Cushcraft X740 Instructions

ASSEMBLY &

INSTALLATION

X740

40 Meter ADD-ON KIT FOR X7

COMMUNICATIONS ANTENNAS

951473 (5/98)

X740

Thank you for your purchase of the Cushcraft X740 40 meter add-on kit. This kit 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 or voice mail after hours), FAX [phone], or email [e-mail].

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 INSTALLA TION 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.

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 A

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 X740 consists of assembling the following subassemblies. 1) Verification of Parts. 2) Element Assembly

3) Element to Boom Assembly. 4 )Feed System Assembly. 5) Element Truss Assembly. 6) X-hat Assembly Assembly of the X740 will

be easiest if the preceding steps are performed in the given order.

YOU MUST INSURE THAT NEITHER PEOPLE OR PETS CAN COME IN CONTACT WITH YOUR ANTENNA WHILE IT IS IN

. Plan your installation carefully. If you use volunteer helpers be sure that

Please read through the entire assembly procedure before beginning.

1-Verification of Parts

Verify all parts are present by using the X740 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 Equiv Quantity
010011 #8-32 SS Nut 2
010082 1/4-20 x 1" SS Hex Bolt 2.5 cm 9
010084 1/4" SS Lock Washer 0.6 cm 24
010085 1/4-20 SS Nut 0.6 cm 2
010104 1/4" SS Flat Washer 0.6 cm 2
010207 3/8" SS Flat Washer 0.9 cm 2
010212 1/4-20 x 2" SS Hex Bolt 5.1 cm 2
010231 #8-32 x 1-3/4" SS Machine Screw 38 x 4.4 cm 6
010232 #8-32 x 2-1/2" SS Machine Screw 6.4 cm 1
011941 #8 SS Lock Washer 11
014387 #8-32 SS/Nylon Hex Lock Nut 9
014399 1/4-20 SS/Nylon Hex Lock Nut 0.6 cm 24
014497 1 1/4" Cush-a-Clamp 3.2 cm 6
014588 1/4" x 3 1/2" SS Hex Bolt 0.6 cm x 8.9 cm 1
014592 1/4" Flat Washer 1/8" thick 0.6 cm x 0.3 cm 2
024259 1/8" Thimble 0.3 cm 2
024624 1/8" Cable Clamp 0.3 cm 6
030407 5/8" Worm Clamp 1.6 cm 2
030409 1-1/16" Worm Clamp 1.7 cm 2
030411 1-1/8" Worm Clamp 2.9 cm 4
030412 1-1/2" Worm Clamp 3.8 cm 2
032881 2-3/4" Worm Clamp 7 cm 2
050077 3/8" Plastic Cap 1 cm 2
050131 1-1/8" Plastic Cap 2.9 cm 1
094622 30' Roll of Phillystran Cable 9.1 m 1

Part No. Description Metric Equiv Quantity
124567 1" x 8" Drilled Fiberglass Insulator 2.5 x 20.3 cm 1
190026 Formed Aluminum Bracket 5
190028 Formed Aluminum Half Washer 4
194707 4" x 24" Drilled U-Channel Bracket 10.2 x 61 cm 1
200088 1" Diameter Formed Aluminum Clamp 2.5 cm 2
290326 Warning sticker 1
321045 3/8" Aluminum Spacer 1.0 cm 2
323718 Extruded Al V-Block 1
324071 Black Plastic Insulator 1
324509 4 x 5 1/4" x 3/16" Drilled Al Bracket 10.2 x 13.3 x 0.5 cm 2
EA 1-1/4" x 72" Drilled&slotted Al Tube w/insert 3.2 x 183 cm 2
EB 1-1/8" x 48" Al Tube slotted 1 end 2.8 cm x 183 cm 2
EC 1" x 48" Aluminum Tube slotted 1 end 2.5 x 183 cm 2
ED 1/2" x 48" Aluminum Tube slotted 1 end 1.3 x 183 cm 2
EE 3/8" x 36" Aluminum Tube 1.0 x 91 cm 2
EF 1-1/8" x 18" Aluminum Tube drilled 1 end 2.8 cm x 45.7 cm 1
LCA 40 Meter Loading Coil 2
MNX740 X740 Matching Network 1
XHR 3/8" x 34 1/2" Aluminum Rod drilled in center 1.0 x 87.6 cm 4
X79FS 1/2" Tinned Copper Braid 6" Long with Lugs 1.2 cm x 15 cm 2

1

41
11

941
11

231

231

567

X740

2 - Element Assembly

Figure A and B show the steps required for element assembly. Identify
the parts required using the Element Subassembly Parts List. Slide EA
sections over fiberglass insulator (567) until #8 screw holes line up. Insert
screws (231) through holes and secure with lock washer (941) and nut
(11). Insert EB tubes 4” (10.2 cm) into EA slotted ends until they stop
against the EA insert tube and secure with worm clamp (412). Insert EC
tubes 4" (10.2 cm) into slotted ends of EB and secure with worm clamp
(411). Insert LCA coils 4" (10.2 cm) into slotted ends of EC and secure
with worm clamp (411). Insert ED tubes 4" (10.2 cm) into slotted ends
of LCA coils and secure with worm clamp (409). Insert EE tubes into
ED tubes and adjust the element half lengths per Chart A. Secure EE
tube with worm clamp (407). Place plastic caps (77) on ends of EE

Center Element

Frequency Half Length

(MHz) Inches Meters

7.000 250 6.35

7.075 248 6.30

7.150 246 6.25

7.225 244 6.20

7.300 242 6.15

ID Part # Description Dimensions Qty

11 010011 SS Nut #8-32 2

26 290326 Warning 1

41 011941 SS Lock #8 2

77 050077 Black 3/8’ 2

231 010231 SS Machine #8-32 x 1-3/4” 2

407 030407 Worm 5/8” 2

409 030409 Worm 11/16” 2

411 030411 Worm 1-1/8” 4

412 030412 Worm 1-1/2” 2

567 124567 Fiberglass 1” x 8” 1

EA Aluminum 1-1/4” x 72” 2

EB Aluminum 1-1/8” x 48” 2

EC Aluminum 1” x 48” 2

ED Aluminum 1/2” x 48” 2

EE Aluminum 3/8” x 36” 2

LCA LCA Loading 2

Sticker

Washer

Plastic Cap (0.9 cm)

Screw (4.4 cm)

Clamp (1.6 cm)

Clamp (1.7 cm)

Clamp (2.9 cm)

Clamp (3.8 cm)

Insulator (2.5 x 20.3)

Tube (3.2 x 183 cm)

Tube (2.8 x 183 cm)

Tube 2.5 x 183 cm)

Tube (1.3 x 183 cm)

Tube (1.0 x 91 cm)

Coil

EA

EA

26

412

EB

Element Half Length

411

EC

Figure B

2

411

LCA

409

ED

Figure A

407

EE

77