M2 Antenna Systems 440-18 User manual

M2 Antenna Systems, Inc. 4402 N. Selland Ave. Fresno, CA 93722
Tel: [phone] Fax: [phone] Web: www.m2inc.com
©2015 M2 Antenna Systems Incorporated 06/09/15
Rev.03
Model .........................................440-18
Frequency Range.......................420 To 453 MHz
*Gain ..........................................16.64 dBi
Front to back ..............................23 dB Typical
Beamwidth ...............................E=27° H=32°
Feed type ...................................Folded Dipole
Feed Impedance. .......................50 Ohms Unbalanced
Maximum VSWR........................1.2:1 Typical
Input Connector..........................“N” Female
Power Handling ..........................1.5 kW
Boom Length / Dia......................137”’ / 1” To 3/4”
Maximum Element Length..........14”
Turning Radius: ..........................69’
Stacking Distance.......................51” High & 52” Wide
Mast Size....................................2”
Wind area / Survival ...................0.68 Sq. Ft. / 100 MPH
Weight / Ship Wt.........................5 Lbs. / 7 Lbs.
M2 Antenna Systems, Inc.
Model No: 440-18
FEATURES:
The 440-18 is a computer optimized broadband yagi featuring an excellent pattern and good gain across its band-
width. It can be mounted vertically or horizontally and is ideal for stacking two or more for additional gain. Its light weight
yet sturdy construction keep the cost low and the performance high. Use it for ATV, OSCAR, FM, LONG HAUL TROPO,
ETC. We guarantee you will be impressed.
The heart of the 440-18 is a unique Driven Element Module with superior weather resistance and power handling
abilities. All connectors are O-ring sealed to the CNC machined block and internal connections are sealed in a space-
age silicone gel with a dielectric strength nearly 4 times greater than air. The Balun coax connectors are triple O-ring
sealed. Other key mechanical and electrical parts are CNC machined from 6061-T6 aluminum and all hardware except U-
bolts is stainless steel.
The 440-18 offers you uncompromising performance, enduring mechanical construction, and long term electrical
integrity. Where else but M2.
SPECIFICATIONS:
*Subtract 2.14 from dBi for dBd

1. Start by laying out the boom sections using the DIMENSION sheet as a guide. Use 8-32 X 1-1/4
screws and locknuts to join sections. Sections may be swaged to fit each other or use short
internal splice sections.
2. Lay out the elements by length and position as shown the DIMENSION sheet. Start with the
reflector (longest) element and push on a black button insulator to about 1/2” from center. Push the
element through the holes 1/2" 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 internal locking “KEEPERS” yet. This is easier to do after all
the elements are installed in the boom.
3. Install the 3/16” rod DRIVEN ELEMENT as you did the reflector. Then continue with the installation
of the DIRECTORS. Note that the Director Elements do not consistently diminish in length from
rear to front, so pay close attention to length and position.
4. Now begin centering the elements. Use a tape measure to EQUALIZE the amount the element
sticking out on each side of the boom. Once you have all the elements centered, sight down the
element tips from the rear comparing each side. Look for any obvious discrepancies and correct if
found.
5. Begin installing the stainless “keepers.” Use thumb and index finger to hold a keeper over end of
the 3/8 x 3” push tube (keeper dished into tube). Hold the element firmly and start the keeper onto
the rod by applying pressure with the push tube. Push the keeper 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 keeper too far). Repeat for the opposite side.
Continue installing keepers until all elements are locked in place.
440-18 ASSEMBLY MANUAL

6. Mount the DRIVEN ELEMENT BLOCK to the boom using a single 8-32 X 1-1/4" screw and
lockwasher. Orient the block with feed connector facing to center and balun connectors facing to
rear. Block orientation may be reversed if you wish feedline to exit from rear of boom.
7. Attach balun 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 to boom with a nylon cable tie. Tie
should be snug but not crushing or kinking the coax.
8. 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 1/8” Driven Element Block Rods. Position
the Shorting Bars as specified on the Dimension Sheet: the distance given is between the outer
edge of the Driven Element Block and the inner edge of the Shorting Bar. Align the bars and rods
with each other and tighten the setscrews.
9. The boom to mast plate is normally mounted at the balance point. 1" U-bolts and the stainless nuts
and lock washers provided. DO NOT OVER TIGHTEN. 2” U-bolts are provided for mounting the
antenna to your mast. Since the feed line represents significant weight it is best to have it attached
and fastened along the boom with cable ties before balancing the boom and mounting the plate.
10. MOUNTING AND STACKING INFORMATION
Keeping metallic masts, crossbooms and the feed coax out of the element plane will help maintain
good VSWR and pattern.
FOR HORIZONTAL POLARIZATION, the 440-18 may be mounted to a metallic vertical mast or a
horizontal NON-METALLIC crossboom (no conductive material in element plane). If mounted to a
horizontal crossboom, route the feedline forward to the boom-to-mast plate, loop down, and bring
back to crossboom at least 6” beyond element tips.
FOR VERTICAL POLARIZATION, the 440-18 may be mounted to a NON METALLIC VERTICAL
MAST (no conductive material in element plane) or a horizontal metallic crossboom. If mounted to
a vertical mast, route the feed line forward to the boom-to-mast plate, loop out at a right angle to
the boom, and bring down to the mast at least 6 inches BELOW THE ELEMENT TIPS. The
feedline may also exit at the rear of the boom and loop back to the mast.
Stacking? Call M2and let us help you DO IT RIGHT
THIS COMPLETES THE ANTENNA ASSEMBLY.
CAREFULLY MANUFACTURED BY:
M2ANTENNA SYSTEMS, INC.
4402 N. Selland Ave.
Fresno, CA 93722
[phone] Fax: [phone]
www.m2inc.com Email: [email protected]
440-18 ASSEMBLY MANUAL

440-18 DIMENSION SHEET

DESCRIPTION QTY
BOOM SECTION, 1 X .058 X 57” SOE............. 1
BOOM SECTION, 1 X .058 X 60” SOE............. 1
BOOM SECTION, 3/4 X .058 X 25-1/2” ............ 1
ELEMENTS, 3/16 ROD x Dimension Sheet...... 18
DRIVEN ELEMENT BLOCK.............................. 1
BALUN, RG-6 1/2 WAVE .................................. 1
BOOM-TO-MAST PLATE, .188 X 3” X 4”......... 1
U-BOLT AND CRADLE, 2”................................ 2
U-BOLT, 1”........................................................ 2
ASSEMBLY MANUAL....................................... 1
IN HARDWARE BAG:
SHORTING BAR............................................... 2
BUTTON INSULATORS.................................... 36
KEEPER, SS..................................................... 36
NUT, 5/16-18 SS............................................... 4
LOCKWASHER, 5/16 SS.................................. 4
NUT, 1/4-20 SS................................................. 4
LOCKWASHERS, 1/4 SS.................................. 4
SETSCREW, 8-32 X 1/4, SS............................. 4
SCREW, 8-32 X 1-1/4 SS ................................. 5
LOCKNUT, 8-32 SS .......................................... 4
LOCKWASHER, #8 SS..................................... 1
CABLE TIE, NYLON ........................................ 3
ALLEN HEAD WRENCH, 5/64”......................... 1
PUSH TUBE, 3/8 X 3” ....................................... 1
CAREFULLY MANUFACTURED BY:
M2ANTENNA SYSTEMS, INC.
4402 N. Selland Ave.
Fresno, CA 93722
[phone] Fax: [phone]
www.m2inc.com Email: [email protected]
440-18 PARTS & HARDWARE