M2 Antenna Systems 2M4 Assembly Manual

M2 Antenna Systems, Inc.

Model No: 2M4

SPECIFICATIONS:

Model ......................................... 2M4

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

*Subtract 2.14 from dBi for dBd

Power Handling .......................... 2.5 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.

FEATURES:

Clean mechanical design, full band coverage and computer optimized performance make the 2M4 an exceptional
antenna. A totally sealed and grounded driven element design with a unique internal balun provides the heart that will
beat for years to come. It is perfect for base and portable use, with FM, Packet or SSB. Every station needs one!!!

M2 Antenna Systems, Inc. 4402 N. Selland Ave. Fresno, CA 93722

Tel: [phone] Fax: [phone] Web: www.m2inc.com

©2015 M2 Antenna Systems Incoporated

05/26/15

Rev.01

2M4 ASSEMBLY MANUAL

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. Before installing the balun, thread a 3/8” SEAL NUT all the way onto each connector, with the black
Neoprene face of the nuts facing out. Attach balun to the Block and tighten the connectors gently
using a 7/16" end wrench. Once the connectors are tight, back the Seal Nuts out and finger-tighten
firmly up against the face of the connectors (or tighten gently with 1/2” end wrench). A lot of torque is
unnecessary. Form the balun close to the boom and secure with a nylon cable tie. Tie should be snug
but not crushing or kinking the coax.