The 2M5-440XP is ideal for linking repeaters and remote bases utilizing both 2 meters and 440 MHz. Elements
are cross polarized to avoid the severe performance compromises on 440 MHz common to other dual band antennas that
have all elements in the same polarity. The XP also works well on the OSCAR frequencies and is handy wherever dual
band capability and compact size are required. Recently, with PACKET users finding horizontal polarization better on 2
meters, it has become even more useful.
Construction is designed for long term mechanical and electrical integrity. The heart of this antenna is the CNCmachined Driven Element Block. Connectors are O-ring sealed and the internal con nections are encapsulated in a spaceage silicone gel with nearly 4 times the dielectric strength of air. Balun connectors are triple sealed and nut-sealed at the
block connectors. Elements are 3/16” 6061-T6 aluminum rod, centered through the boom on UV stabilized insulator
buttons. All hardware except U-bolts is stainless steel (S.S. nuts and lockwashers are supplied for them, too).
M2 Antenna Systems, Inc. 4402 N. Selland Ave. Fresno, CA 93722
TOOL REQUIRED FOR ASSEMBLY: Screwdriver, 11/32 nut driver or wrench, 7/16” and 1/2” end
wrenches, pliers, measuring tape.
1. Assemble 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 each other or use 7/8” internal splice
sections.
ASSEMBLING THE 440 MHz ELEMENTS
2. Lay out the elements by length and position as shown the DIMENSION sheet. Start with the
reflector (longest) element. Balance it on your finger to find rough center and push on a black
button insulator to about 1/2” off 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 CENTERING
the element at this time and DO NOT INSTALL the stainless steel internal locking “keepers” yet. It
is easier to do it after all the horizontal 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.
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.
Page 5
2M5-440XP ASSEMBLY MANUAL
6. Mount the 440 MHz DRIVEN ELEMENT BLOCK / ROD ASSEMBLY to the TOP of the boom using a single 8-
32 X 1-1/4" screw and lockwasher. Orient the block with the two balun connectors facing to front, “N”
connector to rear. Reverse for center mounted antenna.
7. Install the 8-32 x 1/4” set screws (internal Allen head - tool supplied) into the SHORTING BARS. Slide the bars
onto the 1/8” Driven Element Block Rods and the 3/16” Driven Element Rods. Position the inner edge of each
Shorting Bar 4-3/8” from the outer edge of the Driven Element Block (see Dimension Sheet). Align the bars
with each other and tighten the set screws.
ASSEMBLING THE 2 METER ELEMENTS
8. Repeat steps #2 through #5 for the 2 meter elements, using the Dimension Sheet as your guide to lengths and
spacing.
9. Mount the 2 Meter Driven Element Block to the left hand side of the boom with the two Balun connectors
oriented to the FRONT, “N” connector to rear. Reverse for center mounted antenna. Secure with 8-32 x 1-1/4”
screw and lockwasher. Install the Shorting Bars as in step #7.
10. Before installing the Baluns, thread 3/8” SEAL NUTS fully onto all connectors, with the black Neoprene face of
the nuts facing out. Attach Baluns to the Driven Element Blocks as shown on the Dimension Sheet. 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 and will damage seal. Depending on mounting options, a balun may loop around other
elements. This is normal. Form balun coax until it is close to the boom and secure with a nylon cable tie. Also
secure the other balun. Ties should be snug but not crushing or kinking the coax.
REAR MOUNTING
11. The boom to mast plate is mounted at the rear of boom using two 1" U-bolts and the stainless nuts and lock
washers provided. Rotate to desired polarity. DO NOT OVER TIGHTEN. 2” U-bolts are provided for mounting
the antenna to your mast, tower leg, or crossboom.
CENTER MOUNTING
12. Find the balance point and mount the boom to mast plate with the 1” U-bolts. Since one set of elements will be
in the plane of the mast, a non-conductive mast of fiberglass or equivalent is strongly recommended. 2” Ubolts are provided for mounting the antenna to your mast, tower leg, or crossboom.
13. Use good quality coax and “N” connector for your feedlines. Secure feed coax near connectors with cable ties
to provide stress relief. Then route tight against boom (AVOID TOUCHING THE ELEMENTS WITH THE
FEEDLINES and secure again with ties or black electrical tape at exit point.
THIS COMPLETES THE ANTENNA ASSEMBLY.
www.m2inc.com Email: sales@m2inc.com
2
M
ANTENNA SYSTEMS, INC.
4402 N. Selland Ave.
Fresno, CA 93722
(559) 432-8873 FAX: 432-3059
Page 6
2M5-440XP PARTS & HARDWARE
DESCRIPTION QTY
BOOM SECTION #1, 1 X .058 X 60” SOE............... 1
BOOM SECTION #2, 1 X .058 X 11-1/2” STR......... 1
DRIVEN ELEMENT BLOCK, 2 METER................... 1
DRIVEN ELEMENT BLOCK, 440 MHz.................... 1