DX Engineering DXE-DVA-160-P User manual

Dual Vertical Phased Array
DXE-DVA
DXE-DVA-160-P - Dual Vertical Array system for 160 meters
DXE-DVA-80-P - Dual Vertical Array system for 80 meters
DXE-DVA-40-P - Dual Vertical Array system for 40 meters
DXE-DVA-INS Revision 0b
© DX Engineering 2015
1200 Southeast Ave. - Tallmadge, OH 44278 USA
Phone: [phone] ∙ Tech Support and International: [phone]
Fax: [phone] ∙ E-mail: [email protected]

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Introduction and General Information
Congratulations on your purchase of the DX Engineering Dual Vertical Phased Array System,
custom designed and tested to offer the best directional transmitting and receiving performance in
proportion to the space required. Advanced design, with a stable, clean and low-angle pattern makes
the DX Engineering Dual Vertical Phased Array (DVA) the finest dual element quarter-wave
monoband phased antenna system available. The DX Engineering Dual Vertical Phased Arrays are
advanced vertical antenna phasing systems that set new standards in two vertical element array
performance. DX Engineering Dual Vertical Phased Array system design eliminates the waste load
port of previous hybrid-type two-element systems, thus increasing array efficiency. Each mono-
band Dual Vertical Array system includes a sleek new Phasing Relay Unit and a new Control
Console. The model number of your system corresponds to the band for which it was manufactured.
There are 3 system models available that cover the 160, 80, or 40 meter bands:
DXE-DVA-160-P - Dual Vertical Array - 160 meters - Phasing Relay Unit and Control Console
DXE-DVA-80-P - Dual Vertical Array - 80 meters - Phasing Relay Unit and Control Console
DXE-DVA-40-P - Dual Vertical Array - 40 meters - Phasing Relay Unit and Control Console
The Phasing Relay Unit can be ordered without the DVA Control Console:
DXE-DVA-160 - Dual Vertical Array - 160 meters - Phasing Relay Unit Only
DXE-DVA-80 - Dual Vertical Array - 80 meters - Phasing Relay Unit Only
DXE-DVA-40 - Dual Vertical Array - 40 meters - Phasing Relay Unit Only
The Dual Vertical Array Control Console can be ordered without the DVA Phasing Relay Unit:
DXE-EC-DVA - Control Console only for the Dual Vertical Array System
DX Engineering Dual Vertical Phased Array (DVA) systems produce two enhanced End-Fire
Cardioid patterns and one Broadside-Omni pattern. New heavy-duty components handle 2 kW
continuous RF power with array performance at low SWR over a wide bandwidth. The Dual
Vertical Array end-fire directional patterns achieve a real front-to-back over 20 dB with typical
array forward gain up to 3 dB over a single vertical.
Each DX Engineering Dual Vertical Phased Array’s mono-band weatherproof DVA Phasing Relay
Unit includes a clamp for mounting on a mounting pipe that is positioned directly between two
ground-mounted, full-size, quarter-wave resonant verticals. The antennas must be located as
described in the installation section to provide switchable patterns in desired directions. The
forward lobes are reasonably wide eliminating the need for precise aiming while also providing
coverage of in-between directions.
The proper spacing between these user-supplied antennas is one-quarter wavelength free space, and
each should be installed with 40 or more ground radials; all antenna system parts are also available
from DX Engineering.
The two vertical antennas must be resonant in the desired band of operation. Each vertical element
must be directly fed through 1/4-wave long 75Ωtransmission lines. No additional matching
components or decoupling devices may be used, like baluns or coils, between the centrally located
Dual Vertical Phasing Relay Unit and the verticals, as additional transmission line lengths can
reduce array performance.

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DVA systems require the 75-ohm antenna feed cables to be electrically tuned to one-quarter
wavelength. Offered by DX Engineering as an option, these custom built PL-259 terminated cable
assemblies use the highest quality waterproof polyethylene jacket direct-burial DXE-11U low-loss
foam coax. These custom length coaxial cables are frequency specific, electronically tuned and
connect the DVA Phasing Relay Unit directly to each mono-band vertical antenna feed point and
radial system.
The vertical antennas must be series-fed at the base, 1/4-wave long and must be resonant. DX
Engineering offers vertical antennas that are well suited for this application. Above all, a properly
designed and installed radial system is necessary for maximum system performance.
The included companion DXE-EC-DVA Control Console is a three-position directional pattern
selector that operates on 13.8 Vdc and features a 3-position rotary switch, directional LED
indicators and scratch pads on the console for the user to write in their array end fire directions. The
DXE-EC-DVA Control Consoles require only a 3-conductor 20 AWG cable for connection to the
DVA Phasing Relay Unit.
DXE-DVA - Dual Vertical Array System Features
The Dual Vertical Array System is a monoband two element, three direction-switchable array
based on a two element end-fire/broadside combination of identical vertical elements. This antenna
array system is capable of delivering pattern directional performance superior to other systems in its
class.
Custom design with stable and clean low-angle patterns
No dump power as on other types of phased arrays so all your power goes to the antenna
elements
Power Handling: 2 kW continuous
Directional performance - Two End Fire and one Broadside directions
Forward Gain (approximate as compared to a single vertical): 3 dB End-Fire, 1 dB
Broadside (Omni)
Can be built with monoband verticals to cover any single band
RF Connectors: Three SO-239 (UHF Female): Transmitter, Antenna 1, Antenna 2
Excellent signal-to-noise ratio
Directivity over a very wide frequency range in the band selected
Excellent relay contact reliability
DC powered control console allows system operation without AC power mains
Control Cable: 3 conductors, minimum 20 AWG
Control Wire Connections: Set screw connectors internal at the Control Console and a
removable external connector at the DVA Phasing Relay Unit
Cover on the DVA Phasing Relay Unit made from tough UV protected plastic
Stainless steel chassis and mounting plate on Phasing Relay Unit
DVA Control Console uses +13.8 Vdc input has three LEDs and three position rotary
direction switch (Position 1, Broadside, Position 2)
Designed, manufactured and tested in the USA by DX Engineering

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Parts Included
DXE-DVA Dual Vertical Array Phasing Relay Unit for band specified.
DXE-SSVC-2P Stainless Steel V-Clamp for mounting the DXE-DVA Phasing Relay Unit
to a mounting post between 1" and 2" OD
DXE-EC-DVA Dual Vertical Array Control Console
2.1 mm Power Plug with wires to connect to the station +12 to +13.8 Vdc filtered power
supply
Additional Parts Required, Not Supplied with the DXE-DVA Systems
See the Optional Items at the back of this manual for details
Two identical Full Size Quarter-wave Monoband Vertical Antenna Elements
DXE-P8A - Penetrox A Anti-Oxidant for the vertical antenna elements
DXE-RG-11U Phasing Cables, 75-ohm, cut to the proper electrical length for the applicable
dual vertical array system center frequency
DXE-RADP-3 Radial Plates - one for each vertical element
DXE-363-SST Bulkhead Connectors for a clean and quality feedline connections, one for
each Radial Plate
DXE-FP-WIRE-P Feedpoint Wire & Connector Assemblies, one for each vertical element
DXE- RADW Radial Wire for the required vertical antenna radials
GCL-1120-050 Copper Radial Cross Bonding Strap, 2” wide
COM-CW3- Three Wire Control Cable - COM-CW-3 is 3-wire, 20 AWG, stranded copper
with a grey PVC jacket
Galvanized Mounting Pipe, 1 inch minimum to 2 inches OD maximum, for mounting the
Dual Vertical Array Phasing Relay Unit at the center of the array using the supplied DXE-
SSVC-2P Stainless Steel V-Clamp (see text for details)
UMI-81343 Never-Seez®or DXE-NSBT8 Anti-Seize for stainless steel hardware
DXE-3M2155 3M Temflex Tape and TRM-06132 Scotch Super 33 Tape for
Weatherproofing the coaxial cable connections
DXE-400MAX or DXE-213U or equivalent, 50-ohm coaxial cable for the array main
feedline from the transceiver to the Phasing Relay Unit
Manual Updates
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.

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Tools Required
1/2” nut driver or wrench (for the DXE-SSVC-2P V-Clamp
Wire stripper for control lines
Small flat blade screwdriver for control line connections
Soldering Iron and Solder to join the two radial fields together where they meet
General Installation Information
The DXE-DVA Dual Vertical Array Phasing Relay Unit should be mounted to a customer supplied
mounting pipe at the center of the array, halfway between the two monoband verticals.
The DXE-DVA Dual Vertical Array Phasing Relay Unit has a built-in, stainless steel, pre-drilled
mounting flange to accommodate up to a 2 inch OD mounting pipe. The included DXE-SSVC-2P
Stainless Steel V-Bolt Saddle Clamp is for attaching the Phasing Relay Unit to the customer
supplied 1" to 2" OD mounting pipe. An optional DXE-CAVS-1P V-Bolt Saddle clamp can be
used for pipe from 3/4" to 1-3/4" inches OD. The Phasing Relay Unit can also be mounted on a
sturdy wooden post.
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.
The Array Phasing Relay Unit must be mounted with cover upward and the control and coaxial
cable connections downward to prevent water from entering the box. The stainless steel base of the
Array Phasing Relay Unit has weep holes to allow condensation that may build up inside the unit to
leave. Additional weatherproofing protection may be used on the coaxial connections.
WARNING!
INSTALLATION OF ANY ANTENNAS NEAR POWER LINES IS DANGEROUS
Warning:Do not locate the antennas near overhead power lines or other electric light or power
circuits, or where they can come into contact with such circuits. When installing the antennas, take
extreme care not to come into contact with such circuits, because they may cause serious injury or
death. Make sure when you are digging, you are not near any buried utility lines.

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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.
Installation
Site Selection
Select mounting locations clear from power lines and structures by a minimum of height of the
monoband antennas used plus 10 feet (for the 10 foot safety rule). Consider overhead power lines,
utility cables and wires. The monoband verticals should be mounted away from local noise sources
or other metallic objects which can re-radiate noise and affect the tuning, radiation pattern and
SWR. Determine the direction you want the array positioned. There should also be a clear diameter
from the monoband antennas for the guying and radial systems that will extend away from the
antennas.
Topographical Considerations
Flat or gradually sloped land is best. Erecting the transmitting array on steeply sloped land or
uneven terrain might degrade performance. To avoid pattern degradation, antenna elements should
have reasonably similar elevations. It's recommended the maximum ground height difference
between any of the vertical antennas in the array should be less than 20% of the array diameter. For
example, two 80 meter verticals 66 feet apart should be within 13 feet of level. Every effort should
be taken to make the elements symmetrical. Elements must be similar or identical in construction
and grounding. Elements should be mounted above any standing water, but as close to the ground as
possible. In general, the system will not be affected by trees or foliage so long as the foliage is not
near an element. The open ends or tips of the elements are particularly sensitive to close branches or
foliage. There should be a reasonably clear electrical path for at least 1 wavelength in important
receiving directions. The site should allow a radial system to be as evenly distributed around each of
the vertical elements as possible, although perfect symmetry isn’t important so long as the radial
connections are good.
Most amateur radio operators in the continental United States will want the system to point toward
Europe (NE) as a default (position 1). Therefore the system described in this manual will be laid out
with vertical antenna elements 1 to the Northeast in a line going to antenna 2 toward the Southwest.

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Note: This array, like all dual phased vertical set ups, has a fairly wide flat forward lobe. This
means exact direction headings are generally not critical. We should still remember there is a
difference between True North and Magnetic or Compass North. Without going into all of the
details, you want your system aligned to True North. Depending on your location you can check
your position using various geological, topographical or aviation maps to determine True North.
If your location has more than 10 degrees magnetic declination, you may want to correct for it.
Declinations below ten degrees can be safely ignored.
If you know your longitude and latitude, you can then pinpoint yourself on an aircraft navigation or
geological map. If you don't know your longitude and latitude, you can find that information on
many of the map services available on the internet, or use a GPS.
Site Selection in Relation to Noise Sources
Since the array is generally used for both transmitting and receiving, you should listen to desired
bands and identify any sources of unwanted noise. Elimination of noise sources is required for
optimal receiving results. If noise sources cannot be eliminated, then locate the antenna array as far
away from noise sources as possible.
Since this array is directional, locate the array so the rear of the array is pointing towards the
dominant noise source. This ensures the array has maximum suppression of noise when beaming in
the primary listening direction. For example, if you primarily want to work Europeans from the
eastern USA (Northeast direction), try to position the array so the dominant local noise is Southwest
of the array. There is no advantage at all when an array points into the noise, no matter what the
array gain is.
Gain does not generally matter, only the ratio of signal response to noise response changes S/N
ratio. The only way S/N ratio improves at HF is if the array nulls the noise more than it nulls the
desired signal.
The second-best location for the array is when the noise source is as far as possible to either side of
the array. If you look at patterns, the ideal receiving location for the array is one that places
undesired noise in a deep null area.
If your location doesn’t have the usual noise sources (power lines, electric fences, etc.), locate the
array so that your other transmitting antennas and buildings are off the back or side of the primary
array direction.
Consider these things about noise sources:
If noise is not evenly distributed, performance will depend on the gain difference between
the desired signal direction (azimuth and elevation) and average gain in the direction of
noise.

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If noise predominantly arrives from the direction and angle of desired signals (assuming
polarization of signals and noise are the same) there will be no improvement in the signal-to-
noise ratio.
If the noise originates in the near-field of the antenna, everything becomes unpredictable. This is a
good case for the use of separate receiving antennas placed as far from noise sources (such as power
lines) as possible.
Monoband Antennas for a Dual Vertical Array System
The following are some suggested DX Engineering and COMTEK full size quarter-wave monoband
vertical antennas are an ideal match for top performance in a dual vertical array system. You’ll need
2 verticals. The COM-40VA-2P is a package of two antennas. The other listed antennas are single.
DXE-40VE-1
COM-40VA-2P
DXE-7580FS-VA2
DXE-7580FS-VA3
DXE-ATK65
and
DXE-VE BASE
Band
40
40
80 or 75
80 or 75
80 or 75
Element
Size
Range
2" to 1/2"
2" to 1-3/8"
3” to 1/4”
4” to 1/2”
2" to 7/8"
Height
33-35'
35'
68’
68’
64'
Guying
Suggested
Suggested
Suggested
Suggested
Required
Please visit www.DXEngineering.com for details on these vertical antennas
The Dual Monoband Vertical Antenna Layout
The two full size quarter-wave monoband vertical antennas
making up the dual vertical array system must be properly
positioned. The example on the right shows a typical set up
where antenna 1 is toward the NE and antenna 2 is toward
the SW. You must adhere to the dimensions shown on the
next page for optimum performance. The placement of the
two vertical antennas in relation to each other is somewhat
critical. If the dimensions are more than five percent out of
specification, system performance can suffer.
The formula for determining the distance between each
antenna (1/4-wavelength) is:
246
L in Feet =
▬▬▬
MHz
Use 246 divided by the Frequency in MHz = Length in feet

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Other spacing close to this value may work, but the characteristics of the main lobe will change. For
optimal gain, directivity and front-to-back, time spent in laying out a symmetrical installation will
pay solid dividends. The system is forgiving, but the best front-to-
back is obtained when symmetry is maintained and with each
element resonant on the same frequency and with each antenna
base at the same elevation on flat land. Sloped land installations
should not use one elevated and one ground-mounted antenna.
The plots shown to the right are for a typical 40 meter DXE-DVA
Dual Vertical Phased Array pointing toward Europe (Northeast) is
position number one on the DVA Control Console.
The following chart shows various calculations depending on the
desired center frequency. The frequencies shown here are various
CW, DX, and SSB frequencies used in the American Radio Relay League Band Plan:
Band
(Meters)
Typical
Center
Frequency
(MHz)
Distance between
antennas (1/4-wavelength)
at the Center Frequency
Meters
Feet
160
1.815
41.3
135.5
1.830
40.9
134.4
IDEAL 160 M
1.845
40.6
133.3
1.900
39.5
129.5
80/75
3.550
21.1
69.3
3.575
21.0
68.8
3.650
21.0
67.4
IDEAL 80 M
3.710
20.2
66.3
3.795
20.0
64.8
40
7.040
11.0
34.9
7.110
11.0
34.6
7.150
10.4
34.4
IDEAL 40 M
7.225
10.3
34.0
Typical Dual Phased Vertical Antenna Spacing
(Use the formula 246/Center Frequency in MHz for exact distances in feet)
Performance of the Dual Vertical Array can noticeably decrease if metal structures radiating even
small amounts of noise or signals are within 1/2-wavelength of the array.
Note: The DXE-DVA -Dual Vertical Array system should be separated from transmitting or other
antennas and structures (particularly metal) by at least 1/2- wavelength. Less separation may
cause significant pattern distortion and the introduction of re-radiated noise into the system.
This becomes apparent as reduced front-to-rear directivity in one or more directions or a
higher noise level.

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With so many variables involved, there is no optimum or minimum spacing for effects on pattern.
The best practice is to install the array as far as possible from tall conductors or noise sources, or
place potential problems in less frequently used directions. For best pattern, space the system as far
as possible from conductors that might be noise sources or re-radiate unwanted signals. One
wavelength or more is generally ideal, although adequate performance generally occurring at closer
spacing, with one-half wavelength minimum recommended.
Radial System Information
The use of a radial system is a key requirement for a high performance dual phased monoband
vertical antenna system. With any vertical antenna, the radials are the second half of the antenna.
The radials contribute to the radiation efficiency of the entire phased vertical antenna system.
Using an optional patented DXE-RADP-3 Radial Plate greatly simplifies mounting radial wires in a
vertical installation. The DXE-RADP-3 stainless steel Radial Plate contains enough stainless
hardware sets to attach 20 radials. Additional 20 set radial connection hardware kits DXE-RADP-
HW1K are available from DX Engineering.
DXE-RADW - Radial Wire Kits and Components contain everything you need to make your own
radials, including steel or biodegradable lawn staples to hold the wire down, are also available.
The best way to connect the feedline to the radial plate and vertical feed point is to use an optional
DXE-363-SST bulkhead connector with the DXE-FP-WIRE-P Feedpoint Connection Assembly.
A DXE-SSVC-2P V-Clamp is needed to secure the radial plate to the 2” OD vertical monoband
antenna mounting pipe.
The radial plate must be mounted to the vertical antenna’s mounting pipe prior to installing the
vertical element or antenna. It should be as close to the ground as possible, while still allowing
access to the radial wire hardware for tightening. A one inch ground clearance is adequate.
Optional: DXE-RADP-3 Radial Plate, DXE-363-SST Bulkhead Connector and DXE-FP-
WIRE-P Feedpoint Wire and Connector Assembly
The optional DXE-363-SST is a hi-quality bulkhead connector uses silver plated outer and inner
conductors and PTFE insulation. The connector has very low loss and high electrical break down. It