DX Engineering Thunderbolt DXE-7580VA-1 User manual

75 and 80 Meter
DX Engineering
Thunderbolt™
Monoband
Vertical Antenna
DXE-7580VA-1
US Patent No. 8,130,168
DXE-7580VA-1-INS Revision 4b
© DX Engineering 2012
P.O. Box 1491 ∙ Akron, OH 44309-1491 USA
Phone: [phone] ∙ Tech Support and International: [phone]
Fax: [phone] ∙ E-mail: [email protected]

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Table of Contents
Introduction & Features
2
Warning
3
Tools Required
3
Manual Updates and Information
4
Installation Sequence
4
Site Selection
4
Mounting Pipe
4
Coaxial Cable to Mounting Pipe
5
Radial System
6
Assembly Notes
6
Radial Plate to Mounting Pipe
7
Attaching Ground Radial Wires to the Radial Plate
8
Overall Pivot and Antenna Base Assembly Drawing
9
Pivot Base and Lower Antenna Assembly
10
Mounting and using the Optional DXE-VRW-1 Manual Winch
18
General Information about Aluminum Tubing
21
Assembling the Vertical Sections
22
Mating the Vertical Elements to the Pivot Base Assembly
30
75/80 Coil Assembly and Installation
31
Base Matching Network Assembly and Installation
34
Optional DXE-7580-THK Capacity Hat Assembly and Installation
35
Tuning the Vertical
38
Operation of the DXE-7580VA-1 for CW portion of the band
40
Locking the Pivot Base
40
DXE-7580VA-1 Part Lists
Pivot Base Assembly
41
Optional DXE-VRW-1 Manual Winch Assembly
41
Feedpoint Hardware
41
Vertical Elements Assembly
42
75/80 Coil Assembly
42
Base Matching Network Assembly
42
Optional DXE-7580-THK Capacity Hat Assembly
43
Additional Material Needed but not Supplied
43
Suggested Parts Not Included
44
Optional Accessory Items
45
Technical Support and Warranty
47

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Introduction
Congratulations on obtaining your DX Engineering DXE-7580VA-1 Vertical Antenna! Now you
can have a high-performance vertical antenna specifically for the 75/80 meter band! The DX
Engineering 53 to 55-foot Monoband Vertical Antenna supplies the highest possible performance
with simple, sleek appearance. Achieve the strongest possible presence at your power level and be
competitive!
The DX Engineering DXE-7580VA-1 80/75 meter band vertical antenna is tunable down to 3650
kHz center frequency with 300 kHz bandwidth. This means that operation on the CW DX
frequencies and DX Phone frequencies is within range of most radio internal tuners - no antenna
changes are necessary to switch frequencies!
The optional patented CW Optimizer DXE-7580-THK Capacity Hat Kit allows adjustment down to
3400 kHz center frequency for dedicated CW ops and military/MARS ops. The DXE-7580-THK
consists of hub and 48" adjustable rods. Easy to add to or remove from upper antenna mast with two
studded element clamps after lowering antenna.
The DX Engineering DXE-7580VA-1 is a slow taper 53 to 55-foot high Monoband Vertical
Antenna system. The vertical antenna is specifically designed to operate on 75/80 meters. Included
with this antenna system is a rugged stainless steel pivot fixture for ease of assembly and
adjustments. Engineered with 6063 corrosion-resistant aluminum tubing, stainless steel mounting
brackets and stainless steel hardware, this antenna is very durable and attractive.
Features
High Efficiency Design
High Efficiency center loaded design - strongest signal possible
5 kW SSB and CW rated - unparalleled reliability
DX Engineering Adjustable Matching Network configures the lowest SWR
Broad 2:1 SWR bandwidth - 300 kHz
Lowest possible take-off angle reduces domestic QRM signals
High Strength Pivoting Fixture - US Patent No. 8,130,168
Ultra-rugged construction starts with 3 inch OD Aircraft Grade heavy wall tubing
Self supporting - will withstand steady-state winds in excess of 50 mph without guying
(guying required under extreme wind speed conditions)
Extremely high strength heavy wall tubing made to DX Engineering specifications
Massive Extren® channel insulator
The optional DXE-VRW-1 Manual Winch for easy one-person raising and lowering of the antenna
is available from DX Engineering. You can move the DXE-VRW-1 winch between similar
antennas in a multi-antenna installation.

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This antenna system requires a heavy duty mounting pipe. Recommended installation should
provide up to 3" OD heavy wall galvanized steel pipe set in concrete. Schedule 80 pipe that is called
2-1/2" has an outside diameter of 2.875" is recommended. 36" of the mounting pipe should extend
above ground level. Depth of the mounting hole and amount of concrete is dependent on local soil
type, condition and antenna guying.
WARNING!
INSTALLATION OF ANY ANTENNA NEAR POWER LINES IS DANGEROUS
Warning:Do not locate the antenna near overhead power lines or other electric light or power
circuits, or where it can come into contact with such circuits. When installing the antenna, take
extreme care not to come into contact with such circuits, because they may cause serious injury or
death.
Overhead Power Line Safety
Before you begin working, check carefully for overhead power lines in the area you will be
working. Don't assume that wires are telephone or cable lines: check with your electric utility for
advice. Although overhead power lines may appear to be insulated, often these coverings are
intended only to protect metal wires from weather conditions and may not protect you from electric
shock
Keep your distance! Remember the 10-foot rule: When carrying and using ladders and other long
tools, keep them at least 10 feet away from all overhead lines - including any lines from the power
pole to your home.
Tools Required
Two 9/16" wrenches, (one of them should be open-end)
One 7/16" open end wrench
Two 3/4" wrenches
Medium size flat blade screwdriver or 5/16" nut driver for the element clamps
Tape measure
Felt-tip marker
Small Phillips Head Screwdriver

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Manual Updates and Information
Every effort is made to supply the latest manual revision with each product. Occasionally a manual
will be updated between the time your DX Engineering product is shipped and when you receive it.
Please check the DX Engineering web site (www.dxengineering.com) for the latest revision manual.
Please - Take the time to read the entire manual before you start assembly. There are plenty of
pictures and drawings to see, and if you read the entire manual first, you'll get a better feel for the
overall construction methods described. Assembly is not difficult, but there are a number of parts
that must go together in a certain sequence to make assembly easier.
Installation Sequence
1. Site Selection
2. Mounting Pipe
3. Coaxial Cable to Mounting Pipe
4. Radial System
5. Pivot Base Assembly (US Patent No. 8,130,168)
6. Mounting Pivot Base to Mounting Pipe
7. Antenna Assembly
8. Tuning
Site Selection
Select a mounting location clear from power lines, structures and other antennas by a minimum of
65 feet (55 + 10 ft safety rule). Consider overhead power lines, utility cables and wires. The
further away the vertical is mounted from local noise sources or other metallic objects, which can
re-radiate noise and affect the tuning, radiation pattern and SWR, the better. Determine the direction
you want the antenna to pivot and make sure there is adequate clearance (at least 65 feet).
Mounting Pipe
Use a customer supplied 2-1/2" schedule 80 galvanized steel thick-walled mounting pipe at least
7-1/2 feet long. The 2-1/2" schedule 80 galvanized steel pipe will have an outside diameter of
2.895". This will allow 4-1/2 feet below ground and 3 feet above ground.
Some manufacturers use the term DOM (drawn over mandrel) which will give you a true OD
dimension. Other types of mounting pipe may be used but due to lateral strength needed ensure the
mounting pipe is strong enough. The material most available is ASTM A513 Type 5 which is a
1020 material. Some pipe suppliers list the material as either 1020 or 1026. Type 1020 has the
following properties:
ASTM A513 (1020): Up to 2-3/4" OD with maximum wall thickness of 0.125"
Tensile: 80,000 PSI. Yield: 70,000 PSI. Elongation in 2": 15%. Rockwell Hardness: B80

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ASTM A513 (1020): Over 2-3/4" OD with wall thickness heavier than 0.125"
Tensile: 70,000 PSI. Yield: 60,000 PSI. Elongation in 2": 20%. Rockwell Hardness: B80
The following sizes of 65,000 PSI yield tubing are also suggested:
2.50" OD x 0.375" wall thickness
2.50" OD solid bar
3.00" OD x 0.25" wall thickness
Depending on your geographic location, various dealers should be able to supply the mounting post
you specify. The following dealers can supply DOM tubing: (Other dealers in your area may be a
better choice.) On Line Metal Store: www.onlinemetals.com
Speedy Metals: www.speedymetals.com
Metals Depot: www.metalsdepot.com
Note: DX Engineering does not recommend or endorse any specific vendor.
This mounting pipe must be permanently mounted in the ground, preferably in a concrete base 2
feet by 2 feet by 4 feet deep (with gravel below for drainage). The antenna system requires this type
of mounting to help withstand the lateral forces present on
the antenna during wind conditions and when operating the
pivot function. Make the hole deep enough to
accommodate at least 4 feet of pipe and 4 to 6 inches of
gravel at the bottom for drainage. Set the mounting pipe on
the gravel, use the concrete to fill around the pipe per the
concrete instructions. Fill the hole until the concrete is level
with the ground around it. Use a level on the mounting pipe
as you fill the hole to be sure the mounting pipe is
vertically straight.
Your location, landscape and ground conditions may
require different mounting solutions in order to have the
steel mounting pipe and the vertical antenna in a secure
position.
Note: Galvanized steel, rather than aluminum, is much
more suitable for mounting in concrete.
Aluminum will quickly corrode due to
incompatibility with the materials used to make
concrete.
Coaxial Cable to Mounting Pipe
The coaxial cable should be routed to the base of the antenna system and be buried below the radial
system. PVC Conduit pipe may be used to house the coaxial cable. Bury the cable 6" to 12" below
ground level.

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Radial System
The use of a radial system is a key requirement for a high performance quarter wave vertical
antenna system. With a vertical antenna system, the radials are the
second half of the antenna. The radials contribute to the radiation
efficiency of the entire vertical antenna system.
At a minimum, 32 radials, each 65 feet long, should be used with
this antenna. DXE-RADW Radial Wire, a 14 gauge stranded copper
with a black relaxed PVC insulation wire is suggested for the best
results.
The wire radials should placed as symmetrically as possible straight
from the feedpoint around the vertical antenna and spaced evenly,
regardless of how many radials are used. Do not cross or bunch any
radial wires as this nullifies their effectiveness. If you have limited space, put in as many straight
radials as you can. The radials must be connected to the shield of your feedline. The DXE-RADP-3
Stainless Steel Radial Plate is an ideal optional item which provides an excellent system for
attaching radial wires to your vertical antenna system feedpoint.
Radial wires can be laid on the roots of the grass using DXE-STPL Radial Wire Anchor Pins to
hold them down. Using enough staples will ensure the wires will not be snagged by mowers,
people, or animals. Grass will quickly overgrow the radials and it will be virtually impossible to see
them. An article describing this process is available on the DX Engineering website in the Tech
Info section. Radials can also be buried just under the surface by using a power edger to make a slit
in the soil.
Assembly Notes
Note: DXE-P8A Penetrox™A Anti-Oxidant should be used between all antenna element
sections. Penetrox™ A is an electrical joint compound to affect a substantial
electrical connection between metal parts such as telescoping aluminum tubing or
other antenna pieces. It ensures high conductivity at all voltage levels by displacing
moisture and preventing corrosion or oxidation.
Note: UMI-81343 Never-Seez® or DXE-NSBT8 Anti-Seize should be used on all clamps,
bolts and stainless steel threaded hardware to prevent galling and to ensure proper
tightening.

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Note: The following assembly instructions are based on using a customer supplied
2.895" OD Mounting Pipe, with the optional DXE-VR-1 Manual Winch,
optional DXE-RADP-3 Radial Plate, optional DXE-363-SST Bulkhead
Connector and the optional DXE-7580-THK Capacity Hat Assembly.
Radial Plate to Mounting Pipe
Place the optional DXE-RADP-3 Radial Plate over the 2.895" OD mounting pipe. Connections to
the antenna will be made via the optional DXE-363-SST bulkhead fitting SO-239 socket connector.
The DXE-RADP-3 Radial Plate comes with 20 sets of stainless steel hardware for mounting the
radial wires. It is suggested that 32 radial each 65 feet long be used, therefore additional DXE-
RADP-1HWK Radial Plate Wire Attachment Hardware Kits will be required.
Optional DXE-RADP-3 Radial Plate Mounted to a 3" OD Mounting Pipe

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Attaching Ground Radial Wires to the Radial Plate
Using the 20 sets of supplied 1/4" stainless steel hardware (Bolt, Star Washer, Flat Washer, Split
Washer, Nut) connect the optional ground radial wires to the DXE-RADP-3 Radial Plate as shown
below. Additional hardware kits are available (DXE-RADP-1HWK) that contain 20 sets of Radial
Plate Hardware.
There are optional DX Engineering Radial Wire Kits available. DXE-RADW-500K/BD contains a
500 foot spool of 14 gauge copper stranded wire with black PVC insulation, 20 Terminal Lugs and
100 Steel or Biodegradable Lawn Staples. The DXE-RADW-1000K/BD Radial Wire Kit contains
a 1,000 foot spool of 14 gauge copper stranded wire with black PVC insulation, 40 Terminal Lugs
and 200 Steel or Biodegradable Lawn Staples. RADW-20RT, -32RT or -65RT contain 20 each
radial wires with 1/4" terminal attached. These kits come in 20 Ft, 32 Ft or 65 Ft lengths.
Depending on the number of radial wires used, space them out evenly around the Radial Plate. The
Radial Plate will accommodate up to 60 radial wires (60 laser drilled holes), or up to 120 radials if
doubled up.
Radial Wire Pattern
Radial Wire Hardware Installation

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Overall Pivot Base (US Patent No. 8,130,168) Assembly Drawing
The exploded view drawing is for reference and shows the overall Pivot Base Assembly.

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Pivot Base and Lower Antenna Assembly
1. Locate the heavy duty Extren® insulated channel.
There are 12 holes drilled in the insulated channel.
The top of the insulated channel is identified by two
holes located very near the top side.
2. Locate the stainless steel bottom hinge plate, backing plate, four carriage bolts, four 3/8" flat
washers, four 3/8" split lock washers and four 3/8" hex nuts. Assemble the bottom hinge to the
bottom of the heavy duty insulated channel as shown below.
3. Locate the stainless steel pivot base locking plate, backing plate, four carriage bolts, four 3/8"
flat washers, four 3/8" split lock washers and four 3/8" hex nuts. Assemble the pivot base
locking plate to the top of the heavy duty insulated channel as shown below.

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4. Locate the stainless steel base side bottom hinge, two 1/2-13 x 1-1/4" long stainless steel hex
head bolts, two pivot bushings, four 1/2" x 1/4" stainless steel flat washers, two 1/2" stainless
steel split lock washers, and two 1/2-13 stainless steel hex nuts. Assemble the base side hinge
plate to the bottom hinge plate as shown below.
5. Locate two V-Saddle blocks, two stainless steel V-Bolts, four stainless steel 3/8" flat washers,
four stainless steel 3/8" split lock washers and four stainless steel 3/8-16 hex head nuts. Loosely
assemble (one or two threads beyond the end of the hex nuts) the two V-Bolts to the stainless
steel base side bottom hinge as shown below. The V-Bolts will be tightened in a later assembly
step.

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6. Locate the stainless steel Pivot Base Winch Mount, two stainless steel Pivot Base Plate
Brackets, four 3/8-16 x 1-1/4" long stainless steel hex bolts, eight stainless steel 3/8" flat
washers, four stainless steel 3/8" split lock washers and four stainless steel 3/8-16 hex nuts.
Assemble the Pivot Base Plate Brackets to the Pivot Base Winch Mount as shown below.
7. Locate four 3/8-16 x 1-1/4" long stainless steel hex bolts, eight stainless steel 3/8" flat washers,
four stainless steel 3/8" split lock washers and four stainless steel 3/8-16 hex nuts. Mount the
Pivot Base Winch Mount assembly to the stainless steel Pivot Base Locking Plate.
Note: These four bolts are removed when using the pivoting function as described later on in
this manual.

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8. Locate two V-Saddle blocks, two stainless steel V-Bolts, four stainless steel 3/8" flat washers,
four stainless steel 3/8" split lock washers and four stainless steel 3/8-16 hex head nuts. Loosely
assemble (one or two threads beyond the end of the hex nuts) the two V-Bolts to the stainless
steel Pivot Base Winch Mount as shown below. The V-Bolts will be tightened in a later
assembly step.
9. Locate two thick stainless steel Backing Plates, two thin stainless steel Backing Plates, two
U-Bolt Saddle blocks, two stainless steel U-Bolts, four stainless steel 3/8" flat washers, four
stainless steel 3/8" split lock washers and four stainless steel 3/8-16 hex head nuts.
The two Thick Backing Plates are located next to the U-Bolt Saddles on the inside of the
insulated channel. The two Thin Backing Plates are used on the rear side of the insulated
channel.
Top of Insulated Channel Back and Front views showing the U-Bolt located
Showing U-Bolt installed at the Bottom of the Insulated Channel
The Thick Spacer is on the front side The Thick Spacer is on the front side, the
The Thin Spacer is on the rear side Thin Spacer is on the rear side
Loosely assemble (one or two threads beyond the end of the hex nuts) the two U-Bolts and
associated hardware to the insulated mounting channel as shown above. The U-Bolts will be
tightened in a later assembly step.

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10. Move the four V-Bolts out as far as they will go (these were put on loosely in steps 2 and 8).
Slide the entire assembly onto your mounting pipe. You want approximately 1 inch clearance
from the top of your mounting pipe to the bottom side of the winch mounting plate.
Position the base fixture in the position you pre-selected for the pivoting direction.
Tighten the V-Bolt clamp hardware evenly so the length of the exposed threads is
approximately equal. Any clamp should be tightened evenly from side-to-side with an equal
amount of thread above each nut.

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11. Locate the 3" OD x 72", .120 wall thickness antenna bottom element
section. There are 5 holes drilled in this element section.
One drilled hole at the bottom is for the feedpoint hardware.
Four drilled holes at the top are used for mating to the next antenna
element section.
Loosen the previously installed U-Bolts (Step 9). Insert the 72"
Antenna Bottom Element Section into the antenna base section
through the upper and lower U-Bolts.
Position the single feedpoint hole at the bottom facing outward
as shown in the picture to the right.
The bottom of the 3" OD element tube should be even with the
bottom of the insulated channel as shown below.
Side View Front View
Tighten the lower and upper U-Bolt clamps hardware evenly so the length of the exposed
threads is approximately equal. Any clamp should be tightened evenly from side-to-side with an
equal amount of thread above each nut.

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12. Locate the stainless steel Antenna Hook Mounting Plate, two U-Bolt Saddle blocks, two
stainless steel U-Bolts, four stainless steel 3/8" flat washers, four stainless steel 3/8" split lock
washers and four stainless steel 3/8"-16 hex head nuts.
Loosely assemble (one or two threads beyond the end of the hex nuts) the two U-Bolts and
associated hardware to the antenna hook mounting plate as shown below. The U-Bolts will be
tightened in the next assembly step.
13. Loosen the U-Bolts enough to slide the Antenna Hook Mount assembly over the 3" OD antenna
lower element on the base assembly. Position the antenna hook mount approximately 1/2" above
the insulated channel as shown below.

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14. Tighten the two U-Bolt clamps hardware evenly so the length of the exposed threads is
approximately equal. Any clamp should be tightened evenly from side-to-side with an equal
amount of thread above each nut.
15. Locate the 1/4"-20 x 1" long stainless steel hex bolt, three 1/4" stainless steel external tooth lock
washers, two 1/4" stainless steel flat washers and two 1/4"-20 stainless steel hex nuts. Install the
feedpoint hardware at the bottom of the 3" OD bottom element in the pre-drilled hole as shown
below.
Views showing the Feedpoint hardware installed

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Mounting and using the Optional DXE-VRW-1 Manual Winch
1. Follow the instructions included with the optional DXE-VRW-1 - Manual Winch Add-On Kit
to prepare the Manual Winch for installation on the antenna base assembly.
2. Included with optional DXE-VRW-1 - Manual Winch Add-On Kit is the stainless steel
hardware for mounting the winch on the pivot base assembly. The hardware includes three 3/8-
16 x 1" long stainless steel hex bolts, six stainless steel 3/8-16 flat washers and three 3/8-16
Stainless Steel Nyloc Nuts.
Loosely install the three sets of stainless steel hardware on the manual winch as shown below.
The hardware does not have to be removed from the manual winch to either install or remove
the manual winch from the winch mounting plate.

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There are three holes with slots in the mounting bracket. The flat washers will fit through the
large holes. Once in place, push the winch inward (toward the antenna elements) allowing the
three bolts to go into the three slots. Tighten the hardware to hold the winch in place.
Connect the Hook from the manual winch strap to the Antenna Hook Mount as shown below.
To remove the winch, simply reverse this sequence.