUBE, 3 X 3/16" (RETAINER TOOL).... .......................................... 1
ALLEN WRENCH, 5/64" ................................... .......................................... 1
CABLE TIE ....................................................... .......................................... 3
M2 ANTENNA SYSTEMS, INC.
4402 N. Selland Ave.
Fresno, CA 93722
[phone] Fax: [phone]
www.m2inc.com Email: [e-mail]
2M4X PARTS & HARDWARE