M2 Antenna Systems 6M7JHVHD 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 Incoporated 12/21/09
Rev.00
Model .........................................6M7JHVHD
Frequency Range.......................50.0 To 50.4 mHz
*Gain ..........................................13.04 dBi
Front to back ..............................25 dB Typical
Beamwidth ...............................E=40° H=42°
Feed type ...................................“T” Match
Feed Impedance........................50 Ohms Unbalanced
Maximum VSWR........................1.2:1
Input Connector..........................“N” Female
Power Handling..........................1.58 kW
Boom Length / Dia......................30’ 8” / 2”
Maximum Element Length..........102-3/8”
Turning Radius:..........................206”
Stacking Distance.......................25’ High & 27’ Wide
Mast Size....................................2” Nom.
Wind area / Survival...................4.2 Sq. Ft. / 100 MPH
Weight / Ship Wt.........................22 Lbs. / 24 Lbs.
M2 Antenna Systems, Inc.
Model No: 6M7JHVHD
FEATURES:
The 6M7JHVHD is HEAVY DUTY version of the 7 element antenna designed originally for Dave Batcho, N5JHV. The
JHV's excellent gain is coupled with a very clean pattern for reducing local noise, making it ideal for long-haul terrestrial
and EME communications. An outstanding performer by itself, the JHV also produces 17 dBd in an 4-bay array. Mechan-
ical features include machined aluminum element-mounting blocks, O-ring sealed connectors and balun, silicone-gel
sealed T- match block, and stainless steel hardware. Elements are 3/8 tube and DC grounded. The 2" boom come in 95
in. sections for UPS but now strong enough to handle 100 mph winds or heavy ice load. An overhead guy system pro-
vides additional boom support.
SPECIFICATIONS:
*Subtract 2.14 from dBi for dBd

TOOLS REQUIRED: Phillips screwdriver, 11/32 wrench, socket or spintite, a 7/16" and 1/2" wrench or
socket, tape measure.
1. Layout the boom sections as shown on Dimension Sheet and assemble with 1/4-20 x 2-1/‘2" bolts
and locknuts. Tighten the nuts securely.
2. Use the Dimension Sheet as reference for installing the ELEMENT HALVES on to the ELEMENT
MOUNTING BLOCKS. For each element insert a 1/4 x 10” Element Support Rod from the drilled end.
Secure the rod / element assemblies to the element mounting blocks with the 8-32 x 1" screws and
locknuts. Install screws from bottom of blocks.
3. Mount the longest element (REFLECTOR) to the hole at the rear end of the boom using a 1/4-20 x
2-3/4” bolt and locknut. Tighten securely.
4. Mount the DRIVEN ELEMENT next, threading the 2-1/2” bolt though the element block and into the
'T' MATCH BLOCK held to the underside of the boom. Orient the match block with the “N” feed
connector pointed to the front.
5. Mount the remaining DIRECTOR ELEMENTS using the element lengths specified on the
Dimension Sheet. The element lengths taper in this design.
6. Thread the gold SEAL NUTS all the way onto the two small connectors on the 'T' match block with
the black neoprene side out. Then connect the balun connectors and tighten them GENTLY
with a 7/16" end wrench. Now run the seal nuts up against the face of the balun connectors and
tighten them about 1/2 turn with a 1/2" end wrench. Secure coiled balun to boom with two nylon ties.
6M7JHVHD ASSEMBLY MANUAL

7. Install two 8-32 x 1/4” Set screws into each SHORTING BAR. Then slide a SHORTING BAR onto
each DRIVEN ELEMENT HALF and position per the dimension sheet. Align rods and element halves
parallel and tighten the set screws with the 5/64" Allen wrench provided. NOTE: The half wave length
balun does not have to be coiled up to work. It can be uncoiled and run along the boom backwards or
preferably forward to move its weight more toward the center of the boom.
8. Install the main feedline, or a pigtail section just to get to the middle of the boom. Tighten the Male
'N' connector carefully, and route the cable forward on the boom, securing it with the cable ties
provided.
9. Mount the BOOM TO MAST PLATE perpendicular to elements at the physical balance point of the
antenna with the feedline installed. Secure with the 2" U-bolts, 5/16” stainless steel lockwashers and
nuts. Tighten the U-bolts just enough to fill the saddles. Over-tightening can deform and weaken the
boom. . 2” U-bolts are supplied for attaching plate to your mast.
10. Install the 1/4” x 4” EYEBOLTS to the front and rear boom sections, eyes up and parallel with
boom. Secure with 1/4-20 locknuts.
11. To prepare the overhead guy system, begin by temporarily installing a 2” U-bolt through the 2” x 4”
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 in place. Unscrew turnbuckle eyes / hooks until only a thread or two shows inside
the turnbuckle body and hook to turnbuckle plate.
12. 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.
13. Equalize cord length at turnbuckle plate and cut. Put two turns trough rear turnbuckle eye, pull
slack out of rope, and add three TIGHT half-hitches. Repeat for front cord section. Seal and tape cord
ends.
14. Both cords should now be fairly taut and parallel with boom. Disconnect the 2” U-bolt securing the
turnbuckle plate and lift the turnbuckle plate up until the boom bows up slightly. This is approximately
how high the plate will need to be mounted on the mast when the antenna is installed.
15. 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”, readjust the
turnbuckle plate height until boom is straight and level. Finer adjustments can be made at any time, if
necessary, with the turnbuckles. Safety-wire the turnbuckles to preserve settings.
16. When the antenna is installed in position on the mast, the main feedline can be attached and
sealed at that time. 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 HF
models, maintain a minimum 5’ of separation; more if practical. Mount horizontally polarized VHF and
UHF antennas at least 40” above or below this antenna to minimize interaction.
6M7JHVHD ASSEMBLY MANUAL

17. INSTALLATION AND STACKING INFORMATION
A. A mast or crossboom that is mounted to the boom in the element plane must be non
conductive (fiberglass, etc).
B. 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.
C. If possible, test the antenna, connectors and feedline BEFORE installing to your mast
or tower. Set antenna on a tall ladder or temporary mast. Check for continuity and match across
the bandwidth. It should be similar to rated specifications.
D. 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 wavelength in order to
maintain equal phasing in the array. Improper phasing can severely deteriorate performance.
4. If you are unsure about stacking multiple antennas, please 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]
6M7JHVHD ASSEMBLY MANUAL

6M7JHVHD DIMENSION SHEET

DESCRIPTION QTY.
Boom Section #1 to #3, 2 x .065 x 95" SOE Alum. 3
Boom Section #4 2 x .065 x 95" plain. Alum. 1
Element half, 3/8 x .049 x see DIMENSION SHEET 14
Element Support Rod, 1/4 x 10” 14
Driven `T' Match Assembly 1
Balun, 4:1, 1/2 wavelength @ 50.1 MHz, RG-6 1
Dacron rope, 3/16” x 24’ 1
Boom Plate 4 x 6 x 3/16 Alum. 1
Assembly Instructions 1
HARDWARE BAG#1
U-Bolt2" 5
HARDWARE BAG #2
Element mounting blocks, 3/8 x 3/4 x 3” machined alum. 7
Turnbuckle plate, 1/8 x 2 x 4” alum. 1
Turnbuckle, hook and eye, 5/16” 2
Eyebolts, 1/4 x 4” 2
HARDWARE BAG #3
Shorting bar, 1/4 x 3/4 x 3-3/8” mach. alum. 2
Nuts 5/16-18 ss 10
Lockwashers 5/16 Split Ring, ss 10
Bolt, 1/4-20 x 2-3/4”,ss 6
Bolt, 1/4-20 x 2-1/2”,ss 7
Nuts, 1/4-20 locking, ss 14
Screw 8-32 x 1" panhead ss 14
Set Screw Internal Hex 8-32 x 1/4 ss 4
Locknut 8-32 ss 14
NutSeals 2
Cable Ties 14" Black 5
Allen Wrench 5/64 1
M2ANTENNA SYSTEMS, INC.
4402 N. Selland Ave.
Fresno, CA 93722
[phone] Fax: [phone]
www.m2inc.com Email: [email protected]
6M7JHVHD PARTS & HARDWARE