Cushcraft MA8040V Instructions manual

Assembly and Installation Instructions

Appendix 1: How to make a Current-Choke Balun using a Toroid Form:

A current-choke style balun may be used to prevent the antenna’s feedline from interacting with the antenna
and radial system. Best SWR performance was obtained with a choke similar to the one shown here

Feedline Choke

Use

RG-58 for low power or

RG-303 for high power

12 - 14 Turns coax on

2.4" OD Toroid Core

Amidon Associates

FT240-73

or

Fair-RIte

5977003801

3.5-4.0 MHz, 7.0–7.3 MHz
50-Ohms

1.1:1 typical at resonance
100 kHz on 80/75 meters, 300 kHz on 40 meters
23-27 feet (adjustable for 3.5 – 4.0 MHz coverage)

9.0 LB (4.1 kg.)
0 dBi @ 3.5 MHz, 2 dBi @ 7 MHz
Eight recommended (4 x 65’, 4 x 35’)

installed at the antenna base.

MA8040V Specifications:

Frequency Coverage:
Impedance:
SWR:
Bandwidth (2:1 SWR)
Height:
Weight:
Typical Gain:
Ground Radials:

Limited Warranty:

Cushcraft Corporation, 48 Perimeter Road, Manchester, New Hampshire 03103, warrants to the original
consumer purchaser for one year from date of purchase that each Cushcraft antenna is free of defects in
material or workmanship. If, in the judgment of Cushcraft, any such antenna is defective, then Cushcraft
Corporation will, at its option, repair or replace the antennas at its expense within thirty days of the date the
antenna is returned (at purchaser’s expense) to Cushcraft or one of its authorized representatives. This
warranty is in lieu of all other expressed warranties, and implied warranty is limited in duration to one year.
Cushcraft Corporation shall not be liable for any incidental or consequential damages which may result from
a defect. Some states do not allow limitations on how long an implied warranty lasts or exclusions or
limitations of incidental or consequential damages, so the above limitation may not apply to you. This
warranty gives you specific legal rights and you may also have other rights which vary from state to state.
This warranty does not extend to any products which have been subject to misuse, neglect, accident, or
improper installation. Any repairs or alterations outside of the Cushcraft factory will nullify this warranty.

48 Perimeter Road

Manchester, NH 03103

603-627-7877

FAX [phone]

SPECIFICATIONS SUBJECT TO CHANGE WITHOUT NOTICE

Cushcraft MA8040V Dual-Band Vertical Antenna

80 – 40 Meter Vertical Monopole Antenna

956358_GF_AA

MA8040V General Description: The MA8040V is a self-supporting monopole-style vertical for 80 and 40

meters. Parallel L/C resonators provide automatic bandswitching with full-band coverage from 7.0 – 7.3 MHz
and adjustable tuning to any 100-kHz segment between 3.5 – 4.0 MHz. Heavy-duty loading coils and
resilient stainless capacitive hats deliver high efficiency while handling up to 1500-Watts PEP. Designed
especially for DX operation, the radiation pattern provides a low launch angle to favor distant contacts and a
deep overhead null to cancel unwanted local QRM. The MA8040V weighs only 9 pounds for safe handling
and ease of installation.

Parts List: Before assembling, read manual thoroughly and check contents against the parts list below:

X

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Quan.

18
1
3
2
4
1
45
27
4
2
10
2
4
12
1
4
3
1
1
1
1
1
4
8
3
2
2
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1

Part # Description

010009
010040
010123
010231
010120
014764
010011
011941
360941
320056
100449
194173
105630
056249
055105
030412
030407
MA8040VJ1
902428
156336
MA8040VCA2 80-meter loading coil assembly
MA8040VCA1 40-meter loading coil assembly
226442
226443
194174
196242
195393
196230
290326
296357
096359
126228
126241
MA8040VBAT Aluminum base radiator section-1, 1-3/8” OD x 36” tube
MA8040VBB
MA8040VBC
MA8040VBD
MA8040VBE
MA8040VBAB Aluminum base support section, 1-3/8” x 12” tube
MA8040VBF
MA8040VBG
MA8040VBH

5/8” x 8-32 screw
1-1/4” x 8-32 screw
1-1/2” x 8-32 screw
1-3/4” x 8-32 screw
2” x 8-32 screw
2-1/4” x 8-32 screw (Philips Head)
Hex nut, 8-32
Split lock washer, #8
Flat aluminum spacer washer, #10
Aluminum spacer, 1/4” x 5/16” OD
Star-locking solder lug
Small 90-degree aluminum bracket
1/2” x 1/4” OD loading coil standoff spacer.
Vinyl radial-rod cap
1/4” ID black vinyl tip cap
Large worm clamp
Small worm clamp
Formed jumper wire
Braid strap
1/2” ID tuning stub bushing

Stainless steel radial-rod stock, 0.1” X 25”
Stainless steel radial-rod stock, 0.1” X 31”
8-hole radial ring
Upper radial ring support bracket
Lower radial clip
Lower radial clip support bracket
Danger label
MA8040V Product Label
Radial wire kit (400’ spool, #18 solid enamel)
Fiberglass resonator support, 1” OD x 29-1/2’” tube
Fiberglass base insulator, 1.25” OD x 16” tube

Aluminum radiator splice section, 1-1/4” x 12” tube
Aluminum radiator section-2, 1-3/8” x 72” tube
Aluminum radiator section-3, 1-1/4” x 72” tube
Aluminum radiator section-4, 1-1/8” x 72” tube

Aluminum resonator stub section-1, 1/2” OD x 23-7/8” tube
Aluminum resonator stub section-2, 3/8” OD x 23-7/8” tube
Aluminum resonator stub section-3, 1/4” OD x 23-7/8” aluminum rod

Step-16: Tune-up and test

Use a handheld SWR analyzer or transceiver with SWR meter to set up the MA8040V. If your radio has an
auto tuner, turn it off while making adjustments. To lower the antenna for top-section adjustments without
disrupting ground radials, loosen worm clamp and separate sections 1 and 2 (see Figure-16 below).

[ ] 80 meters: Adjust top section for minimum SWR at center of desired 100-kHz segment. Tuning may
vary with different ground conditions and depending on proximity of other conductors. For best SWR at low
end of band, clamp hat rods for maximum extension from the radial ring to increase hat diameter (refer back
to Step-10 Fig-10). This setting lowers tuning range by 50 kHz. For best SWR performance at top of band or
MARS coverage, set hat rods for minimum extension and remove one rod. Removing a rod increases range
by 100- kHz). Use Graph-1 below as a guideline for your initial resonator setting:

72"

66"

60"

54"

Resonator

Length

Graph-1: Suggested 80-meter Resonator Settings

48"

42"

36"

30"

24"

3.5 3.6 3.7 3.8 3.9 4.0

Frequency MHz

Minimum Hat-Rod Extension
Maximum Hat-Rod Extension
Minimum Extension, 1 Rod Removed

[ ] 40 meters: SWR should measures 2:1 or less across the entire 40-meter band with the 25” hat-rods

provided. Tuning the 80-meter resonator will have little or no impact on 40-meter tuning.

To lower antenna for tuning,

separate element at top

of first section.

Support antenna with saw horse,

small ladder, etc.

while adjusting.

Figure-16: Handling antenna for tuning operation

Avoid tuning the MA8040V in wet weather—water droplets on coils and radiator surfaces will lower operating
frequency artificially and result in mistuning.

Step 14: Install Antenna on Base Section

1

[ ] Slip a large worm clamp on top of base section, positioning below split in tube (see Figure-14).
[ ] Carefully raise vertical radiator and insert splice tube into the base section.
[ ] Slide worm clamp into position over split in tube and tighten in place.

Handling Precautions:

During installation, always use the buddy system to avoid injury and prevent antenna damage. Also, never
attempt to raise an antenna near a power line or in high winds.

030412

Large Worm clamp

Raise antenna and
insert top section

into base section.

Assembly Instructions- MA8040V

Step 1: Using the following items, install aluminum tubes on base insulator.

1
1
1
2
2
2

[ ] Identify lower end of base insulator (two through-holes, 90-degrees offset).
[ ] Install slotted end of 12” base tube on insulator and align screw holes.
[ ] Insert 1-3/4” screw at A. Secure with lock washer and nut.
[ ] Install 36” antenna section #1 over other end of insulator and align screw hole.
[ ] Insert a 1-3/4” screw at B. Secure with a lock washer and nut.

MA8040VBAB 12” x 1-3/8” OD aluminum base section
MA8040VBAT 36” x 1-3/8” OD aluminum antenna section #1
126241
010231
010011
011941

16” x 1-1/4” OD fiberglass base insulator
1-3/4” x 8-32 screw
#8 nut
#8 lock washer

Split LW

Nut

Middle

BAT

Antenna

Tube

Insulator

Align

Holes

1" Gap

B

1-3/4" x 8-32

Top

Secure with
worm clamp.

Slide large worm

clamp on tube

Figure-14: Raising Antenna

Step-15: Connect feedline to antenna base.

2

100449

Solder lug

Prepare coax, as shown in Figure-15. Attach center conductor to main radiator and shield to ground radial
ring using solder lugs. For best weather protection, flood braid with a weather-resistant liquid sealant such
as Liquid Tape™. This will prevent water from entering the coax and wicking along the shield. Coil several
turns of coax next to the antenna base or install a choke balun at the feed point (see Appendix-1 for choke­balun fabrication instructions). Feedline leading to station may be buried between radials.

Cable Pigtail

Coax Connection

Center Conductor

Shield

1-3/4"

Bottom

BAB

Base

Tube

Align

Holes

1-3/4" x 8-32

A

Figure-1: Base Insulator Assembly

Step-2: Using the following items, assemble and install ground-radial attachment ring.

1
8
9
9
2
1
2

014764
010009
011941
010011
320056
194174
194173

2-1/4” x 8-32 SS screw
5/8” x 8-32 SS screw
#8 lock washer
#8 nut
1/4” spacer
8-hole radial ring
Small 90-degree aluminum bracket

[ ] Find the 2-1/4” screw, two small 90° angle brackets, and two 1/4” spacers.
[ ] Note that 90° angle brackets have unequal sides. Identify short side of each.
[ ] Install bracket (short side) and a 1/4” spacer on the 2-1/4” screw.
[ ] Insert screw through base tube as shown at A.
[ ] Install other 1/4” spacer and bracket (short side) on protruding end of screw.
[ ] Position brackets as shown and secure in place firmly using lock washer and nut.
[ ] Insert 5/8” screws through angle brackets and place radial ring on top (B).
[ ] Secure radial ring in place with lock washers and nuts (2 places)
[ ] Install six 5/8” screws in open holes, secure with lock washers and nuts (C).

B

#8 nut

Radial Ring

5/8" x 8-32 (x2)

Small 90-deree Bracket

A

2-1/4" x 8-32

1/4" spacer

(x2)

#8 lockwasher

#8 nut

#8 split lockwasher

C

#8 nut

#8 lockwasher

5/8" x 8-32 (x6)

Figure-15: Feedline Connection

Base Tube

Figure-2: Ground Radial Ring Assembly

Step-3: Using the following items, assemble upper (80-meter) capacitive-hat support ring:

2
2
8
2
8
8

[ ] Locate two radial rings and place together so cupped grooves oppose.
[ ] Install two 5/8” screws from top side, as shown.
[ ] From bottom side, install a #10 spacer washer and support bracket on each screw.
[ ] Secure assembly using lock washers and nuts (finger-tighten only for now).
[ ] Install six 5/8” screws in remaining holes, secure with lock washers and nuts.
[ ] Set assembly aside for later installation.

Step-4: Using the following items, assemble lower (40-meter) capacitive hat radial clip.

2
1
2
2
2
2

[ ] Locate two radial clips and place together so cupped grooves oppose.
[ ] Insert two 5/8” screws from top side, as shown.
[ ] Install a spacer washer from bottom side on each screw.
[ ] Insert both screws down through the radial-clip bracket, as shown.
[ ] Secure bracket in place with lock washers and nuts (finger-tighten only).
[ ] Set assembly aside for later installation.

194174
196242
010009
360941
011941
010011

195393
196230
360941
010009
011941

5/8" x 8-32 (x2)

radial ring (x2)

#10 aluminum

washer (x2)

lockwasher (x2)

010011

nut (x2)

support bracket (x2)

8-hole radial ring
Upper radial-ring support bracket
5/8” x 8-32 screw
#10 aluminum spacer washer
#8 lock washer
#8 nut

Note: cups oppossing

lockwasher (x6)

nut (x6)

Figure-3: Assembly Detail, Upper Hat

Lower 4-radial clip
Lower radial clip support bracket
#10 aluminum spacer washer
5/8” x 8-32 screw
#8 lock washer
#8 nut

5/8" x 8-32 (x6)

Figure-12A: Connecting Radials to Base Radial Ring

Suggested Radial Pattern

65'

35'

65'

35'

35'

65'

35'

65'

Figure-12B: Recommended radial-wire layout

Restricted Space Pattern

33'

33'

33'

33'

33'

33'

33'

33'

33'

33'

Important Note: More than the prescribed number of radials may be installed on the MA8040V at your

option in order to optimize radiation efficiency. However, note that as radials are added, SWR may
eventually increase to an unacceptable level as driving resistance drops progressively further below 50
Ohms. Use the best compromise for your operating location.

Step-13: Install Resonator on Vertical Radiator

1
1

[ ] Slip the resonator tube inside the top of 1-1/8” radiator tube BE (Figure-13).
[ ] Position the contact lugs over the tubing mounting holes, as shown.
[ ] Using a 1-1/2” screw and 8-32 nut, secure resonator tube and coil wires in place. Tighten securely.

010123
010011

1-1/2” x 8-32 screw
#8 nut

spacer washer (2)

radial clip (2)

5/8" x 8-32 (2)

radial-clip support bracket

lockwasher (2)

nut (2)

Figure-4: Lower Radial Clip Assembly

Jumper wire

1-1/8" tube

1-1/2" x 8-32

Figure-13: Resonator Installation Detail

Step-5: Using the following items, install resonator loading coils.

bags of pre-mixed concrete are inexpensive and readily available at most major hardware outlets. Sink tube
a minimum of four feet and plumb with a level to ensure a straight vertical mount. When installation is
completed, use a hacksaw to remove damaged or un-needed exposed conduit. When sinking conduit in
concrete, do not allow tube to fill within 10” of top. If tube fills above this level, the antenna’s base assembly
cannot drop inside.

When installation

is complete,

cut pipe here

Driven

Mount

4-5 ft

minimum

1-1/2" ID

thin-wall

steel

conduit

Posthole

Mount

4 ft

captured in

concrete

Figure-11A: Suggested base supports.

MA8040V base tube may be set into 1-1/2” thin-wall conduit or clamped to side of post (Figure-10B).

Step-12: Install ground-radials

1
8

Notch support pipe
to prevent antenna
from rotating in base

096359
100449

Use standard TV

style tube-to-tube

splicing U-bolts

Figure-11B: Suggested mounting techniques

400’ spool of #18 enameled radial wire
Solder Lug

Installation Tips: When possible, bury wire 2-4 inches below surface. For lawns, split turf with edger, insert

wire, then press turf back together. For rocky or wooded terrain, cover with topsoil, tamp down, and add
ground-cover. Meander wire to skirt obstructions such as rocks and trees. If unable to extend ’65 radials, we
recommend cutting and installing twelve 33-foot radials as an alternative ground system.

[ ] Install the antenna base assembly on its mount (see Figure-12A).
[ ] Unroll, measure, and cut four 35-foot lengths of wire. Roll up and set aside.
[ ] Unroll, measure, and cut four 65-foot lengths of wire. Roll up and set aside.
[ ] At one end of each wire, remove enamel insulation and install a solder lug.
[ ] Connect radials to base-section radial ring, alternating long and short lengths.
[ ] Unroll and install each, creating the star pattern shown in Figure-12B.

1
1
1
4
4
8

[ ] On the insulator tube, identify the four coil-mount hole locations.
[ ] Install a 2” screw in each coil-mount hole and secure with a nut.
[ ] Install a spacer on each of the two 40-meter coil mounts at locations A, B.
[ ] Find the 40-meter coil and identify the end with screw and longer lead.
[ ] Orienting as shown at E, slide coil over tube and drop onto mounts. Secure with nuts.
[ ] Find 80-meter loading coil and identify end with longer lead (F).
[ ] Repeat the above procedure for the 80-meter coil at C, D.

126228
MA8040VCA2
MA8040VCA1
105630
010120
010011

24” Fiberglass resonator support tube
80-meter loading coil
40-meter loading coil
Loading coil standoff spacer
2” x 8-32 screw
#8 nut

C D

location

Drop 80-meter coil onto

mounting studs

F

long lead

lug

Insulator Tube

Drop 40-meter coil onto

mounting studs

lug

spacer

nut

nut

A B

40-meter coil 80-meter coil

location

2" x 8-32 screw

E

screw screw

lug

Figure-5: Loading Coil Mounting

Step-6: Using the following parts, install lower radial clip and jumper wire.

1
1
1
1
2

[ ] At A, use a 1-1/2” screw to install coil lug and 40-Meter radial-clip assembly, as shown.
[ ] Secure in place with a nut.
[ ] At B, install 1-1/4” screw through 80-Meter coil lead and insert through insulator tube.
[ ] On opposite side, install one end of jumper wire and secure with nut.
[ ] Position other end of jumper as shown at C. These leads will be attached to the antenna later on.

---------­MA8040VJ1
010040
010123
010011

To be attached

during final assembly

Radial clip assembly (as completed in Step-4)
80-meter resonator jumper wire
1-1/4” x 8-32 screw
1-1/2” x 8-32 screw
#8 nut

nut

1-1/2"

screw

jumper wire

C

A

radial clip

assembly

1-1/4"

screw

nut

B

Figure-6: Loading Section Assembly

Step-7: Using the following items, complete assembly of upper resonator.

Step-9: Using the following items, install 40-meter capacitive-hat rods.

1
1
1
1
1
3
1
1
1

[ ] Insert 1/2” tube (BF) into the 1/2” ID bushing and align screw holes (A).
[ ] Install the bushing and tube inside fiberglass resonator tube. Align all screw holes (B).
[ ] Slide 80-meter radial-ring assembly over outside of resonator tube, position with screw holes aligned (C).
[ ] Install 1-1/2” screw at (D) and capture coil-lead lug at bottom. Secure with nut and tighten firmly.
[ ] Find braid strap and nip eye off one end, as shown at (E).
[ ] Using existing hardware on radial ring, attach braid strap at (F) and secure in place.
[ ] Install small worm clamp on resonator tube and use to secure nipped end of braid.
[ ] Install small worm clamp on end of 1/2” tube BF, insert 3/8” tube BG and secure (G).
[ ] Install small worm clamp on end of 3/8” tube BG, insert 1/4” rod BH and secure (H).
[ ] Slip 1/4” vinyl tip cap on end of 1/4” rod BH at ( I ). Resonator will be set to length later on.

Step-8: Using the following items, assemble antenna radiator.

1
1
1
1
3

[ ] Place a worm clamp on one end of tube BC (72” x 1-3/8”).
[ ] Find 12” x 1-1/4” splice tube BB. Measure off 6” and mark.
[ ] Insert BB 6” inside BC, secure with worm clamp.
[ ] Place a worm clamp at far end of tube BC.
[ ] Find 72” x 1-1/4” tube BD and locate the un-slotted end. Measure off 6” and mark.
[ ] Insert BD 6” inside BC and secure with clamp.
[ ] Place a worm clamp on slotted end of BD.
[ ] Find 72” x 1-1/8” tube BE and locate the un-slotted end. Measure off 6” and mark.

---------­MA8040VBF
MA8040VBG
MA8040VBH
055105
030407
010123
902428
156336

80-M

coil

MA8040VBB
MA8040VBC
MA8040VBD
MA8040VBE
030412

80-meter radial ring assembly (as completed in Step-3)
1/2” OD x 24” resonator stub
3/8” OD x 24” resonator stub
1/4” OD x 24” resonator stub (solid rod)
1/4” vinyl end cap
Small worm clamp
1-1/2” x 8-32 screw
Braid strap
1/2” ID 80-meter resonator-stub bushing

1/2" ID bushing

C

D

align all

holes

B

worm clamp

F

Figure-7: Upper Resonator ( 80-meter) Assembly

Aluminum splice tube, 12” x 1-1/4”
Aluminum radiator section-2, 72” x 1-3/8” OD
Aluminum radiator section-3, 72” x 1-1/4” OD
Aluminum radiator section-4, 72” x 1-1/8” OD
Large Worm clamp

B

A

braid strap prep

insert and align

tube BF

E

cut

BF

G

BG

worm clamp

BH

H

vinyl cap

I

[ ] Insert BE 6” into BD and secure with clamp.

BB BC

splice

tube

6' x 1-3/8"

(insert 6")

17' 6"

6' x 1-1/4" 6' x 1-1/8"

BD BE

(insert 6") (insert 6")

Figure-8: Vertical Radiator Assembly

1
4
4

[ ] Loosen the 40-meter radial-clip hardware.
[ ] Install the four 25” rods, one in each clip opening. Tighten securely to capture all four rods.
[ ] Install a plastic end cap on each protruding rod end (lubricate with soap, as needed, to install).

---------­226442
056249

Pre-assembled resonator section (from Step-7)
Radial rod stock, 0.1” x 25”
Vinyl end caps

Install plastic tips (x4)

25" rod

25" rod

25" rod

25" rod

Figure-9: Installing 40-meter Radial Rods

Step-10: Using the following items, install 80-meter rods on resonator assembly.

8
8

[ ] Install a vinyl end cap on one end of each rod (lubricate with soap, as needed, to install).
[ ] Loosen radial-ring hardware and install rods, as shown in Figure-10.
[ ] Use maximum extension for best low-end tuning, minimum for best high-end tuning. Tighten hardware.

Step-11: Construct a base support.

Important Installation Site Safety Considerations:

226443
056249

1. No part of the antenna should contact overhead tree branches or foliage.

Radial-rod, 0.1” x 31”
Vinyl end cap

Maximum Rod Extension

Minimum Rod Extension

Figure-10: Inserting and adjusting radial rods

2. Antenna must be well clear of all power wires if accidentally toppled in any direction.

3. RF-energized surfaces must be inaccessible to accidental contact by people or pets.

4. RF exposure of humans in nearby occupied areas should not exceed FCC guidelines.

5. Other feedlines, masts, towers, etc. must be sufficiently far away to avoid detuning.

The MA8040V requires a stable base support (owner supplied). Any suitable support may be used, but the

Insert rods

antenna was especially designed to drop into 1-1/2” OD thin-wall steel galvanized conduit. This tubing may
be either driven into the ground or set into a posthole and captured in concrete (Figure-11A). Conduit and