M2 Antenna Systems 10M7DX User manual

M2 Antenna Systems, Inc. 4402 N. Selland Ave. Fresno, CA 93722
Tel: [phone] Fax: [phone] Web: www.m2inc.com
©2018 M2 Antenna Systems Incorporated
7/16/18
REV A
Model ........................................ 10M7DX
Frequency Range ...................... 28.0 To 29.0 MHz
*Gain, (FS) / Over gnd............... 12.4dBi / 17.6dBi @35’
Front to back.............................. 25 dB Typical
Beamwidth ............................... E=43° / H=50°
Feed type................................... Hair pin match
Feed Impedance........................ 50 Ohms Unbalanced
Maximum VSWR ....................... 1.2:1
Input Connector ......................... SO-239, Others avl.
Power Handling ......................... 3 kW, Higher avl.
Boom Length / Dia ..................... 45’ 2” / 2-1/2” To 2”
Element Length / Dia. ................ 18.5’ / 1” To 1/2”
Turning Radius: ......................... 26’
Stacking Distance ...................... 35’
Mast Size ................................... 2” to 3 ” Nom.
Wind area / Survival................... 6 Sq. Ft. / 100 MPH
Weight / Ship Wt........................ 49 Lbs. / 60 Lbs.
M2 Antenna Systems, Inc.
Model No: 10M7DX
FEATURES:
The 10M7DX was designed for the DX’er using computer optimization techniques. Performance is excellent on
both the CW and phone. The pattern is sharp and clean reducing noise and QRM. The 10M7DX is a band opener and
closer. It makes 100 watts sound like a kW! Mechanically, CNC machined aluminum (6061-T6) ring clamps ground the
elements to the boom and make assembly a snap. A hairpin type match couples the 3 kW 1: balun to the feed line. The
antenna is completely DC grounded. Great effort has been put into making sure this antenna stays in the air for years to
come while providing enjoyment and satisfaction along the way. The 10M7DX is destined for the DX antenna HONOR
ROLL!
SPECIFICATIONS:
*Subtract 2.14 from dBi for dBd / FS = Free Space

Note: A cup of zinc paste (PENETROX, NOALOX, or equivalent) has been provided to enhance the
quality of all the electrical joints in this antenna. Apply a thin coat wherever two pieces of aluminum
come in contact PARTICULARLY IN THE DRIVEN ELEMENT MATCHING ASSEMBLY.
BOOM SETUP AND ASSEMBLY
1. Refer to the Dimension Sheet. Note the different boom sections and the approximate position of
each element. Lay out the boom sections in order of assembly but do not couple together yet. Slide
the appropriate size and number of RING CLAMPS into their approximate positions on ALL boom
sections. For example, the rear boom section, 2” x 95”, has three 2” ring clamps. Spread the ring
clamp fingers with a flat blade screwdriver to ease movement on boom. Loosely add a 1/4-20 x 1” bolt
and locknut to fingers of all clamps. After all 7 ring clamps have been put into their relative positions,
GO AHEAD AND ASSEMBLE THE BOOM. Add the two EYEBOLTS and tighten in place. Then
POSITION each ring clamp accurately starting with the rear ring clamp about 1/2” in from the end of
the boom. Final element alignment can be done once the antenna is fully assembled.
DRIVEN ELEMENT ASSEMBLY
2. Locate the two 1” x 12” swaged tube sections. Insert a 3/4 x 36” section into the swaged end and
add the 8-32 x 1-1/4” screws and locknuts. SPACE PERMITTING, add the correct set of 1/2” tips and
secure with 5/8” COMPRESSION CLAMPS (See compression clamp & tip assembly detail sheet).
Locate the 7/8 x 15” center fiberglass section and slip the two white polyethylene rings on the rod
centering them between the outer and inner holes on each side. Slide the two half element sections
over the 7/8 x 15” center fiberglass rod insulator and add the 1/4-20 x 2” bolts and locknuts loosely
through the outer holes in the rod. Locate the balun mounting plate and drop two 1/4-20 x 2” bolts
through the smaller holes in the plate and then down through the inner holes in the rod. Set this
assembly onto the driven element ring clamp. Add the 1/4" locknuts and tighten. Mount the 1:1 balun
to the plate using one 2-1/2” U-bolt and saddle. Orient the balun so the drain/vent hole is down and
tighten the U-bolt gently.
3. Locate the 1/2” wide balun straps and connect one to each side of the balun finger tight. Now
remove the loose bolts holding the element halves to the rod and insert the bolts up from the bottom,
through the rod and element butt. Place two clamp blocks on each stud. Place the balun strap on the
remaining stud and add the nuts loosely.
4. Locate the band clamp and insert a 1/4-20 x 2” bolt through the hole from the inside. Add the 3/8” x
1” spacer tube to the bolt and set the shorting bar on the spacer. Add a locknut and finger tightnen.
Slide the long, straight ends of the 3/8” hairpin tubes through the shorting bar and add the 1/4-20 x
1/4” set screws to each end of the shorting bar but don’t tighten yet. Set the open band clamp on the
boom just in front of the driven element and feed the hairpin tubes into the clamp block openings until
they are flush with the back edges. Align the tubes and begin to tighten up the clamp block bolts.
5. Adjust the shorting bar position,(see dimension sheet) align and tighten the set screws. Now
tighten the band clamp. RECHECK and tighten all the hairpin match assembly and driven element
assembly hardware, including the balun studs.
PARASITIC ELEMENT ASSEMBLY
6. Assemble the other six pairs of elements and set each on the correct ring clamp on the boom.
NOTE THERE ARE TWO 1” TUBE SECTIONS THAT ARE DRILLED TO FIT THE 2-1/2” RING
CLAMPS. BE SURE THE RIGHT TIPS ARE INSTALLED IN THESE ELEMENTS Note: Directors 2
and 3 mount to 2-1/2” ring clamps.
10M7DX ASSEMBLY MANUAL

OVERHEAD GUY ASSEMBLY
7. If possible, attach the feedline to the balun and route it forward to about 18 feet from the rear of the
boom. Seal the connector with black tape, coax seal or equivalent. Now pick up the antenna and mark
the balance point. It should be about 18-1/2 feet from the rear of the boom Center the BOOM TO
MAST PLATE here and secure to the boom with two 2-1/2" U-bolts, cradles, stainless lockwashers
and nuts. 2” U-bolts are supplied for attaching the antenna to the mast.
10. To prepare the overhead guy system, begin by temporarily installing a 2” U-bolt through the
TURNBUCKLE PLATE and into the top set of 2” U-bolt holes on the boom to mast plate. Add a couple
of 5/16” nuts to hold it in place. UNSCREW the turnbuckle eyes / hooks until only a thread or two
shows inside the turnbuckle body and hook them to turnbuckle plate.
11. Uncoil DACRON CORD. Secure one end to rear eyebolt, taking two turns through the eyebolt,
then adding three TIGHT half-hitches. Pull hard on cord to set the knots. Repeat for the front eyebolt.
Seal cord ends with heat (lighter, propane torch, etc) and tape to main length.
12. Equalize cord length at turnbuckle plate and cut. Put two turns trough rear turnbuckle eye. Pull the
Dacron rope as tight as possible and add three TIGHT half-hitches. Repeat for front cord section. Seal
and tape cord ends. When finished the overhead guys should be taught and laying parallel with the
boom. Now remove the turnbuckle plate from the boom to mast plate and lift it temporarily to note the
approximate height at which the boom becomes level. ( usually about 3 feet).
14. During final installation on the tower / mast, secure the turnbuckle plate at the appropriate height
with the 2” U-bolt. Then lean or pull on the cords to increase the tension and help the knots take their
final “set.” Make sure the knots are not slipping. When the guy system has taken a “set”, loosen the 2”
U-bolt and adjust turnbuckle plate height until boom is straight and level. Finer adjustments can be
made with the turnbuckles at any time, if necessary.
15. This completes the ASSEMBLY. REMEMBER to support the feedline at the antenna boom and on
the mast. Leave an adequate feedline loop for rotation around the tower. When stacking this
antenna with other H.F. models, maintain at least 8’ separation; more if practical. Mount
horizontally polarized VHF and UHF antennas at least 40” above or below this antenna to minimize
interaction.
Carefully designed and manufactured by:
M2 ANTENNA SYSTEMS, INC.
4402 N. SELLAND AVE
FRESNO, CA 93722
[phone] FAX: [phone]
www.m2inc.com Email: [e-mail]
10M7DX ASSEMBLY MANUAL

10M7DX DIMENSION SHEET
62.813
EXPOSED TIP
LENGTH

10M7DX ASSEMBLY DETAILS

GENERIC COMPRESSION CLAMP DETAIL

DESCRIPTION QTY
BOOM SECTION, 2 X .058 X 95” STRAIGHT.......................................... 1
BOOM SECTION, 2 X .058 X 87” STRAIGHT.......................................... 1
BOOM SECTION, 2 X .058 X 95’ SWAGED ONE END........................... 1
BOOM SECTION, 2-1/2 X .065 X 95” SWAGED ONE END .................... 2
BOOM SECTION, 2-1/2 X .065 X 95” SWAGED BOTH ENDS ............... 1
ELEMENT SECTION, 1” X 24 SBE FOR 2” RING CLAMP...................... 4
ELEMENT SECTION, 1” X 24 SBE FOR 2-1/2” RING CLAMP ............... 2
ELEMENT SECTION 1” X .058 X 12” SOE .............................................. 2
ELEMENT SECTION, 3/4” X .049 X 36” SOE ........................................ 14
ELEMENT TIP SECTION 1/2” X .049 X SEE DIMENSION SHEET ...... 14
FIBERGLASS INSULATOR 7/8” X 15” ROD............................................ 1
BALUN, 1:1 3-30 MHZ ............................................................................. 1
HAIRPIN TUBE 3/8 X 26” ......................................................................... 2
HARIPIN KIT BAG INCLUDING:
STRAP, BALUN, 1/2 X .050 X 4” ......................................................... 2
PLATE, BALUN MTG. 1/8 X 2 X 4” ALUM. ......................................... 1
U-BOLT, 2-1/2” AND SADDLE ............................................................ 1
CLAMP BLOCK, FOR 3/8”................................................................... 4
SHORTING BAR, HAIRPIN, 1/2 X 1/2 X 5.......................................... 1
POLY DISC, 7/8” HOLE....................................................................... 2
BAND CLAMP, MODIFIED WITH 1/4” HOLE #32 (2.0 MAX DIA) ...... 1
SPACER, 3/8 X 1” ALUM. ................................................................... 1
NUT, 5/16-18 SS.................................................................................. 2
LOCKWASHER, 5/16” SPLIT RING, SS ............................................. 2
BOLT, 1/4-20 X 2” SS .......................................................................... 3
NUT, 1/4-20 LOCKING, SS ................................................................. 3
SET SCREW, 1/4-20 X 1/4” SS........................................................... 2
ALLEN WRENCH, 1/8" ........................................................................ 1
RING CLAMP, 2” ...................................................................................... 5
RING CLAMP, 2-1/2” ................................................................................ 2
BOOM TO MAST PLATE, 6” X 8” X 1/4” .................................................. 1
TURNBUCKLE PLATE, 3/16 X 2 X 5” ...................................................... 1
DACRON CORD, 5/16”, 38’...................................................................... 1
EYEBOLTS, 5/16” X 4” ............................................................................. 2
TURNBUCKLES, 3/8”, HOOK & EYE....................................................... 2
U-BOLT AND CRADLE, 2 INCH............................................................... 5
U-BOLT AND CRADLE, 2-1/2” ................................................................. 2
COMPRESSION CLAMP, 5/8” ............................................................... 14
ASSEMBLY INSTRUCTIONS .................................................................. 1
10M7DX PARTS & HARDWARE

HARDWARE BAG
NUT, 5/16-18 SS .....................................................................................14
LOCKWASHER, SPLIT RING 5/16"........................................................14
BOLT, 1/4-20 X 3” SS................................................................................4
BOLT, 1/4-20 X 2-1/2" SS .........................................................................6
BOLT, 1/4-20 X 2” SS..............................................................................14
BOLT, 1/4-20 X 1" SS................................................................................7
NUT, 1/4-20 LOCKING, SS .....................................................................31
SCREW, 8-32 X 1-1/4" SS ......................................................................28
SCREW, 8-32 X 1/2" SS .........................................................................14
NUT, 8-32 LOCKING, SS ........................................................................28
NUT, 8-32, SS .........................................................................................14
NYLON TIE, LARGE BLACK, 11” .............................................................6
ZINC PASTE, 1 OZ. CUP..........................................................................1
M2 ANTENNA SYSTEMS, INC.
4402 N. Selland AVE
FRESNO, CA 93722
[phone] FAX: [phone]
www.m2inc.com Email: [e-mail]
10M7DX PARTS & HARDWARE