DX Engineering SkyHawk 3X10 User manual

SkyHawk 3X10
20/15/10 Meter Tri-Band
Yagi Antenna
DXE-3X10-INS Rev 1b
© DX Engineering 2017
1200 Southeast Ave. - Tallmadge, OH 44278 USA
Phone: [phone] ∙ Tech Support and International: [phone]
Fax: [phone] ∙ E-mail: DXEngi[email protected]

2
DX Engineering SkyHawk 3X10
Congratulations on the purchase of your DX Engineering SkyHawk 3X10. You now possess the
finest computer optimized tri-band on the market. The SkyHawk
features low weight, zero mast torque, a balanced beam and high wind
survival. Corrosion and UV resistant materials are used throughout its
construction. Only stainless steel fasteners and rivets are used. Custom
designed aluminum extrusions make assembly a snap. Multiple wall
boom construction, eliminating the need for stays, coupled with ultra
thin trap-free riveted elements significantly reduces wind load.
DX Engineering SkyHawk Tri-Band Yagi Antennas are the choice of experienced DXers, especially if
your interest is HF contesting. The DX Engineering SkyHawk provides the highest payback in
performance and operating pleasure compared to any other single component in your station.
This well-designed, single-tower system offers outstanding performance without the headaches of
maintaining more substantial antenna farms. DX Engineering SkyHawk antenna reflects the latest
computer-optimized design for maximum gain and bandwidth. It is built from the finest materials,
including all stainless steel hardware.
The SkyHawk antenna offers minimal wind-loading for its size and is torque-balanced to reduce wear and
tear on your rotor. Assembly is easy, as tower top adjustments have been eliminated and the elements are
truly locked in place.
DX Engineering SkyHawk features include:
EZ-mount system for attaching antenna to mast
All parts de-burred
Stainless steel pop-riveted elements
Quality COMTEK balun and balun mounting system
No user adjustment required - just assemble and put it up
Additional specifications include:
20 meters:
Three elements
Effective boom length: 23 ft.
VSWR: less than 1.4:1 between 14.0 and 14.35 MHz, measured at feed-point
Front to back: >20 dB across the entire band
F/B peaks at 14.150 MHz at 21 dB
Gain: better than 7 dBi across band
7.4 dBi gain at 14.350 MHz

3
15 meters:
Three elements
Effective boom length: 15 ft., 6 in.
VSWR: less than 1.5:1 between 21.0 and 21.45 MHz, measured at feed-point
Front to back: >16 dB across the entire band
F/B peaks at 21.350 at 24.5 dB
Gain: better than 7 dBi across band
7.6 dBi gain at 21.45 MHz
10 meters:
Four elements
Effective boom length: 16 ft., 9 in.
VSWR: less than 1.5:1 between 28.0 and 28.9 MHz, measured at feed-point
Front to back: >14 dB across the entire band
F/B peaks at 28.5 at 15 dB
Gain: better than 7.7 dBi across band
9.2 dBi gain at 28.9 MHz
NOTE: ALL DIMENSIONS IS THIS INSTRUCTION ARE IN INCHES (MILLIMETERS)
UNL ESS OTHERWISE NOTED.
Required Tools
Rivet tool: POP Rivetool PRG 430, POP Rivetool PRGIII or equivalent
Flat blade screwdriver
Nut Driver: 11/32”and 3/8”nut driver
Wrench: 7/16”and 1/2”
Pair of saw horses or similar support
Permanent marker
Before You Start
WARNING: INSTALLATION OF THIS PRODUCT NEAR POWER LINES IS DANGEROUS.
FOR YOUR SAFETY FOLLOW THE INSTALLATION INSTRUCTIONS.
WARNING: AT NO TIME DURING ASSEMBLY, INSTALLATION, ADJUSTMENT, OR
OPERATION SHOULD ANY PART OF THIS PRODUCT BE ALLOWED TO COME INTO
CONTACT WITH ELECTRIC POWER LINES, NOR SHOULD THIS PRODUCT BE
INSTALLED IN SUCH A WAY T HA T ANY PART OF IT MAY CONTACT POWER LINES
DURING NORMAL OPERATION OR IN THE EVENT OF STRUCTURAL FAILURE.
FAILURE TO EXERCISE EXTREME CARE IN THIS M A TTER CAN RESULT IN DAMAGE
TO PROPERTY, PERSONAL INJURY OR DEA TH.

4
Before you start assembling the antenna, read through the instructions completely, paying special
attention to the diagrams. When you unpack the box, do so on a surface where you will not lose
small parts. Check the parts against the PARTS LIST, identifying each part carefully.
NOTE: Check to see that all parts are present before beginning assembly.
Installation Notes
CHOOSING AN INSTALLATION SITE: As with all directional antennas, care must be taken in
the choice of an installation site for your SkyHawk 3X10. Select a place clear of power lines or
other obstructions. The SkyHawk 3X10 should be mounted at least 30 ft (9.1 m) above the ground
for proper operation. If the SkyHawk 3X10 is mounted a full-wave above ground, the takeoff angle
is 14° with a minor lobe at 40° or so. For a 1/2-wave it’s closer to 20°. At mounting heights below
1/2-wave the takeoff angle is much greater than 20°. There’s no easy way to calculate it, but there
are graphs for wave angles at heights of 1/4, 1/8 and so on in any edition of the A.R.R.L. Antenna
Handbook. The SkyHawk 3X10 should be able to rotate without hitting anything. Finally, it
should not be near any large masses of metal, like metal roofing or siding. Plan your installation so
that metallic guy wires are broken up with compression insulators and no other antennas are nearby,
i.e. dipoles mounted right under the beam.
MASTS AND GUYING: In order to avoid coupling between antenna elements and guy wires that
can de- tune the antenna it may be necessary to break up the guy wires with insulators. If the
separation between the antenna and the highest set of guys is less than 15' (4.6m) it would be a good
idea to use insulators on each of the uppermost guys at intervals of 10' (3m). Place the first
insulator on each guy AT THE MAST OR TOWER, for that too is a conductor that can be coupled
to the antenna by any horizontal or near-horizontal guy wire connected to it.
Rivet Installation
The elements of your SkyHawk 3X10 are assembled with two or three blind rivets per joint. Blind
rivets were chosen to provide fast, strong, reliable, vibration proof assembly, with high grip and
pull-up strengths. Open end stainless steel rivets are used because they provide better than 80%
more shear and tensile strength than closed end aluminum rivets. Blind rivets are easily set by:
1. Line up the holes in each tube as shown in the diagram.
2. Insert a blind rivet in each hole.
3. Making sure the rivet is fully seated, set the rivet with rivet tool.
4. Repeat step 3 for the other rivets.
If for some reason you need to remove a blind rivet: Blind rivets may easily be removed by
drilling through them with a 1/8(3) drill bit. Be careful not to drill through the entire element and
be sure to remove any remnants left from the removed rivet.

5
Fastener Assembly
Installing and tightening fasteners is a simple procedure but one which is often done incorrectly.
Tightening fasteners to the proper torque keeps bolts tight, increases joint strength, creates friction
between parts to resist shear and improves the fatigue resistance of the connection. Unfortunately
fasteners are usually over tightened causing them to fracture or at least causing thread damage
making them impossible to disassemble.
It is strongly recommended that a lubricant such as JTL-12555 Jet-Lube SS-20 Pure Copper Anti-
Seize be used on the threads to reduce friction which allows the fastener to be properly tensioned.
The best way to properly tension a fastener is to tighten the nut until the lock washer is flat and then
tighten it no more than an additional one quarter turn. This rule should be followed except for U-
bolts and the 1/4 x 2-3/4(70) boom to saddle screw where one additional full turn is required.
Tubing Assembly
In order to decelerate oxidation and to improve electrical conductivity a high quality RF conductive
anti-oxidizing compound should be used. JTL-12555 Jet-Lube SS-30 is an ideal electrical joint
compound that ensures proper electrical connections between aluminum and copper metal parts
such as conductors, telescoping aluminum tubing, or other antenna and grounding parts. Apply a
thin layer to each metal to metal antenna connection with a brush or clean cloth. Be careful not to
accumulate excess material on other parts or yourself as it’s quite difficult to remove and virtually
impossible to clean out of clothing.
Parts List
10 Meter Reflector
00585SZC
Qty
Description
Size
Part Number
□
1
Element Section A 10M
3/4(19) x 28(711)
00589RZC
□
2
Element Section B 10M
5/8(16) x 35-7/8(911)
00531BAC
□
2
Element Section C 10M Reflector
1/2(12) x 71-1/8(1,807)
00533BAC
10 Meter Driven
00993SZC
Qty
Description
Size
Part Number
□
1
Element Insulator Driven
00985FAC
□
2
Element Section A 10M Driven
3/4(19) x 24(356)
00974RZC
□
2
Element Section B 10M Driven
5/8(16) x 38(965)
00986BAC
□
2
Element Section C 10M Driven
1/2(13) x 68-43/64(1,744)
00987BAC
10 Meter Director 1
00587SZC
Qty
Description
Size
Part Number
□
1
Element Section A 10M
3/4(19) x 28(711)
00589RZC
□
2
Element Section B 10M
5/8(16) x 35-7/8(911)
00531BAC
□
2
Element Section C 10M Director 1
1/2(13) x 63-23/32(1,618)
00535BAC

6
10 Meter Director 2
00588SZC
Qty
Description
Size
Part Number
□
1
Element Section A 10M
3/4(19) x 28(711)
00589RZC
□
2
Element Section B 10M
5/8(16) x 35-7/8(911)
00531BAC
□
2
Element Section C 10M Director 2
1/2(13) x 66-9/16(1,640)
00536BAC
15 Meter Reflector
00580SZC
Qty
Description
Size
Part Number
□
1
Element Section A 15M
3/4(19) X 47-7/8(1,216)
00581RZC
□
2
Element Section B 15M
5/8(16) X 59-7/8(1,521)
00530BAC
□
2
Element Section C 15M
1/2(13) X 71-7/8(1,826)
00532BAC
□
2
Element Section D 15M Reflector
3/8(10) X 28-15/32(723)
00540BAC
15 Meter Driven
00994SZC
Qty
Description
Size
Part Number
□
1
Element Insulator Driven
00985FAC
□
2
Element Section B 15M Driven
3/4(19) X 23-7/8(606)
00975RZC
□
2
Element Section C 15M Driven
5/8(16) X 59-7/8(1,521)
00988BAC
□
2
Element Section D 15M
1/2(13) X 71-7/8(1,826)
00532BAC
□
2
Element Section D 15M Driven
3/8(10) X 23-5/8(600)
00989BAC
15 Meter Director
00584SZC
Qty
Description
Size
Part Number
□
1
Element Section A 15M
3/4(19) X 47-7/8(1,216)
00581RZC
□
2
Element Section B 15M
5/8(16) X 59-7/8(1,521)
00530BAC
□
2
Element Section C 15M
1/2(13) X 71-7/8(1,826)
00532BAC
□
2
Element Section D 15M Director
3/8(10) X 14-5/64(358)
00542BAC
20 Meter Reflector
00576SZC
Qty
Description
Size
Part Number
□
1
Element Section A 20M
1(25) X 47-7/8(1,216)
00577RZC
□
2
Element Section B 20M
7/8(22) X 47-7/8(1,216)
00524BAC
□
2
Element Section C 20M
3/4(19) X 71-7/8(1,826)
00526BAC
□
2
Element Section D 20M
5/8(16) X 65-7/8(1,673)
00529BAC
□
2
Element Section E 20M
1/2(13) X 47-7/8(1,216)
00537BAC
□
2
Element Section F 20M Reflector
3/8(10) X 47-7/32(1,199)
00538BAC
20 Meter Driven
00521FAC
Qty
Description
Size
Part Number
□
1
Element Insulator 20M Driven
00521FAC
□
2
Element Section A 20M Driven
1(25) X 23-7/8(606)
00572RZC
□
2
Element Section B 20M Driven
7/8(22) X 47-7/8(1,216)
00525RZC
□
2
Element Section C 20M
3/4(19) X 71-7/8(1,826)
00526BAC
□
2
Element Section D 20M
5/8(16) X 65-7/8(1,673)
00529BAC
□
2
Element Section E 20M
1/2(12) X 47-7/8(1,216)
00537BAC
□
2
Element Section F 20M Driven
3/8(10) X 28-3/16(716)
00990BAC

7
20 Meter Director
00579FAC
Qty
Description
Size
Part Number
□
1
Element Section A 20M
1(25) x 47-78(1,216)
00577RZC
□
2
Element Section B 20M
7/8(22) X 47-7/8(1,216)
00524RZC
□
2
Element Section C 20M
3/4(19) X 71-7/8(1,826)
00526BAC
□
2
Element Section D 20M
5/8(16) X 65-7/8(1,673)
00529BAC
□
2
Element Section E 20M
1/2(12) X 47-7/8(1,216)
00537BAC
□
2
Element Section F 20M Director
3/8(10) X 10-1/2(267)
00543BAC
Boom
Qty
Description
Size
Part Number
□
1
Boom Section A
2(51) X 71-7/8(1,826)
00601BBC
□
1
Boom Section B
2(51) X 71-7/8(1,826)
00602BBC
□
1
Boom Section C
2(51) X 71-7/8(1,826)
00603BBC
□
1
Boom Section D
2(51) X 71-7/8(1,826)
00604BBC
□
1
Boom Splice A
1-7/8(48) X 71-3/4(1,822)
00605BBC
□
1
Boom Splice B (Double Wall Tube)
1-7/8(48) X 71-3/4(1,822)
00655SZC
□
1
Boom Splice C
1-7/8(48) X 71-3/4(1,822)
00607BBC
□
1
Element Compensator
1.9(48) X 56(1,422)
00562FAC
Hardware
Qty
Description
Size
Part Number
□
4
Element Saddle
1-1/4
0053EAC
□
10
Element Saddle
1
0054EAC
□
11
Boom Saddle
0555EAC
□
1
Mast Saddle
0556EAC
Boom/Mast Plates
00837SZC
Qty
Description
Part Number
□
2
1/4-20 HEX NUT 18-8 (7/16 X 7/32)
00056JAV
□
2
1/4 SPLIT RING LW 18-8
00057JAV
□
2
#10 SPLIT RING LW 18-8
00133JZV
□
2
#10-32 X 3/8 PHIL RND HD MS 18-8
00191JZV
□
1
MAST PLATE
00551BAC
□
1
BOOM PLATE
00552BAC
□
2
5/16-18 X 1 HEX WAS HD CS 18-8
00567JAC
□
4
5/16-18 HEX NUT 18-8 (1/2 X 17/64)
00568JAC
□
4
5/16 SPLIT RING LW 18-8
00570JAC
□
2
1/4-20 X 2-3/4 PHIL RND HD MS 18-8
00595JAC
□
2
5/16-18 X 2 X 3-1/8 U-BOLT 18-8
00597JAC
□
2
U-BOLT SADDLE 2
00598EAC
□
4
5/16 FLAT WASHER 18-8 (11/32 X 11/16 X 1/16)
00600JAC
□
4
5/16-18 HEX SERRATED FLANGE NUT 18-8 (1/2 X 9/32)
00834JZC
□
2
5/16-18 X 1-1/4 HEX HD CS 18-8
00835JZC
COMTEK Balun Assembly
DXE-BAL-
YAGI-UPG
Qty
Description
□
1
COMTEK BALUN WITH MOUNTING PLATE ASSEMBLY and Hardware
□
1
BALUN CLAMP ASSEMBLY

8
Boom Compensator
00839SZC
consists of the
parts listed
Qty
Description
□
3
#10 SPLIT RING LW 18-8
□
3
#10-24 HEX NUT 18-8 (3/8 X 1/8)
□
3
#10-24 X 3/4 PHIL RND HD MS 18-8
□
2
BOOM COMPENSATOR BRACKET
□
1
BOOM COMPENSATOR
Boom Hardware Package
00991SZC
consists of the
parts listed
Qty
Description
□
43
1/4-20 HEX NUT 18-8 (7/16 X 7/32)
□
43
1/4 SPLIT RING LW 18-8
□
2
1/4-20 X 2 X 2-11/16 U-BOLT 18-8
□
28
1/4-20 X 5/8 PHIL RND HD MS 18-8
□
11
1/4-20 X 2-3/4 PHIL RND HD MS 18-8
□
2
PROTECTIVE CAP 2
Driven Element Boom Hardware Package
00992SZC
consists of the
parts listed
Qty
Description
□
12
1/4-20 HEX NUT 18-8 (7/16 X 7/32)
□
12
1/4 SPLIT RING LW 18-8
□
2
COMPRESSION CLAMP SMALL ADJUSTABLE
□
12
1/4-20 X 5/8 PHIL RND HD MS 18-8
□
4
ELEMENT SADDLE 1 DRIVEN
□
2
ELEMENT SADDLE 1-1/4 DRIVEN
□
2
ELEMENT SPACER
□
2
FEED STRAP
Element Hardware Package
00996SZC
consists of the
parts listed
Qty
Description
□
6
# 8 SPLIT RING LW 18-8
□
6
# 8-32 HEX NUT 18-8 (11/32 X 1/8)
□
8
PROTECTIVE CAP 1/2
□
12
PROTECTIVE CAP 3/8
□
6
# 8-32 X 1-1/2 PHIL RND HD MS 18-8
□
136
1/8 X 17/64 POP RIVET 18-8

9
Assembly - Driven Elements
10DR
15DR
20DR
□
□
□
1.
Locate the bag for the element you wish to assemble.
□
□
□
2.
Locate one of the B element sections and slide the side with one hole into one of the A
element sections so all holes line up.
NOTE: If the holes don’t line up exactly, rotate one or both of the elements 180°.
□
□
□
3.
Insert one end of the element insulator into the above assembly. Line up the holes and
pass a # 8 x 1-1/2 in (38 mm) screw followed by a # 8 lock washer and hex nut. Hand
tighten
□
□
□
4.
Slide the side with one hole of the other B element section into the remaining A
element section so all the holes line up.
□
□
□
5.
Insert the other end of the element insulator into the above assembly. Line up the hole
sand pass a # 8 x 1-1/2 in (38 mm) screw followed by a # 8 lock washer and hex nut.
Hand tighten
□
□
6.
Locate one of the C element sections and insert the side with the two holes furthermost
from the end into one of the B element sections. Line up all the holes and secure with
two rivets.
□
7.
Place a large cap over each element tip
□
8.
Identify the completed 10 meter element section with a felt tip marker.
□
9.
Locate one of the C element sections and insert the side with the three holes
furthermost from the end into one of the B element sections. Line up all the holes and
secure with three rivets.
□
10.
Insert the other C element section into the other B element section as above and secure
with three rivets.
□
□
11.
Locate one of the D element sections and insert the side with the two holes furthermost
from the end into one of the C element sections. Line up all the holes and secure with
two rivets.
□
□
12.
Insert the other D element section into the other C element section as above and secure
with two rivets.
□
13.
Place a small cap over each element tip.
□
14.
Identify the completed 15 meter element section with a felt tip marker.
□
15.
Locate one of the E element sections and insert it into one of the D element sections.
Line up all the holes and secure with two rivets.
□
16.
Insert the other E element section into the other D element section as above and secure
with two rivets.
□
17.
Locate one of the F element sections and insert it into one of the E element sections.
Line up all the holes and secure with two rivets.
□
18.
Insert the other F element section into the other E element section as above and secure
with two rivets.
□
19.
Place a small cap over each element tip
□
20.
Identify the completed 20 meter element section with a felt tip marker.

10
Assembly - Elements
10D2
10D1
10R
15D
15R
20D
20D
□
□
□
□
□
□
□
1.
Locate the bag for the element you wish to assemble.
□
□
□
□
□
□
□
2.
Locate one of the B element sections and insert the side with the three
holes furthermost from the end into one side of the A element section.
Line up all the holes and secure with rivets.
□
□
□
□
□
□
□
3.
Insert the other B element section into the other side of A element section
as above and secure with rivets.
□
□
□
□
□
□
□
4.
Locate one of the C element or tip sections and insert the side with the
two or three holes furthermost from the end into one of the B element
sections. Line up the all the holes and secure with rivets.
□
□
□
□
□
□
□
5.
Insert the other C element or tip section into the other B element section
as above and secure with rivets.
□
□
□
6.
Place a small cap over each element tip
□
□
□
7.
Identify the completed 10 meter element section with a felt tip marker.
□
□
□
□
8.
Locate one of the D element or tip sections and insert the side with the
two holes furthermost from the end into one of the C element sections.
Line up all the holes and secure with two rivets.
□
□
□
□
9.
Insert the other D element or tip section into the other C element section
as above and secure with two rivets.
□
□
10.
Place a small cap over each element tip
□
□
11.
Identify the completed 15 meter element section with a felt tip marker.
□
□
12.
Locate one of the E element sections and insert it into one of the D
element sections. Line up all the holes and secure with two rivets.
□
□
13.
Insert the other E element section into the other D element section as
above and secure with two rivets.
□
□
14.
Locate one of the tip sections and insert it into one of the E element
sections. Line up all the holes and secure with two rivets.
□
□
15.
Insert the other tip section into the other E element section as above and
secure with two rivets.
□
□
16.
Place a large cap over each element tip.
□
□
17.
Identify the completed 20 meter element section with a felt tip marker.

11
Assembly - Boom
Each boom has been assembled and each section numbered for easy reassembly. In the event that
the numbers have worn off, each section may be identified using the dimensions given in the
pictorial found on the pullout sheet.
□
1.
Find boom section A which may be identified with the number “1” at one end and boom
splice A which may be identified with the “1” and “2” in the center.
□
2.
Place a saddle over the holes closest to the unidentified end of boom section A and secure
with a 1/4 x 2-3/4(70) screw, lock washer and hex nut.
□
3.
Slide the end identified with “1” of boom section A over the “1” side of boom splice A and
lineup the holes.
□
4.
Place a boom saddle over the above set of holes and secure with a 1/4 x 2-3/4(70) screw,
lock washer and hex nut.
□
5.
Repeat the above for boom section B and boom splice B placing a boom saddle over each
set of holes and securing with a 1/4 x 2-3/4(70) screw, lock washer and hex nut
□
6.
Slide the “4” end of boom section C over boom splice B and place boom saddles over the
first two sets of holes and secure with 1/4 x 2-3/4(70) screws, lock washers and hex nuts.
□
7.
Line up the four holes of the mast saddle with those in the tube above and secure with two
1/4 x 2-3/4(70) screw, lock washer and hex nut.
□
8.
Attach, with the threaded holes up, the boom plate to the boom saddle using two #10 x
3/8(10) screws and lock washer.
□
9.
Insert two 5/16 x 1(25) hex head screws and tighten.
□
10.
Start a flange nut on each screw.
NOTE: The above flange nuts must kept loose enough to allow easy insertion into the mast
plate.
□
11.
Continue assembling boom splice C and boom section D adding boom saddles as above
except for the second and third set of holes on the end of boom section D.
□
12.
Line up the boom compensator brackets and boom compensator.
□
13.
Insert a #10 x 3/4(19) screw through one of the holes, followed by a #10 lock washer and
hex nut. Hand tighten.
□
14.
Repeat the above step for the remaining two holes.
□
15.
Line up the holes of two boom saddles with the second and third set of holes from the end
of boom section D.
□
16.
Position the boom compensator over the two boom saddles and line up all four holes and
secure with two 1/4 x 2-3/4(70) screw, lock washers and hex nuts.
□
17.
Tighten the #10 hex nuts on the boom compensator.
□
18.
Place a boom cap over each end of the boom.
This completes assembly of the boom.
NOTE: The end of the boom with the boom compensator is the FRONT of the antenna.

12
Assembly - Driven Elements to Boom
In the following steps, each driven element will be assembled onto the boom. You will find that
assembly will be much easier if the boom is supported by a saw horse or similar support at either
end. Refer to the ELEMENT POSITION page at the end of this instruction for proper placement.
□
1.
Rotate the boom so the flat portion of the boom saddles are facing down.
10DR
15DR
20DR
□
□
□
2.
Insert a 1/4 x 5/8(16) screw through each hole on one side of the boom saddle.
□
□
□
3.
Position an element saddle as shown followed by a 1/4 lock washer and hex nut.
Tighten only enough so the nut won’t fall off (two or three turns).
□
□
□
4.
Slide one side of a driven element through the element saddle.
□
□
□
5.
Assemble an element saddle on the other side and secure with 1/4 x 5/8(16) screws,
lock washers and hex nuts.
□
□
□
6.
Center the element insulator and position the nut side of the screws down.
Repeat steps 2 through 6 for the remaining two driven elements.
IMPORTANT! Driven element saddles are narrower than the others and are not
interchangeable.
NOTE: The two large element saddles are used on 20 meter element while the four smaller
saddles are for 10 and 15 meters.

13
□
7.
Remove the #8 hex nuts and lock washers from each driven element.
□
8.
Place one of the feed straps onto the driven elements as shown and secure with #8 lock
washers and hex nuts. Do not tighten hex nuts at this time.
□
9.
Place the remaining feed strap onto the driven elements and secure with #8 lock washers
and hex nuts. Once again, do not tighten the hex nuts at this time.
□
10.
Align all three center insulators.
□
11.
Tighten the #8 hex nuts starting with the 15 meter driven element, followed by the 10 and
then 20 meter driven elements.
□
12.
Straighten the feed straps making sure they are parallel to the boom.
□
13.
If necessary, realign the element insulators.
□
14.
Tighten the 1/4 hex nuts on all of the driven element saddles.
Assembly - Elements to Boom
In the following steps, each element and the element compensator will be assembled onto the boom.
You will find that assembly will be much easier if the boom is supported by a saw horse or similar
support at either end. Refer to the pictorial on the pullout sheet and the ELEMENT POSITION
page at the end of this instruction for proper placement.
NOTE: The elements may be slid through both clamps after they are installed.
IMPORTANT: LARGE ELEMENT SADDLES ARE USED TO SECURE THE TWO 20 METER
ELEMENTS TO THE BOOM. THE REMAINING ELEMENTS ARE SECURED WITH SMALL
ELEMENT SADDLES.
20R
20D
15R
15D
10R
10D1
10D2
□
□
□
□
□
□
□
1.
Insert a 1/4 x 5/8(16) screw through each hole on the boom saddle.
□
□
□
□
□
□
□
2.
Position an element saddle on one side followed by a 1/4 lock washer and
hex nut. Tighten only enough so the nut won’t fall off (two or three
turns).
□
□
□
□
□
□
□
3.
Repeat the above procedure for the other side of the element saddle.
□
□
□
□
□
□
□
4.
Slide the element through both element saddles.
□
□
□
□
□
□
□
5.
Center the element insulator and position the rivet side of the element
down. Securely tighten all four fasteners.
Repeat steps 1 through 5 for the remaining elements.

14
□
6.
Insert a 1/4 x 2(51) U-bolt into the left hand pair of holes on the second boom saddle. Secure it
with 1/4 lock washers and hex nuts
□
7.
Insert a second 1/4 x 2(51) U-bolt into the right hand pair of holes on the same boom saddle.
Secure it with 1/4 lock washers and hex nuts.
□
8.
Insert the element compensator through the two U-bolts and center it.
□
9.
Tighten the nuts on each U-bolt leg evenly. NOTE: Do not over tighten the U-bolts as this will
only deform the compensator and possibly break it.
□
10.
Sight down the boom and make sure that the elements all line up.
□
11.
Straighten any out of line elements and re-tighten boom saddle screws as necessary.
Assembly - Element Spacer
The element spacers are designed to maintain the relationship between the three driven elements
providing unchanging performance under a wide variety of operating conditions. They will be
placed on element sections 20C, 15C and 10DR.
□
1.
Slide the large hole of one of the element spacers over the 20 meter driven element. As you
approach the 15 meter driven element, slide it through the center hole followed by the 10 meter
element through the end hole.
NOTE: Position the notched side of the holes to slide over the rivets.
□
2.
Position the element spacer so it rests against the end of element 20C.
□
3.
Slide one of the hose clamps over the 20 meter driven element until you reach the element
spacer. Securely tighten the hose clamp leaving about a 1/16" of clearance between it and the
spacer.
Repeat steps 1 through 3 for the remaining element spacer.

15
Assembly - Balun
□
1.
Install the Balun mounting plate with clamps and coax clamp to the rear of the 20 meter driven
element as shown. Do not tighten the Balun Clamps until step 5.
□
2.
Verify the COMTEK Balun leads are facing the 20 meter driven element.
□
3.
Attach one of the balun strap to one of the screws on the 20 meter driven element using the
feedline strap and hardware as shown above. Adjust the balun position so there is no strain on
the feedline strap.
□
4.
Attach the second Balun feedline strap as above.
□
5.
Tighten the Balun mounting clamps in place.
NOTE: The following three steps may completed after the antenna is installed on the tower.
□
6.
Install the coax clamp assembly behind the COMTEK Balun as shown.
□
7.
Connect the feed line to the COMTEK Balun
□
8.
Slide the piece of tubing over the feed line and insert this assembly into the small clamp.
□
9.
Seal the Balun connection with the supplied coax seal.

16
Final Assembly - Mast Plate
The mast plate is supplied with hardware to mount to a 2(51) mast. Additional holes have been
provided to accommodate a 2-3/8(60) mast with customer provided hardware.
□
1.
Position a 2(51) U-bolt saddle over the second pair of holes from the top as
shown.
□
2.
Pass a 5/16 x 2(51) U-bolt through the 2(51) U-bolt saddle and mast plate.
Secure with a 5/16 in flat washers, lock washers and hex nuts.
□
3.
Position a 2(51) U-bolt saddle over the second pair of holes from the bottom
as shown.
□
4.
Pass a 5/16 x 2(51) U-bolt through the 2(51) U-bolt saddle and mast plate.
Secure with a 5/16 in flat washers, lock washers and hex nuts.
□
5.
Slide this assembly over the mast, with the top of the large end of the
keyhole facing up and securely tighten.
WARNING: IT IS EXTREMELY IMPORTANT THAT EACH NUT IS EVENLY
TIGHTENED. APPLYING UNEQUAL AMOUNTS OF TORQUE TO THE U-BOLT LEGS
MAY LEAD TO PREMATURE FAILURE
Assembly - Boom to Mast Assembly
□
1.
Line up the two flange nuts located on the boom plate with large hole in each keyhole on the
mast plate.
□
2.
Pass the flange nuts through and let the screws drop into the slots.
□
3.
Insert a 5/16 x 1(25) washer head screw through on of the lower holes. Tighten the bolt and
secure with a flange nut.
□
4.
Insert a 5/16 x 1(25) washer head screw through the remaining lower hole. Tighten the bolt and
secure with a flange nut.
□
5.
Securely tighten the upper flange nuts.

17
Element Position

18
Element Assembly
All dimensions are +/- 1/4(6)
Element section dimensions
are reference only
Dimensions are in
inches (millimeters) unless
otherwise noted

19
Boom and Element
to Boom Assembly
All dimensions are +/- 1/4(6)
Element section dimensions
are reference only
Dimensions are in
inches (millimeters) unless
otherwise noted.

20
Technical Support
If you have questions about this product, or if you experience difficulties during the installation, contact DX
Engineering at [phone]. You can also e-mail us at:
[e-mail]
For best service, please take a few minutes to review this manual before you call.
Warranty
All products manufactured by DX Engineering are warranted to be free from defects in material and
workmanship for a period of one (1) year from date of shipment. DX Engineering’s sole obligation under
these warranties shall be to issue credit, repair or replace any item or part thereof which is proved to be other
than as warranted; no allowance shall be made for any labor charges of Buyer for replacement of parts,
adjustment or repairs, or any other work, unless such charges are authorized in advance by DX Engineering.
If DX Engineering’s products are claimed to be defective in material or workmanship, DX Engineering shall,
upon prompt notice thereof, issue shipping instructions for return to DX Engineering (transportation-charges
prepaid by Buyer). Every such claim for breach of these warranties shall be deemed to be waived by Buyer
unless made in writing. The above warranties shall not extend to any products or parts thereof which have
been subjected to any misuse or neglect, damaged by accident, rendered defective by reason of improper
installation, damaged from severe weather including floods, or abnormal environmental conditions such as
prolonged exposure to corrosives or power surges, or by the performance of repairs or alterations outside of
our plant, and shall not apply to any goods or parts thereof furnished by Buyer or acquired from others at
Buyer’s specifications. In addition, DX Engineering’s warranties do not extend to other equipment and parts
manufactured by others except to the extent of the original manufacturer’s warranty to DX Engineering. The
obligations under the foregoing warranties are limited to the precise terms thereof. These warranties provide
exclusive remedies, expressly in lieu of all other remedies including claims for special or consequential
damages. SELLER NEITHER MAKES NOR ASSUMES ANY OTHER WARRANTY WHATSOEVER,
WHETHER EXPRESS, STATUTORY, OR IMPLIED, INCLUDING WARRANTIES OF
MERCHANTABILITY AND FITNESS, AND NO PERSON IS AUTHORIZED TO ASSUME FOR DX
ENGINEERING ANY OBLIGATION OR LIABILITY NOT STRICTLY IN ACCORDANCE WITH THE
FOREGOING.
©DX Engineering 2017
DX Engineering®, DXE®, DX Engineering, Inc.®, Hot Rodz®, Maxi-Core®, DX Engineering
THUNDERBOLT®, DX Engineering Yagi Mechanical®, EZ-BUILD®, TELREX®, Gorilla Grip®Stainless
Steel Boom Clamps, Butternut®, SkyHawk™, SkyLark™, SecureMount™, OMNI-TILT™, RF-PRO-1B®,
AFHD-4®are trademarks of PDS Electronics, Inc. No license to use or reproduce any of these trademarks or
other trademarks is given or implied. All other brands and product names are the trademarks of their
respective owners.
Specifications subject to change without notice.