M2 Antenna Systems 2M7X User manual

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

Tel: (559) 432-8873 Fax: (559) 432-3059 Web: www.m2inc.com

Rev.00

Model .........................................2M7X

Frequency Range.......................144 To 148 mHz

*Gain ..........................................12.3 dBi

Front to back ..............................20 dB Typical

Beamwidth ...............................E=43° H=50°

Feed type ...................................“T” Match

Feed Impedance. .......................50 Ohms Unbalanced

Maximum VSWR........................1.2:1 Typical

Input Connector..........................“N” Female

Power Handling ..........................1.5 kW

Boom Length / Dia......................8’ 10” / 1”

Maximum Element Length..........40-1/2”

Turning Radius: ..........................63-1/2”

Stacking Distance.......................6’ 8” High & 7’ 3” 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: 2M7X

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” serries antennas offer the same performance as its predecessor, but with shorter boom sections. The boom sec-

tions also have a thicker wall for added strength. A side benefit of the “X” series antenna are that they are more portable

with the smaller sections. The 2M7X replaces our very popular 2M7.

The 2M7X is a computer optimized Yagi that will outperform longer old design antennas. The 2M7 covers the

whole band with only slight performance degradation at the band edges. Side lobes are very low and it is perfect for

stacking 2 or more. Its light weight and durability make it great for portable hill topping.

The 2M7X is built for long term electrical and mechanical integrity. The CNC machined “T” Match Block features

O-ring sealed connectors and is internally sealed with a space-age silicone gel with nearly 4 times the dielectric strength

of air. Elements are 6061-T6 3/16” aluminum rod, mounted through the boom on UV stabilized button insulators. All hard-

ware is stainless steel except U-bolts. Other key electrical and mechanical parts are CNC machined for accuracy and du-

rability.

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

and/or sockets, measuring tape.

1. Assemble the boom sections using the 8-32 X 1-1/4 screws and locknuts.

2. 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. Install the element through the holes at the boom and push on 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.

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 the element length 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 SHAFT RETAINER to one side of the element. Use thumb and index

finger to hold a retainer over end of the 3/8 x 3” push tube (chamfer inner edge of 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). It is a good idea to install the second SHAFT RETAINER after final

testing.

6. Mount the DRIVEN ELEMENTASSEMBLY to the underside of the boom using a single 8-32 X 1-1/4"

screw. Orient the block with feed connector facing forward and balun connectors facing to rear. Block

orientation may be reversed if you wish feedline to exit rear of boom.

7. Attach balun to the DRIVEN ELEMENT ASSEMBLY and tighten the connectors gently using a 7/16"

end wrench. Coil balun once, if necessary, so balun does not extend beyond end of boom. Form the

balun close to the boom and secure with a nylon cable tie, snug but not crushing or kinking the coax.

2M7X ASSEMBLY MANUAL

2M7X DIMENSION SHEET

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 then onto the Driven Element Block

Rods. Position the Shorting Bars as specified on the Dimension Sheet: 2-9/16” from the outer face

of the block to the inner face of the bar. Align the bars and rods with each other and tighten the set

screws.

9. The boom to mast plate is normally mounted at the balance point. Since the feedline represents

significant weight it is best to have it attached and fastened along the boom with cable ties before

final mounting of the plate. Use two 1" U-bolts and the stainless nuts and lock washers provided

(no cradles are used). DO NOT OVER TIGHTEN. 2” U-bolts are provided for mounting the

antenna to your mast. Never mount to a metallic mast or cross boom in the same plane as the

elements. Pattern and performance will deteriorate. See next step.

10. INSTALLATION AND TESTING 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. 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 band. It should be close to

“spec” across the rated bandwidth. When satisfied, add the second SHAFT RETAINERS as

described in step 5.

C. STACKING REMINDERS:

1. All driven element blocks MUST be oriented to the same side of boom.

2. All boom-to-mast plates MUST be mounted at the same point on the boom.

3. Feed / phasing lines MUST be of equal electrical length or multiples of 1/2 wavelength in order

to maintain equal phasing in the array. Improper phasing can severely deteriorate performance.

4. As a general rule, you never want to have metallic structures, such as a mast or feed lines

parallel to the elements unless it is behind the reflector. Having metallic structure in the same

plane as the elements in front of the reflector element can cause VSWR problems and or skewed

patterns.

FOR HORIZONTAL POLARIZATION, the antenna may be mounted to a METALLIC vertical mast

or a horizontal NON-METALLIC cross boom. If mounted to a horizontal cross boom, route the

feedline forward to the boom-to-mast plate, loop down, and bring back to cross boom at least 6”

beyond element tips. Antennas are typically stacked one above the other in horizontal polarity.

SEE SPEC SHEET FOR STACKING DISTANCE. See Stacking Reminders.

FOR VERTICAL POLARIZATION, the antenna may be mounted to a NON METALLIC

VERTICAL MAST or a horizontal METALLIC cross boom. If mounted to a NON METALLIC

vertical mast, Turn the driven element 180 degrees so the feed line and “N” connector is facing to

the rear of the antenna, route the feed line to the rear of the antenna keeping 4” to 6” behind the

reflector element. Let the cable droop at least 6 inches BELOW THE VERTICAL ELEMENT TIPS.

Re-attach the feed line to the mast below the element tips. A simple structure can easily be

fabricated if you want something to support the feed line. See M2 “L” brace kit for ideas. Vertically

polarized Antennas are typically stacked side by side on a horizontal cross boom. See Stacking

Reminders.

If you are unsure about stacking multiple antennas, please call M2 and let us help you DO IT

RIGHT! Visit our website, https://www.m2inc.com/blog/ for other tips.

2M7X ASSEMBLY MANUAL

DESCRIPTION QTY

BOOM SECTION, 1 X .065 X 37-1/8” SOE (M2ABS2M7X-1).................1

BOOM SECTION, 1 X .065 X 37-1/8” SOE (M2ABS2M7X-2).................1

BOOM SECTION, 1 X .065 X 35-3/4” STR (M2ABS2M7X-3) .................1

ELEMENTS, 3/16 ROD X DIMENSION SHEET .....................................1

DRIVEN ELEMENT ASSEMBLY (SADEA2MVHF1)...............................1

BALUN, RG-6 1/2 WAVE (SABAL2M144) ..............................................1

BOOM-TO-MAST PLATE, .125 X 3” X 4” (M2APT0019) ........................1

U-BOLT 1”...............................................................................................2

U-BOLT AND CRADLE, 2”......................................................................2

ASSEMBLY MANUAL.............................................................................1

IN HARDWARE BAG:

SHORTING BAR, (M2ASB0090) ............................................................2

BUTTON INSULATORS..........................................................................14

KEEPER, 3/16” SS..................................................................................14

NUT, 5/16-18 HEX SS ............................................................................4

LOCKWASHER, 5/16 SS........................................................................4

NUT, 1/4-20 HEX SS ..............................................................................4

LOCKWASHER, 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

CABLE TIE, 7” NYLON ...........................................................................3

ALLEN HEAD WRENCH, 5/64”...............................................................1

PUSH TUBE, 3/8” X 3”............................................................................1

Carefully manufactured by:

M2 ANTENNA SYSTEMS, INC.

4402 N. Selland Ave.

Fresno, CA 93722

(559) 432-8873 Fax: 432-3059

www.m2inc.com Email: sales@m2inc.com

2M7X PARTS & HARDWARE

Table of contents

Other M2 Antenna Systems Antenna manuals

M2 Antenna Systems

M2 Antenna Systems EB-144/RK2M User manual

M2 Antenna Systems

M2 Antenna Systems 6M6LN User manual

M2 Antenna Systems

M2 Antenna Systems 303CP26 User manual

M2 Antenna Systems

M2 Antenna Systems 300XP12 User manual

M2 Antenna Systems

M2 Antenna Systems 2.4-18R User manual

M2 Antenna Systems

M2 Antenna Systems 440-460-11HD User manual

M2 Antenna Systems

M2 Antenna Systems 146CP8 User manual

M2 Antenna Systems

M2 Antenna Systems 20M5-125 User manual

M2 Antenna Systems

M2 Antenna Systems FGHM64 User manual

M2 Antenna Systems

M2 Antenna Systems 440-18 User manual

M2 Antenna Systems

M2 Antenna Systems 902-5 YAGI User manual

M2 Antenna Systems

M2 Antenna Systems 6M HO LOOP User manual

M2 Antenna Systems

M2 Antenna Systems 20M6-125 User manual

M2 Antenna Systems

M2 Antenna Systems 32 HO LOOP User manual

M2 Antenna Systems

M2 Antenna Systems 35.7-4 User manual

M2 Antenna Systems

M2 Antenna Systems 6-30LP11 User manual

M2 Antenna Systems

M2 Antenna Systems FG170-230-5 User manual

M2 Antenna Systems

M2 Antenna Systems 436CP16 User manual

M2 Antenna Systems

M2 Antenna Systems 440-6SS User manual

M2 Antenna Systems

M2 Antenna Systems 295XP6 User manual

M2 Antenna Systems

M2 Antenna Systems 420-50-11 User manual

M2 Antenna Systems

M2 Antenna Systems 2M5-440XP User manual

M2 Antenna Systems

M2 Antenna Systems 440-11X User manual

M2 Antenna Systems

M2 Antenna Systems 30M3-125 User manual

Popular Antenna manuals by other brands

Alfa Network

Alfa Network APA-L01 Specifications

Naval

Naval PR-422CA Operation manual

Feig Electronic

Feig Electronic ID ISC.ANTH200/200 Series manual

TERK Technologies

TERK Technologies TV44 owner's manual

Directive Systems & Engineering

Directive Systems & Engineering DSE2324LYRMK quick start guide

HP J8999A instructions

MobilSat

MobilSat MSP-S Mounting instructions

Steren

Steren ANT-UHF 13 instruction manual

Novatel

Novatel 600-G User information

Radio Shack

Radio Shack Amplified VHF/UHF/FM Indoor Antenna owner's manual

TRENDnet

TRENDnet TEW-AO12O Specifications

Radio Shack

Radio Shack 15-1837 owner's manual

CommScope

CommScope CMAX-OMFX-43M-I53 Installation instruction

Ramsey Electronics

Ramsey Electronics DAP25 Kit assembly and instruction manual

COBHAM

COBHAM SAILOR 800 VSAT Replacement procedure

Trango Systems

Trango Systems AD900-9 Specification sheet

Steren

Steren ANT-100 user manual

Proxim

Proxim 5054-PA-23 quick start guide