Cushcraft X7 assembly instruction

ASSEMBLY &

INSTALLATION

20-15-10 Meter Seven Element Beam

COMMUNICATIONS ANTENNAS

951470 (8/98)

Thank you for your purchase of the Cushcraft X7 Tribander. This antenna is designed and manufactured to give
the best performance and trouble free service. The antenna will perform as specified if the instructions are followed
during assembly and installation. Cushcraft operates a full service Technical Support staff to answer questions
regarding assembly, tuning, parts and just about everything else. Please contact us by phone [phone]
(8 AM - 5PM Eastern Time), FAX [phone], or email [email protected] for prompt service.

WARNING

THIS ANTENNA IS AN ELECTRICAL CONDUCTOR. CONTACT WITH POWER LINES CAN RESULT IN DEATH OR SERIOUS INJURY. DO
NOT INSTALL THIS ANTENNA WHERE THERE IS ANY POSSIBILITY OF CONTACT WITH OR HIGH VOLTAGE ARC-OVER FROM POWER
CABLES OR SERVICE DROPS TO BUILDINGS. THE ANTENNA, SUPPORTING MAST AND/OR TOWER MUST NOT BE CLOSE TO ANY
POWER LINES DURING INSTALLATION, REMOVAL OR IN THE EVENT PART OF THE SYSTEM SHOULD ACCIDENTALLY F ALL. FOLLOW
THE GUIDELINES FOR ANTENNA INSTALLATION RECOMMENDED BY THE U.S. CONSUMER PRODUCT SAFETY COMMISSION AND
LISTED IN THE ENCLOSED PAMPHLETS.

Antenna System Planning

Before assembly, take time to review your installation plans for the antenna. Location of the antenna is very important. Surrounding objects such
as trees, power lines, buildings, and other antennas will interact with an HF Yagi. To minimize the effects of surrounding objects, mount the
antenna as high and in the clear as possible. Metallic guy wire within 30 feet of this antenna, if broken with strain insulators, will improve
performance.

40 Meter Add-On Kit

The X740 40 meter add-on kit is available for the X7. The kit consists of a loaded dipole element that is mounted on the boom section BA between
Elements #2 and #3. The 40 meter element requires a separate coax feed. Contact Cushcraft or your dealer for more information.

YOU MUST INSURE THAT NEITHER PEOPLE OR PETS CAN COME IN CONTACT WITH YOUR ANTENNA WHILE IT IS IN OPERATION.
DEADLY VOLTAGES AND CURRENTS MAY EXIST. ALSO, SINCE THE EFFECTS OF EXPOSURE TO RF ARE NOT FULLY UNDERSTOOD,
LONG TERM EXPOSURE TO INTENSE RF FIELDS IS NOT RECOMMENDED. THERE IS A WARNING STICKER WHICH MUST BE ATTACHED
TO THE BOOM AS SHOWN IN FIGURE 8A.

Plan your installation carefully. If you use volunteer helpers be sure that they are qualified to assist you. Make certain that everyone involved
understands that you are in charge and that they must follow your instructions. If you have any doubts at all, employ a professional antenna
installation company to install your antenna.

System Grounding

Direct grounding of the antenna, mast and tower is very important. This serves as protection from lightning strikes and static buildup. A good
electrical connection should be made to one or more ground rods directly at the base of the tower or mast using at least #10 AWG ground wire
and non-corrosive hardware. For details and safety standards, consult the National Electrical Code. A coaxial lightning arrester should be used.
Cushcraft offers several different models such as the LAC series.

Assembly

The assembly procedure for the X7 consists of assembling the following subassemblies.

1) Verification of Parts. 2) Boom Assembly. 3) Element Assembly. 4) Element to Boom Assembly.

5) Feed System Assembly. 6) Boom to Mast Clamp Assembly.

Assembly of the X7 will be easiest if the preceding steps are performed in the given order. For easier tower mounting, some or all of the elements
may be mounted to the boom when the antenna is on the tower. If this option is chosen, the feed system can be attached after the elements
are mounted.

Please read through the entire assembly procedure before beginning.

1-Verification of Parts

Verify all parts are present by using the X7 Master Parts List. Check off each part when it is counted. There are extra parts intentionally shipped
with this antenna. Place common hardware in temporary containers for ease of assembly. Note all hardware is Stainless Steel.

Part No. Description Metric Equivalent Quantity

014597 #8-32 x 2-3/4" Stainless Steel Machine Screw . . . . . . . . . . . . . . . . . . . . #8 x 7.0 cm 2 ____

X79FS 1/2" Tinned Copper Braid 6" Long with Lugs . . . . . . . . . . . . . . . . . . . 1.2 cm x 15 cm 2 ____

010011 #8-32 Stainless Steel Nut . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 ____

010082 1/4-20 x 1"Hex Bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.6 cm - 20 x 2.5 cm 48 ____

010085 1/4-20 Stainless Steel Nut . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.6 cm 15 ____

010120 #8-32 x 2" Stainless Steel Machine Screw . . . . . . . . . . . . . . . . . . . . . . . #8 x 5.1 cm 4 ____

010123 #8-32 x 1 1/2" Stainless Steel Machine Screw . . . . . . . . . . . . . . . . . . . . #8 x 3.8 cm 4 ____

010084 1/4" Stainless Steel Flat Washer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.6 cm 87 ____

010207 3/8" Stainless Steel Flat Washer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.9 cm 4 ____

010208 3/8" Stainless Steel Lock Washer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.9 cm 4 ____

1

Verification of Parts continued

Part No. Description Metric Equivalent Quantity

010209 3/8" Stainless Steel Nut . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.9 cm 4 ____

011941 #8 Stainless Steel Lock Washer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 ____

013209 2-7/8" Center-to-center U-Bolt 4" Long . . . . . . . . . . . . . . . . . . 7.3 cm -10.2 cm Long 2 ____

014387 #8-32 Stainless Steel Lock Nut . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 ____

014399 1/4” Stainless Steel Lock Nut . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.6 cm 85 ____

014495 7/8" Cush-a-Clamp® . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2 cm 4 ____

014496 1" Cush-a-Clamp® . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.5 cm 4 ____

014497 1-1/4" Cush-a-Clamp® . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.2 cm 6 ____

014588 1/4" x 4" Stainless Steel Hex Bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.6 x 10.2 cm 11 ____

014592 1/4" Stainless Steel Flat Washer 1/8" Thick . . . . . . . . . . . . . . . . . . . . . . 0.6 x 0.3 cm 14 ____

030407 5/8" Worm Clamp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.6 cm 12 ____

030409 11/16" Worm Clamp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.7 cm 14 ____

030410 1" Worm Clamp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.5 cm 16 ____

030411 1-1/8" Worm Clamp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.9 cm 6 ____

030412 1-1/2" Worm Clamp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.8 cm 6 ____

050053 1/2" Black Plastic Cap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.3 cm 2 ____

050077 3/8" Black Plastic Cap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.9 cm 12 ____

054526 2-1/2" Black Plastic Cap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6.4 cm 2 ____

124565 5/8" x 8" Drilled Fiberglass Insulator . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.6 x 20.3 cm 2 ____

124566 7/8" x 8" Drilled Fiberglass Insulator . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2 x 20.3 cm 1 ____

124567 1" x 8" Drilled Fiberglass Insulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.5 x 20.3 cm 1 ____

154554 3” x 2-1/2” x 1” Tuning Tube Insulator . . . . . . . . . . . . . . . . . . . . . 7.6 x 6.3 x 2.5 cm 1 ____

170035 2-1/2" Formed Aluminum Vee Blocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.4 cm 2 ____

194542 8" x 8" x 1/4" Aluminum Mounting Plate . . . . . . . . . . . . . . . . . . 20.3 x 20.3 x 0.6 cm 1 ____

194555 2-7/8” x 1” x 1/4” Tuning Tube Shorting Strap . . . . . . . . . . . . . . . . . 7.3 x 2.5 x .6 cm 1 ____

244604 NOALOX® conductive lubricant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 ____

290326 Danger Label . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 ____

323832 2” x 1-1/2” x 1/8” Feed Strap Plastic Insulator . . . . . . . . . . . . . . . 5.1 x 3.8 x 0.3 cm 3 ____

324504 3" x 5-1/4" x 1/8" Drilled Extruded Aluminum Bracket . . . . . . . . . 7.6 x 13.3 x 0.3 cm 6 ____

324506 8" x 5-1/4" x 3/16" Drilled Extruded Aluminum Bracket . . . . . . . 20.3 x 13.3 x 0.5 cm 2 ____

324509 4" x 5-1/4" x 3/16" Drilled Extruded Aluminum Bracket . . . . . . . 10.2 x 13.3 x 0.5 cm 8 ____

324564 1" x 5-1/4" x 1/8" Drilled Extruded Aluminum Bracket . . . . . . . . . 2.5 x 13.3 x 0.3 cm 2 ____

330885 Brush . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 ____

T6 15 Meter Director Trap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 ____

T9 10 Meter Director Trap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 ____

MNX79 MNX7 Matching Network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 ____

BA 2-1/2" x 84" Drilled Aluminum Tube . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.4 x 213 cm 1 ____

BB 2-3/8" x 24" Drilled Aluminum Tube . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.0 x 61 cm 1 ____

BC 2-1/2" x 60" Drilled Aluminum Tube . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.4 x 152 cm 1 ____

BD 2-3/8" x 12" Drilled Aluminium Tube . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.0 x 31 cm 1 ____

BE 2-1/2" x 72" Drilled Aluminum Tube . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.4 x 183 cm 1 ____

EA 1-1/4" x 72" Aluminum Tube slotted 2 ends . . . . . . . . . . . . . . . . . . . . . . 3.2 x 183 cm 1 ____

EB 1-1/8" x 52 " Aluminum Tube slotted 1 end, 1" tube insert 1 end . . . . . 2.8 x 132 cm 4 ____

EC 1" x 36" Aluminum Tube slotted 7/8" swege 1 end . . . . . . . . . . . . . . . . . . 2.5 x 91 cm 4 ____

ED 3/4" x 36" Aluminum Tube slotted 5/8" swege 1 end . . . . . . . . . . . . . . . . 1.9 x 91 cm 8 ____

EE 1/2" x 36" Aluminum Tube slotted 1 end . . . . . . . . . . . . . . . . . . . . . . . . . 1.3 x 91 cm 6 ____

EF 3/8" x 48" Aluminum Tube . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.0 x 122 cm 4 ____

EG 1" x 48" Aluminum Tube slotted 2 ends . . . . . . . . . . . . . . . . . . . . . . . . . 2.5 x 122 cm 1 ____

EH 7/8" x 48" Aluminum Tube slotted 1 end . . . . . . . . . . . . . . . . . . . . . . . . 2.2 x 122 cm 2 ____

EJ 3/8" x 32" Aluminum Tube . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.0 x 81 cm 4 ____

EK 1" x 24" Aluminum Tube slotted 1 end, drilled 1 end . . . . . . . . . . . . . . . 2.5 x 61 cm 2 ____

EL 1-1/4" x 36" Aluminum Tube, slotted 1 end, drilled 1 end . . . . . . . . . . . . 3.2 x 91 cm 2 ____

EM 1/2" x 24" Aluminum Tube slotted 1 end . . . . . . . . . . . . . . . . . . . . . . . . . 1.3 x 61 cm 6 ____

EN 3/8" x 36" Aluminum Tube . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.0 x 91 cm 4 ____

EP 1-1/4" x 48" Aluminum Tube slotted 2 ends . . . . . . . . . . . . . . . . . . . . . . 3.2 x 122 cm 1 ____

ER 1-1/8" x 48" Aluminum Tube slotted 1 end . . . . . . . . . . . . . . . . . . . . . . . 2.9 x 122 cm 2 ____

ES 1/2" x 36" Aluminum Tube . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.3 x 91 cm 2 ____

ET 7/8" x 36" Aluminum Tube slotted 1 end . . . . . . . . . . . . . . . . . . . . . . . . . 2.2 x 91 cm 2 ____

EU 3/4" x 36" Aluminum Tube slotted 5/8" OD swege 1 end, drilled 1 end . . 1.9 x 91 cm 4 ____

EV 1"x 36" Aluminum Tube slotted 1 end . . . . . . . . . . . . . . . . . . . . . . . . . . 2.5 x 91 cm 2 ____

EY 1" x 5-1/4" Aluminum Tube slotted 2 ends . . . . . . . . . . . . . . . . . . . . . . 2.5 x 13.3 cm 2 ____

EZ 3/8" x 30" Intentionally Bent Aluminum Tube crimped and drilled 1 end . .1.0 x 76 cm 2 ____

FL1 5/8" x 16" Aluminum Flat Feedline Strap . . . . . . . . . . . . . . . . . . . . . . . 1.6 x 41 cm 2 ____

FL2 5/8" x 20-3/4" Aluminum Flat Feedline Strap . . . . . . . . . . . . . . . . . . . . . . 1.6 x 53 cm 2 ____

FL3 5/8" x 28-3/4" Aluminum Flat Feedline Strap . . . . . . . . . . . . . . . . . . . . . . 1.6 x 73 cm 2 ____

Figure 1

84”

26

BA

3-3/4”

(9.52 cm)

(213.4 cm)

1-1/4”

(3.17 cm)

(61.0 cm)

4-3/4”

(29.8 cm)

24”

16-3/4”

(42.5 cm)

BB

11-3/4”

(29.8 cm)

4”

(10.2 cm)

60”

(152.4 cm)

BC

(30.5 cm)

4-3/4”

(29.8 cm)

12”

BD BE

4-3/4”

(29.8 cm)

(3.2 cm)

1-1/4”

72”

(182.9 cm)

3-3/4”

(9.52 cm)

26

Figure 2

18’

(5.5 m)

BA

BB

BC

BD

BE

Figure 3

BC

See

Fig. 4C

See Figure 4A

Element #6

See

Fig. 4C

Fig. 4A

See

BE

See

Fig. 4B

See

Fig. 4B

53”

(134.6 cm)

See

Fig. 4C

BA

Mounting hole

for optional 40M

See Figure 4A

Element #3

Figure 4

add-on kit.

See

Fig. 4A

Element#1Element

#2

Tuning Tube

Support

Element

#3

Element#4Element#5Element

Insulator

NOTE: The X7 is shipped with NOALOX® conductive lubricant and an applicator brush. Apply small amounts
of the lubricant to telescoping tubing sections during element and boom assembly. Apply small amounts of
lubricant to bolt/U-bolt threads to prevent galling (seizing) of the nuts during assembly. Also, apply small
amounts to the feedstrap assembly and matching network connections.

2-Boom Assembly

Figures 1, 2, 3 and 4 show the steps for boom assembly. Identify the tubing
sections, element brackets and hardware required for this step by using the
Boom Subassembly Parts List. Note the element brackets for Elements #3 and
#6 join the boom sections (Figure 3).

Refer to Figures 4A, 4B, 4C and 4D to assemble element brackets. The
1/4” hex nuts (85) are used as spacers on all brackets. Tighten these nuts in
place before assembling element bracket halves. The Boom may be placed on
a flat surface with all brackets laying flat on the surface. This will allow all brackets
to be fastened in line with each other. When tightening the hardware, refer to
Figure 4A and tighten all bracket hardware in this order. Do not tighten the bolts
on the Tuning Tube Support Insulator Bracket (Figure 4D). Allow the bracket to
remain loose on the boom for Step 5 (Feed System Assembly).

Nylon insert lock nuts are designed for one-time use. Do not tighten these
nuts if you expect to disassemble antenna sections during antenna mounting.

After mounting boom end caps (26), drill a small hole (1/4”) in the bottom
edge of the cap for water drainage. Determine which edge of the end cap will
be on the ground facing side of the boom when antenna is mounted in its final
position.

#6

ID Part # Description Dimensions Qty

82 010082 Hex 1/4-20 x 1” 30

84 010084 SS Lock 1/4” 39

85 010085 SS Nut 1/4-20 15

99 014399 SS Lock 1/4” 39

504 324504 Aluminum 3” x 5-1/4” x 1/8” 6

509 324509 Aluminum 4” x 5-1/4 x 3/16” 8

564 324564 Aluminum 1” x 5-1/4” x 1/8” 2

588 014588 SS Hex 1/4” x 3-1/2” 9

592 014592 SS Flat 1/4” (1/8” thick) 14

Bolt (.6 x 2.5 cm)

Washer (.6 cm)

(.6 cm)

Nut (.6 cm)

Bracket (7.6 x 13.3 x .3 cm)

Bracket (10.2 x 13.3 x .5 cm)

Bracket (2.5 x 13.3 x .3 cm)

Bolt (.6 x 10.2 cm)

Washer (.6 x .3 cm)

Element

#7

Leave 1/8” gap between brackets

82

84

82

84

82

84

82

84

509

85

Figure 4A

592

85

588

84

588

84

509

99

99

509

Tighten
LAST

99

99

Tighten
SECOND

99

Tighten
FIRST

99

Leave 1/8” gap between brackets

99

99

99

99

99

509

99

99

99

99

99

504

82

84

82

84

82

84

509

82

84

82

84

82

84

82

84

504

85

85

Figure 4B

592

85

592

85

588

84

509

Figure 4C

84

588

504

82

84

564

82

84

85

Figure 4D

564

99

Leave loose
for Step 5.

99

4”

(10.16 cm)

1/4”

(.63 cm)

ER

EP

ER

Butt ends of ER’s together

at the center of EP

24”(61cm)

3-Element Assembly

Figures 5, 5A, 5B, and 5C show the steps for element assembly. Identify the tubing sections required for each element
using the Element Subassembly Parts List.
Each telescoping tubing section is inserted 4 inches into the larger section except where noted in Figure 5. Adjust the
length of the end tubing section to give each element the proper total half length. All dimensions should be within 1/4 inch
of the values given. Mar k the center of tubing sections EA, EG, and EP with a marker as shown in Figure 6A. These
marks will be used in Step 4 when elements are mounted on the boom. The dimension for tube ES is measured from
the end of trap TB. The dimension between traps TB and T9 is measured between the ends of each trap. The 77 inch
dimension from element #7 center is measured to the end of trap T9. Insure all traps are installed with arrows pointing
toward the boom. Also position trap drain holes so they will be facing the ground when the antenna is in its final position.

Element #1

EF

77

Element #3

77

EN

FIGURE 5

Element #7

407

Final Length

Adjustment

Element #2

407 409

EE

Final Length

Adjustment

Element #4

53

(73.7 CM)

Figure 5A

EE

ES

29”

11

941

120

77

409

409

EJ

ED

77

T6

567

ED

407

Final Length

Adjustment

410

407

EN

Final Length

Adjustment

Element #5

410 410

EY

T9

7”

(17.8 CM)

11
941

120

410

EM

EC

EM

Element #6

EC

409

409

77

410

411

EB

410

ED

411

EB

410

ED

EF EE

Final Length

Adjustment

77

EV

8” (20.3 CM)

407

EJ

Final Length

Adjustment

411 412

Insert

Figure 5B

5

220”

(558.8 CM)

EH

147-1/2”

(374.6 CM)

205-1/2”

(522 CM)

ET

140”

(355.6 CM)

409

111”

(281.9 CM)

407 409

EM

83”

(210.8 CM)

ER

75”

(190.5 CM)

11

941

120

412

IMPORTANT

Unless indicated otherwise, telescope
elements 4” (10.16 cm) and tighten
the worm clamp.

C

11
941

120

EA

EP

EG

C

L

567

566

565

565

24”

(60 CM)

L

412

410

EL

410

EK

EU

EU

566

410

See Fig. 5A

EL

See Fig. 5B

EK

See Fig. 5C

EU

See Fig. 5C

EU

412

412

220”

(558.8 CM)

EH

147-1/2”

(374.6 CM)

412

205-1/2”

(522 CM)

(355.6 CM)

409

(281.9 CM)

409

EM

83”

(210.8 CM)

ER

(190.5 CM)

ET

140”

111”

75”

Install all worm clamps as shown. Tighten all worm clamps until the telescoped tubing cannot rotate
inside the larger tube. Take care not to ov ertighten and strip the worm clamp. Extra w orm clamps are provided.
Note that all element sections can be fastened using a self-taping screw at each tubing transition. Use
stainless screws for best performance. Properly installed wor m clamps will provide years of trouble free
service.
The X7 is constructed entirely with .058-inch wall tubing. This creates a tight transition with the closest
possible fit and better ice-loading characteristics than antennas constructed with thinner wall tubing.
Elements 3, 4, 5 and 6 have fiberglass center sections. Reference figures 5A, 5B and 5C for proper assembly .

After mounting element end caps (53, 77) punch a small hole (1/4”) in the bottom edge (ground facing side)
of the cap for water drainage.

EB

EB

407

407

Final Length

Adjustment

410

ED

410

Final Length

Adjustment

77

EJ

411

8” (20.3 CM)

Insert

Figure 5C

ED

EFEE

EV

411

411

EC

409

EC

409410

Final Length

Adjustment

77

410

410

EM

Final Length

Adjustment

407

EM

410

(17.8 CM)

11

941

123

EY

7”

407

565

ED

410

410

EN

407409

EJ

ED

EE

Final Length

Adjustment

77

409

EE

Final Length

Adjustment

EF

407

EN

77

409

ES

T6T9

11

941

123

53

29”

(73.7 CM)

77

77

ID Part # Description Dimensions Qty

11 010011 SS Nut #8-32 8

53 050053 Black 1/2” 2

77 050077 Black 3/8’ 12

120 010120 SS Machine #8-32 x 2” 4

123 010123 SS Machine #8-32 x 1-1/2” 4

407 030407 Worm 5/8” 12

409 030409 Worm 11/16” 14

410 030410 Worm 1” 18

411 030411 Worm 1-1/8” 6

412 030412 Worm 1-1/2” 6

565 124565 Fiberglass 5/8” x8” 2

566 124566 Fiberglass 7/8” x 8” 1

567 124567 Fiberglass 1” x 8” 1

941 011941 SS Lock #8 8

EA X79EA Aluminum 1-1/4” x 72” 1

EB X79EB Aluminum 1-5/8” x 52” 4

EC E79EC Aluminum 1” x 36” 4

ED X79ED Aluminum 3/4” x 36” 8

EE X79EE Aluminum 1/2” x 36” 6

EF E79EF Aluminum 3/8” x 48” 4

EG E79EG Aluminum 1” x 48” 1

EH E79EH Aluminum 7/8” x 48” 2

EJ E79EJ Aluminum 3/8” x 32” 4

EK X79EK Aluminum 1” x 24” 2

EL X79EL Aluminum 1-1/4” x 36” 2

EM X79EM Aluminum 1/2” x 24” 6

EN X79EN Aluminum 3/8” x 36” 4

EP X79EP Aluminum 1-1/4” x 48” 1

ER X79ER Aluminum 1-1/8” x 48” 2

ES X79ES Aluminum 1/2” x 36” 2

ET X79ET Aluminum 7/8” x 36” 2

EU X79EU Aluminum 3/4” x 36” 4

EV X79EV Aluminum 1” x 36” 2

EY A34SEF Aluminim 1” x 5-1/4” 2

T6 T6 15 M 2

T9 T9 10 M 2

T6

T9

Plastic Cap (1.3 cm)

Plastic Cap (0.9 cm)

Screw #8 x 5.1 cm)

Screw (#8 x 3.8 cm)

Clamp (1.6 cm)

Clamp (1.7 cm)

Clamp (2.5 cm)

Clamp (2.9 cm)

Clamp (3.8 cm)

Insulator (1.6 x 20.3 cm)

Insulator (2.2. x 20.3 cm)

Insulator (2.5 x 20.3)

Washer

Tube (3.2 x 183 cm)

Tube (2.8 x 132 cm)

Tube 2.5 x 91 cm)

Tube (1.9 x 91 cm)

Tube (1.3 x 91 cm)

Tube (1.0 x 122 cm)

Tube (2.5 x 122 cm)

Tube (2.2 x 122 cm)

Tube (1.0 x 81 cm)

Tube (2.5 x 61 cm)

Tube (3.2 x 91 cm)

Tube (1.3 x 61 cm)

Tube (1.0 x 99 cm)

Tube (3.2 x 122 cm)

Tube (2.9 x 122 cm)

Tube (1.3 x 91 cm)

Tube (2.2 x 91 cm)

Tube (1.9 x 91 cm)

Tube (2.5 x 91 cm)

Tube (2.5 x 13.3 cm)

Trap

Trap

6

See

Fig. 6D

See

Fig. 6E

Figure 6

See

Fig. 6B

See

Fig. 6E

See

Fig. 6F

See

Fig. 6C

See

Fig. 6D

Element#1Element

#2

Mark Center Line

element half lengths.

99

84

497

Tuning Tube

of element using

84

Support

Insulator

99

Element

#3

Figure 6A

Figure 6B

99

84

497

1-1/4” Cush-A-Clamp

Element#4Element#5Element

#6

Figure 6D

99
84

497

Figure 6E

99

84

496

Element

#7

99

84

99

84

99

84

497

1-1/4” Cush-A-Clamp

99

84

496

1” Cush-A-Clamp

Figure 6F

495

99

84

99

84

Figure 6C

99

84

495

7/8” Cush-A-Clamp

4-Element to Boom Assembly

Elements can be attached to the boom when the antenna is on the ground or when
the antenna is being installed on a tower. Identify the hardware required to secure
the elements by using the Element-to-Boom Parts List. Figure 6 shows the position
of each element on the boom. Figures 6A, 6B, 6C, 6D, 6E, 6F show the hardware
required to attach each element to the element bracket Position each element
center mark equidistant between each Cush-A-Clamp. Leave the Cush-A-Clamps
loose on the Log Cell Elements (#3, #4, #5, #6) until the feed straps are attached
in Step 5. There are three sizes of Cush-A-Clamps. Tighten each clamp until the
element tubing can no longer rotate inside the Cush-A-Clamp. The lock washers
under the nuts securing the Cush-A-Clamps should be tightened until they are flat
against the mounting bracket.

99

99

84

495

ID Part # Description Dimensions Qty

84 010084 SS Lock 1/4” 28

99 014399 SS Lock 1/4” 28

495 014495 Cush-a-Clamp® 7/8” 4

496 014496 Cush-a-Clamp® 1” 4

497 014497 Cush-a-Clamp® 1-1/4” 6

84

Washer (.6 cm)

Nut (.6 cm)

99

84

495

7/8” Cush-A-Clamp

(2.2 cm)

(2.5 cm)

(3.2 cm)

7

Element

87

87

832

9EZ

#3

Mast mounting

location for reference

Element

#4

Element

#5

Element

#6

554

EZ

1/2”

(1.3 cm)

555

832

FL3

FL2

832

FL1

832

Figure 7

5-Feed System Assembly

The feed system consists of 3 sub-assemblies. They are the feed-straps,
the tuning-tube insulator and the matching network. Figure 7 illustrates the
3 pairs of feed-straps (FL1, FL2, FL3). Refer to the Feed System Subassembly
Parts List for the hardware required to install the straps. Slide a feed-strap
insulator (832) on to each pair of feed-straps to space and insulate the straps.
Elements may be rotated slightly during feed strap attachment. Tighten Cush­A-Clamps on Elements #3, #4, #5 and #6.

Locate the 2 tuning-tubes (EZ). Attach the punched ends of each tube to
the screws at the center of Element #3.

Locate the Tuning Tube Shorting Strap (555). Loosen the 2 screws and
slide the strap onto the tuning tubes (EZ). Leave strap loose.

ID Part # Description Dimensions Qty

87 014387 SS Lock #8-32 8

554 154554 Tuning Tube 3” x 2-1/2” x 1” 1

555 194555 Tuning Tube 2-7/8” x 1” x 1/4” 1

832 323832 Strap 2” x 1-1/2” x1/8” 3

FL1 X79FL1 Feedline 5/8” x 16” 2

FL2 X79FL2 Feedline 5/8” x 20-3/4” 2

FL3 X79FL3 Feedline 5/8” x 28-3/4” 2

EZ X79EZ Bent Alum 3/8” x 30” 2

Nut

Insulator (7.6 x 6.3 x 2.5 cm)

Shorting Strap (7.3 x 2.5 x .6 cm)

Insulator (5.1 x 3.8 x .3 cm)

Strap (1.6 x 41 c m)

Strap (1.6 x 53)

Strap (1.6 x 73 cm)

Tube (.9 x 7.6 cm)

Figure 7B

Figure 7A

82

84

554

82

84

ID Part # Description Dimensions Qty

82 010082 Hex 1/4-20 x 1” 2

84 010084 SS Lock 1/4” 2

87 014387 SS Lock #8-32 2

554 154554 Tuning Tube 3” x 2-1/2” x 1” 1

555 194555 Tuning Tube 2” x 1-1/2” x 1/8” 1

597 014597 SS Machine #8-32 x 2-3/4” 2

941 011941 SS Lock #8 4

EZ Tuning Tube 3/8” x 30” 2

FS X79FS Feed 6” 2

MN MNX79 Matching 1

Bolt (.6-20 x 2.5 cm)

Washer (.6 cm)

Nut

Insulator (7.6 x 6.3 x 2.5 cm)

Shorting Strap (5.1 x 3.8 x .3 cm)

Screw (7.0 cm)

Washer

(,95 x 76.2 cm)

(15.2 cm)

Network

EZ

555

Refer to Figure 7A and attach the tuning tube insulator to the
boom bracket. Use the hardware listed in the Tuning Tube Insulator
Subassembly Parts List. Slide the insulator toward tuning tubes (EZ)
until tube ends slide into the insulator holes, (Figure 7B). Tighten
bolts on boom bracket securing tuning tube insulator in place.

Reference Figure 7 and position the Tuning Tube Shorting Strap
(555) 1/2 inch from the tuning tube insulator. Adjusting this strap will
not have a significant effect on the VSWR of the X7. Tighten strap
screws.

Reference Figure 7C for matching network mounting. Required
hardware is listed in the Matching Network Subassembly Parts List.
Attach matching network (MN) to boom with two 8-32 bolts (597).
Connect feed straps (FS) from matching network terminals to each
FL3 end at the center of Element #6. Form drip loops in the feed
straps and position them as shown in Figure 7C. Form the feed­straps away from the Cush-A-Clamp U-bolts and Element #6 element
bracket.

597

87

Coax Drip Loop

941

941

FS

MN

Form Drip Loops
with feed straps.

Figure 7C

597

87

941

87

87

Element #6

87

9

FL3

3209

3209

35

84

82

Figure 8

542

99

207

207

208

208

209

209

208

207

Boom Shelf

209

209

208

207

35

506

326

84

99

Figure 8A

588

82

84

99

588

99

84

506

506

ID Part # Description Dimensions Qty

35 170035 Aluminum 2-1/2” 2

82 010082 Hex 1/4-20 x 1” 16

84 010084 SS Lock 1/4” 18

99 014399 SS Lock 1/4” 18

207 010207 SS Flat 3/8” 4

208 010208 SS Lock 3/8” 4

209 010209 SS 3/8” 4

326 290326 Danger 1

506 324506 Aluminum 8” x 5-1/4” x 3/16” 2

542 194542 Alu Mounting 8” x 8” x 1/4” 1

588 014588 SS Hex 1/4” x 3-1/2” 2

3209 013209 U-Bolt 2-7/8” 2

V-Block (6.3 cm)

Bolt (2.5 cm)

Washer (0.6 cm)

Nut (.6 cm)

Washer (.95 cm)

Washer (.95 cm)

Nut (.95 cm)

Label

Bracket (20.3 x 13.3 x .5 cm)

Plate 20.3 x 20.3 x .6 cm)

Bolt (.6 x 8.9 cm)

(7.3 cm)

6-Boom to Mast Clamp Assembly

The X7 boom to mast clamp is designed to be mounted on the
tower/mast so the built in boom shelf feature can be utilized. Following this
suggestion, if possible, will simplify antenna installation.

Reference Figure 8 for assembly of boom to mast clamp. Required
hardware is listed in the Boom to Mast Clamp Assembly Parts List. Form
the boom shelf by attaching the lower boom bracket (506) to the mast plate
(542). Attach mast plate (542) to mast using U-bolts (3209) and V-blocks
(35).

Place the boom on the boom shelf during installation. Loosely
attach the top boom bracket (506) to the mast-plate (542) and to the lower
boom bracket (506) as shown in Figure 8A. This allows the boom to be
moved back and forth for tower top element mounting.

When all elements are securely mounted to the boom and the
feed system is in place, line up the 2 holes in the top of the upper boom
bracket (506) holes with the corresponding 2 holes in boom section BC.
Insert bolts (588) and tighten in place. Next, tighten the 8 bolts, securing
the upper and lower boom brackets. Tighten the 4 bolts connecting the
upper boom bracket to the mast plate.

Attach good quality coax with a PL-259 connector to the X7
matching network. Route the coax as shown in Figure 7C. Form a drip-loop
with the coax and secure the coax to the boom. Insure PL-259 connector
is waterproofed with a good quality sealant after it is attached to the matching
network.

Tuning Procedure

The X7 does not require tuning. The broadband VSWR characteristics of the log cell can not be improved by adjusting element lengths. Varying the
element dimensions from those suggested in this manual is not recommended. For help with tuning, please contact Cushcraft technical support.

The X7 Design Story

Cushcraft marketed its first 10-15-20 meter tri-bander, the ATB-34, in 1976. The antenna was updated mechanically and re-introduced

as the A4 in 1980. The A4 evolved into the A4S when all hardware was changed to stainless steel.

The ATB-34, A4, A4S models became the most popular 18-foot tri-bander worldwide. In 1997 the A4S was evaluated for performance
using the latest antenna design software. Computer analysis showed potential improvements were possible through the use of a log periodic
cell for a driven element. The X7 was born. The log periodic cell feed is the only commercially available feed system with inherent forward
gain over a dipole. By properly spacing the reflectors and directors, and input impedance of 200 ohms was achieved on 10, 15, and 20
meters. A 4:1 quadrifilar Guanella type ferrite balun was designed to provide a 50 ohm match at the X7 feedpoint.

The mechanical construction of the X7 was designed using Y agi Strength® (YS) software. A safety factor of 1.25 was used to guarantee
an added cushion of safety over the 100 MPH rating of the boom, elements and hardware. All tubing for the boom and elements is 0.058
inch wall. The element and boom brackets are constructed of 6061-T6 extruded aluminum. All hardware is stainless steel.

On-the-air performance of the X7 yields an excellent radiation pattern, broadband low VSWR, and minimal trap loss.

Cushcraft has developed new manufacturing equipment to improve the quality of our products. Our products are now designed and
constructed to a higher level of quality than ever before. We hope you will appreciate our efforts.

SPECIFICATIONS

Frequency Coverage (Meters) 10, 15, 20
Total number of Elements 7
Maximum Gain (dB) 20M 12.5 @ 14 deg

@ One Wavelength 15M 13.0 @ 12 deg

above ground 10M 12.9 @ 14 deg
Maximum Front to Back Ratio (dB) 30
Number of Elements per Band 3
VSWR Minimum 1.1:1
VSWR 1.5:1 Bandwidth (KHz) 20M 600

Longest Element, ft (m) 37.2 (11.33)
Turning Radius, ft (m) 20.0 (6.09)
Boom Length, ft (m) 18 (5.49)
Boom Diameter, in (cm) 2-1/2 (6.35)
Maximum Mast Diameter OD, in (cm) 2-1/2 (6.35)
Maximum Wind Survival, mph (kph) >100 (>161)
Maximum Wind Surface Area, ft
Windload @ 80 mph, lb (kg) 202 (92)
Maximum Power Handling (KW) 2
Weight, lb. (kg) 60 (27.2)
Design Safety Factor 1.25

15M 750
10M 1700

2

(m2) 7.9 (.73)

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 judgement of Cushcraft, any such antenna is defective, then Cushcraft will, at its option,
repair or replace the antenna 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. Any 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 a limitation on how long
an implied warranty lasts or exclusions or limitations of incidental or consequential damages, so the above limitation and exclusion 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 USA • Telephone: [phone] • Fax: [phone] • E-mail: [email protected]

Web Site: http://www.cushcraft.com • International - Tel: [phone] • Fax:[phone]

Limited Warranty

COMMUNICATIONS ANTENNAS