Dual Vertical Phased Array
DXE-DVA-B
DXE-DVA-160B-P - Dual Vertical Array system for 160 meters
DXE-DVA-80B-P - Dual Vertical Array system for 80 meters
DXE-DVA-60B-P - Dual Vertical Array system for 60 meters
DXE-DVA-40B-P - Dual Vertical Array system for 40 meters
DXE-DVA-30B-P - Dual Vertical Array system for 30 meters
DXE-DVA-20B-P - Dual Vertical Array system for 20 meters
DXE-DVA-17B-P - Dual Vertical Array system for 17 meters
DXE-DVA-15B-P - Dual Vertical Array system for 15 meters
DXE-DVA-12B-P - Dual Vertical Array system for 12 meters
DXE-DVA-10B-P - Dual Vertical Array system for 10 meters
DXE-DVA-B-INS Revision 1b
© DX Engineering 2021
1200 Southeast Ave. - Tallmadge, OH 44278 USA
Phone: (800) 777-0703 ∙ Tech Support and International: (330) 572-3200
Fax: (330) 572-3279 ∙ E-mail: DXEngineering@DXEngineering.com
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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 monoband 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 10 system models available that cover 160 through 10 meters:
Part Number
Band
Phasing Relay Unit and Control Console
DXE-DVA-160B-P
160 meters
DXE-DVA-80B-P
80 meters
DXE-DVA-60B-P
60 meters
DXE-DVA-40B-P
40 meters
DXE-DVA-30B-P
30 meters
DXE-DVA-20B-P
20 meters
DXE-DVA-17B-P
17 meters
DXE-DVA-15B-P
15 meters
DXE-DVA-12B-P
12 meters
DXE-DVA-10B-P
10 meters
The Phasing Relay Unit can be ordered without the DVA Control Console for each band:
Part Number
Band
Phasing Relay Unit
DXE-DVA-160B
160 meters
DXE-DVA-80B
80 meters
DXE-DVA-60B
60 meters
DXE-DVA-40B
40 meters
DXE-DVA-30B
30 meters
DXE-DVA-20B
20 meters
DXE-DVA-17B
17 meters
DXE-DVA-15B
15 meters
DXE-DVA-12B
12 meters
DXE-DVA-10B
10 meters
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.
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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 ground mounted vertical antennas must be resonant in the desired band of operation. Each
vertical element must be directly fed through 1/4-wave long 75Ω transmission 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.
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.
DX Engineering 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 ground mounted 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)
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Can be built with ground mounted 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 the 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 by DX Engineering
Parts Included
DVA Dual Vertical Array Phasing Relay Unit for band specified.
DXE-SSVC-2P Stainless Steel V-Clamp for mounting the 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 DVA Systems
Two identical Full Size, Ground Mounted, Quarter-wave, Monoband, Vertical Antenna
Elements
JTL-12555 - Jet-Lube SS-30 Anti-Oxidant for the vertical antenna elements & hardware
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 Plate - one for each ground mounted vertical element
DXE-UHF-FDFB-KIT SecureMount™ Bulkhead Connector for a clean and quality
feedline connection, 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 PVC jacket
Galvanized Mounting Pipe, 1 inch OD 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)
3M Temflex Tape and 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
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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.
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 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 ground mounted monoband
verticals.
The 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: JTL-12555 Jet-Lube SS-30 Anti-Seize must 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
ground mounted 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 ground mounted 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 ground mounted 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 ground mounted,
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.
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
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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.
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-tonoise 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.
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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 ground
mounted verticals.
BAND
Part Number
Description
Comments
160
DXE-160VA-1
Vertical, 160 meters, 160m, 5,000 W, Pivoting Fixture Mount, 55.00
ft. Height, Kit
Need two
80
DXE-7580FS-VA-1
80 Meter Quarter-Wave Vertical, 80m, Full Size, 68 ft. Height,
5 kW, Stainless Steel Tilt Base, Kit
Need two
DXE-7580FS-VA-2
80 Meter QW Vertical, 80m, Self-Supporting Heavy-Duty,
Full Size, 68 ft., 5 kW, HD Pivoting Base, Kit
Need two
DXE-7580FS-VA-3
80 M QW Vertical, 80m, Self-Supporting Heavy-Duty PLUS, Full
Size 68 ft., 5 kW, HD Pivoting Base, Kit
Need two
60
DXE-7580FS-VA-1
80 Meter Quarter-Wave Vertical, 80m, Full Size, 68 ft. Height,
5 kW, Stainless Steel Tilt Base, Kit
Need two. Shorten overall
length for 60 meters
40
COM-40VA-2P
Vertical, HF, Monoband, Adjustable, 3000 W, 40 meters,
Non-tilt Bracket Mount, 34.3 ft Height, Pair
30
COM-30VA-2P
Vertical, HF, Monoband, Adjustable, 3,000 W, 30 meters,
Non-tilt Bracket Mount, 24 ft Height, Pair
20
COM-20VA-2P
Vertical, HF, Monoband, Adjustable, 3,000 W, 20 meters,
Non-tilt Bracket Mount, 17.0 ft. Height, Pair
17
COM-20VA-2P
Vertical, HF, Monoband, Adjustable, 3,000 W, 20 meters,
Non-tilt Bracket Mount, 17.0 ft. Height, Pair
Shorten overall length for
band desired.
15
12
10
Guying is always recommended for vertical antennas, especially in windy environmental conditions.
Please visit www.DXEngineering.com for details on the vertical antennas listed above.
The Dual Monoband Vertical Antenna Layout
The two full size quarter-wave ground mounted 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-toback 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 ARRL Band Plan for the United States:
Band
(Meters)
Typical Center
Frequency (MHz)
Distance between antennas (1/4-
wavelength - free space)
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
60
5.357
14.0
45.9
IDEAL 60 M
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
30
10.125
7.4
24.3
IDEAL 30 M
20
14.050
5.33
17.5
14.150
5.30
17.4
IDEAL 20 M
14.225
5.27
17.3
17
18.120
4.15
13.6
IDEAL 17 M
15
21.075
3.57
11.7
21.200
3.54
11.6
IDEAL 15 M
12
24.940
3.02
9.9
IDEAL 12 M
10
28.075
2.69
8.8 28.400
2.65
8.7
IDEAL 10 M
29.000
2.59
8.5
Typical Dual Phase Vertical Ground Mounted Antenna Spacing
(Use the formula 246/Center Frequency in MHz for exact distances in feet)
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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 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 reradiated noise into the system. This becomes apparent as reduced front-to-rear
directivity in one or more directions or a higher noise level.
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-FDFB-KIT SecureMount™ 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 ground mounted 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-FDFB-KIT SecureMount™ Bulkhead
Connector and DXE-FP-WIRE-P Feedpoint Wire and Connector Assembly
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The optional SecureMount™ DXE-FDFB-KIT is a hi-quality bulkhead connector with silver
plated outer and inner conductors and PTFE insulation. The connector has
very low loss and high electrical break down. It comes with the hardware to
secure it to the DX Engineering Radial Plate and ensures the radial ground
system, antenna ground and the feedline shield are common. The optional
DXE-FP-WIRE-P Feedpoint Wire Connector Assembly is a perfect
solution to connect the feedline to the vertical element. Don't forget to
weatherproof the PL-259 coaxial connections.
At a minimum, 30 radials, each 1/4-wavelength long
on the array frequency should be used. Arrays using
40 to 60 radials are preferred and highly
recommended. If you have very rocky or mostly
sandy soil, using more longer radials may help the
performance of your phased antenna system. Extra
radials help overcome unknown poor-soil conditions,
improve efficiency, and ensure the best performance.
DXE-RADW Radial Wire, a stranded 14 gauge PVC
insulated copper wire is suggested for the best
results. The 1/4-wavelength wire radials should
placed as symmetrically as possible straight from the
feedpoint around each of the ground mounted
vertical antennas that are spaced 1/-4 wavelength
apart and spaced evenly, regardless of how many
radials are used.
Where the radial wires from one antenna cross the radials of the other antenna, cut the wires and
bond them to a common wire or copper strap as shown. If you have limited space, put in as many
straight radials as you can. The radials must be connected to the shield of the respective feedlines.
DXE-RADP-3 Stainless Steel Radial Plates are the ideal optional items which provide an excellent
system for attaching radial wires to your vertical antenna system feedpoints.
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 they will be virtually impossible to
see or cause trouble. An article describing this process is available the DX Engineering website
www.dxengineering.com 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.
Where the radial wires from one vertical element cross the radials of the other vertical element, they
should be cut and bonded (soldered) together using the optional GCL-1120-050 Copper Radial
Cross Bonding Strap.
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Vertical Antenna Information
Each full size quarter-wave vertical antenna should be resonant (reactance = 0) at the target
frequency for the particular band: 7.150 MHz on 40 meters for example. When the measurement is
being done on one vertical antenna, the other vertical antenna should be floating (not connected to
anything).
It is also expected that the impedance of a single full size quarter-wave vertical antenna should be
close to 39 ohms at resonance, as in 39 + j 0 ohms. That represents the 36 ohms of a "textbook"
quarter-wave vertical antenna, and a few ohms of ground loss, assuming a good ground.
When measured, one vertical with the other one floating, and the results are approximately 39 + j 0
ohms of impedance and then go to the second vertical with the first antenna now floating and again
measure 39 + j 0 ohms, that's a good indication of being ready to go.
Phasing Relay Unit Mounting Pipe
Use a customer supplied thick-walled galvanized steel mounting pipe 36
inches to 66 inches long. This will allow approximately 12 to 18 inches
below ground and approximately 24 to 48 inches above ground. The height
above ground is to allow easy access to the connection on the Phasing
Relay Unit. A thick-walled steel pipe 1-3/4" OD to 2" OD maximum is
recommended with a minimum thickness of 1/8" (1/4" preferred) should be
used. The standard 1-1/2" galvanized water pipe (with a 1.9" OD) is just
fine for this application and can usually be found at your local home
building supply store. For permanent mounting, use a post-hole digger to
make the hole deep enough to accommodate the mounting pipe and a
couple inches of gravel at the bottom for drainage. Set the pipe on the
gravel, use the pre-mix concrete to fill around the pipe, adding water and
mixing as you fill or mix the concrete first, then pour in the hole. Fill the
hole until the concrete is level with the ground around it. Use a level as you
fill the hole to be sure the pipe is straight. Allow to set overnight. Your
location, landscape and ground conditions may require different mounting
solutions in order to have the mounting pipe in a secure position. Your
ground/soil/rocky conditions may require additional mounting pipe length
or method of securing.
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.
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Installing the DVA Phasing Relay Unit to the Mounting Pipe
Using the included DXE-SSVC-2P Stainless Steel V-Clamp mount the DVA Phasing Relay Unit to
the previously installed mounting pipe as shown. The use of JTL-12555 Jet-Lube SS-30 Anti-Seize
for stainless steel hardware must be used for any stainless steel bolts and nuts to avoid galling or
seizing of the stainless steel hardware.
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Dual Vertical Array Control Console
The DXE-EC-DVA is the 3 position controller used to control the DX Engineering Dual Vertical
Array systems (DXE-DVA series).
The DXE-EC-DVA offers the following features:
Stainless Steel Housing
Non-Skid feet
On-Off toggle switch
Three green LEDs indicate position chosen
White blocks to mark your chosen directions
Internal automatic resettable fuse
Includes a 2.1 mm power plug for +12 to +13.8 Vdc power connection
Front and Rear Panels
On/Off toggle switch Control Wire Feed Through
Three Green LEDs Power Connection
3 Position Rotary Switch
The DC Input used is +12 to +13.8 Vdc. A 2.1 mm power cord is supplied with unit. The wire with
the white stripes is the +12 to +13.8 Vdc.
Outer Connection is GROUND, Center Pin is +12 to +13.8 VDC.
If station power is used, it must be well filtered, +12 to +13.8 Vdc at 1 amp (fused) minimum.
Tools Required
Phillips Head Screwdriver
Wire Stripper
Small Flat Blade Screwdriver
Control Console Overall Size
- 15 -
Interior Connections
1. Open the unit by removing the four (two per side) Phillips head screws to remove the cover.
2. Push the end of the cable through the control wire feed
through on the rear of the unit.
3. Three wire connections for the wire are made on the green
header (G-1-2). Terminal 3 is not used. Loosen each
terminal screw until it is near flush with the top of the
connector block as shown to the right.
4. Strip approximately 1/4" insulation from the four conductor
wire ends.
5. Connect each wire to a terminal (G-1-2) by sliding the wire completely into the wire connection
hole. Using a small flat blade screwdriver, tighten the associated screw until the wire is firmly
gripped in place as shown below. Terminal 3 is not used.
Take caution to ensure just the wire is clamped in place, not the wire's insulation which would cause
an open or intermittent connection. Do not over tighten the screw so much that the wire is cut
instead of being firmly gripped. Use the included Ty-Wrap on the inside of the unit to hold the cable
from pulling outward as shown above.
COM-CW3 three wire control cable is a high-quality, PVC-jacketed control cable
consisting of three 20 AWG stranded copper conductors. Your color code may vary.
When connecting the control cable to the DX Engineering Dual Vertical Array system, ensure your
cable is wired the same way at both ends to avoid un-necessary troubleshooting (G to G, 1 to 1 and
2 to 2). Use the chart (below) to record which color wire is connected to each terminal connection.
Connector Wire Reference Chart
G 1 2
- 16 -
The selected position will supply the correct BCD logic voltage as shown in the chart below.
H = +12 Vdc output. Note that with no power, the default selection is Broadside.
Switch Position
OUTPUT
1
2
1
H BROADSIDE
2
H
The DVA Phasing Relay Unit uses a removable five terminal connector plug as shown below. The
DVA connections are labeled “G 1 2 3 G”. The terminals inside the DXE-EC-DVA Control
Console use the same connection letters and are connected G to G, 1 to 1 and 2 to 2.
Number 3 is not used and the second G is tied to the first G internally.
On the DVA Phasing Relay Unit the 5 pin green connector is a two part connector as shown below.
The top part of the connector can be removed by pulling it straight off. This will allow easy wire
replacement or servicing as needed. When pushing the removable connector back in place, ensure
you press straight inward to fully seat the connection.
Phasing Relay Unit Green Connector
Three wire connections for the wire are made on the removable green header (G-1-2). Number 3 is
not used and the second G is tied to the first G internally. Loosen each terminal screw until it is near
flush with the top of the connector block.
Strip approximately 1/4" insulation from the three conductor wire ends to be used.
Connect each wire to a terminal (G-1-2) by sliding the wire completely into the wire connection
hole. Refer to your color code chart to ensure the connections are 1 to 1, 2 to 2 and G to G. Using a
small flat blade screwdriver, tighten the associated screw until the wire is firmly gripped in place as
shown above.
- 17 -
Station Feedline
The weakest link in an antenna system is often the
coaxial cable connections. All connections must be
high quality and weather tight to prevent
contamination and corrosion, which can cause the
feedline impedance to change. This can affect the
signal-to-noise ratio and the directivity of the array.
If the coaxial cable is compromised the shield will
then pick up unwanted signals. This is why the
shield connections are most critical.
The feedline from the Transmitter to the DVA
Phasing Relay Unit must be good quality 50 Ω
coaxial cable such as the DXE-400MAX or DXE-
213U Coaxial Cable. See the DX Engineering web
site for details on the coaxial cable and cable
assemblies available from DX Engineering.
Vertical Element Feedlines
From the DVA Phasing Relay Unit to each antenna element, use good quality
75 Ω coaxial cable cut the proper electrical length for the center frequency
being used. The two feedlines from the DXE-DVA Phasing Relay Unit to the
two vertical elements must all be the same electrical
length, velocity factor and type. Note the orientation
and numbering of the elements. Be sure the appropriate
antenna element is connected to the proper ANT
connector on the DVA Phasing Relay Unit. Additional
weatherproofing protection can be provided when using
weatherproofing tapes available from DX Engineering.
Phasing Unit Dimensions
Lightning Protection
The key to lightning survival is to properly ground feedlines and equipment and to maintain the
integrity of shield connections. Use lightning surge protectors for the coax feedline and control lines
for the array feedline at the station end ground. A proper installation improves lightning protection
and enhances weak signal receiving performance. Consult lightning protection and station
grounding information in the ARRL handbooks, or by referring to the NEC (National Electric
Code). The DX Engineering website has technical and product information listed under “Lightning
Protection and Grounding” on the DX Engineering web site.
- 18 -
Typical EZNEC DX Engineering Dual Vertical Array Plots
- 19 -
Troubleshooting
There are several possible causes for a malfunction. Testing the system is not difficult. Directional switching
and antenna phasing can each be affected by a variety of cabling, connection and or component problems. If
you are troubleshooting a new system check that the wiring from the Control Console to the Array Relay
Unit is correct and no damage has been done to the lines.
Here are the most common causes of malfunction, especially in a system that was previously functioning
properly:
START
80% of all malfunctions are caused by
A, B
or C
A
Broken/Shorted
Conductors
Animals, Chewed,
Punctured, Stretched,
or Broken
Green Connector may have
broken wire or is tightened
against insulation - not bare wire
B
PL-259 is loose
Check all connectors
They may be loose.
C
Shorted/Open
conductors due to
water
Check feedlines and
control cable.
D
RF overload
Make sure antennas are at least 1/2wavelength, on the lowest frequency,
away from any other transmit
antennas.
E
Damaged due to
lightning
Rare, but it can happen.
F
Damaged by animals
or insects
Animals and insects have been known
to relieve themselves on and in the
relay unit and their urine will corrode
and damage electronics
Insects getting inside the unit and
shorting out electronics
A) Broken and/or shorted conductors due to animal, weather or other damage, including chewed,
punctured, stretched and broken control and power lines and/or feedlines for the system and each
antenna. Also, screws in the green removable connector at the DVA Phasing Relay Unit can
inadvertently be tightened onto the insulation of control or power conductors.
B) Loose PL-259 connector causing disengagement from the female pin of the SO-239 connector. This can
happen on feedlines to/from the vertical elements and the DVA Phasing Relay Unit as well as the main
feedline from DVA Phasing Relay Unit to the transceiver.
C) Shorted or opened conductors caused by water migration into a control line or a feedline.
Over 80% of all phased array malfunctions have been caused by the above system problems. A
thorough inspection and subsequent testing of each control cable, RF cable, and their respective
connections, will uncover the cause of most phased array system troubles.
- 20 -
Here are a few other causes for malfunction:
1) Damaged Dual Vertical Array Relay unit due to lightning. This has been reported only a
couple of times and is not very likely.
2) Dual Vertical Array Relay units that were damaged by animals or insects.
If necessary, the following further troubleshooting procedure may assist in finding the malfunction.
Advanced Troubleshooting Procedure
1) Test the DXE-EC-DVA Dual Vertical Array (DVA) Control Console unit, which should be connected
only to the control lines of the Dual Vertical Relay Unit. When the DVA Control Console is connected
to the control cable, do all three of the selected switch position LEDs light normally when rotating the
directional control knob?
2) When rotating DVA Control Console switch from position 1, Broadside and 2, if all three LEDs light
normally, measure BCD output voltages. Nominally +12 Vdc. Connections A and B, reference to the
ground pin G as shown below. The selected position will supply the BCD logic voltage as shown in the
chart below.
Switch Position
G 1 2
1
GND
H
0
BROADSIDE
GND
0 0 2
GND
0
H
Output Truth Table - “H” Equals +12 Vdc
3) If the voltages are not normal, less than +10 to +18 Vdc, with the control line connected, then
disconnect the control line and retest DVA Control Console. If voltages that were not correct, are now
okay, that indicates a short in the control line or a problem in or beyond the Phasing Relay Unit.
4) If the DVA Control Console has only a one or two LEDs lighting up with the control cable
disconnected, then it may have sustained lightning pulse damage and will need to be repaired or
replaced. A new DVA Control Console (DXE-EC-DVA) is available from DX Engineering.
Continue troubleshooting the array control with a good DVA Control Console or by using a 1A fused
power source.
5) Determine if the control line is intact by resistance or voltage testing each conductor for shorts with the
far end of the control cable disconnected from the DVA Phasing Relay Unit.
6) With a good DVA Control Console or other power source connected, measure 1 and 2 control
conductor voltages at the Phasing Relay Unit with the control cable connected, and again at the end of
the control cable that is disconnected from the Phasing Relay Unit. If measured voltages are not
between +10 to +18 Vdc on the selected line, a resistive, short or open circuit problem exists in the
control line or in the Phasing Relay Unit. Normal voltages on the connected control line will cause
relays to switch inside the Phasing Relay Unit. If switching voltages are correct, lack of system
directivity may be due to antenna feedline(s) or the vertical elements.
7) Test reception of each ground mounted Vertical Antenna by connecting each antenna feedline, one at a
time, to an activated port on the Phasing Relay Unit. This assumes that a good port has been identified
and is functioning properly. Normal reception must be confirmed from each antenna. If one or both
monoband verticals produce a low or no signal, then vertical elements, connections or feedlines may
need to be serviced or replaced.
8) If both ground mounted vertical elements tested provide the same signal level in one port, then change
switching to select the other port and try each antenna on that port one at a time, testing for the same
level of reception. If one or two of the antenna ports are dead or has diminished reception, there may be
a problem in the Phasing Relay Unit.
- 21 -
At this point, the problem in your system should have been identified.
If you need additional assistance from DX Engineering, feel free to call or write. Detailed discussions of
system function, connections, and troubleshooting is best handled by telephone, Monday through Friday,
8:30 am to 4:30 pm Eastern Time, at 330-572-3200.
Testing the Ground Mounted Vertical Antennas without the DVA connected
This test will determine if the ground mounted vertical antenna system needs to be adjusted.
If the test results are not correct as described, one or both of the vertical antennas (or feedlines) may need to
be adjusted accordingly.
If the test results are correct as described, there may be a problem with the Dual Vertical Array Relay Unit.
It is assumed that the full size quarter-wave ground mounted vertical antennas are resonant (at the
chosen frequency), are identical and properly installed. The radial system for both antennas must be
complete and the quarter-wave feedline coaxial cables are electrically cut to the proper length for the
frequency desired.
Parts needed:
DXE-533-2 - UHF-T Adapter
Antenna Analyzer or VNA: Rig Expert Antenna Analyzers are a good quality choice
Testing the Ground Mounted Vertical Antennas without the DXE-DVA connected
Each full size quarter-wave ground mounted vertical antenna should be resonant (reactance = 0) at the target
frequency for the particular band: 7.150 MHz on 40 meters for example.
When the measurement is being done on one vertical antenna, the other vertical antenna should be floating
(not connected to anything).
It is also expected that the impedance of a single full size quarter-wave vertical antenna should be close to 39
ohms at resonance, as in 39 + j 0 ohms. That represents the 36 ohms of a "textbook" quarter-wave vertical
antenna, and a few ohms of ground loss, assuming a good ground.
When measured, one vertical with the other one floating, and the results are approximately 39 + j 0 ohms of
impedance and then go to the second vertical with the first antenna now floating and again measure 39 + j 0
ohms, that's a good indication of being ready to go.
Now the pair of vertical can be tested together.
The 75 ohm 1/4-wavelength feedlines from the two vertical antennas
are connected to a UHF-T (DXE-533-2) which is connected directly to
an Antenna Analyzer or VNA.
Do not use any extra coaxial cables since we are trying to measure
the impedance right at the junction.
The measured impedance at the target frequency should be very close
to: 46 + j 12 ohms (in this example, the target frequency is 7.150
MHz). The values should be within a few ohms. Values that are far off
may indicate a problem with one or both of the vertical antennas, cables
or installation. If this occurs, then each antenna and cable should be
carefully measured by themselves and adjustments made accordingly.
- 22 -
The following is a graph showing the impedance and reactance curves with the selected frequency
of 7.150 MHz with the two antennas connected as shown.
The green arrows point to the readings (46 + j 12 ohms) at the selected 7.150 MHz.
The SWR of 1.3 is not the SWR dip. This is the expected value at the target frequency regardless of
the band. The SWR dip well above array selected frequency is normal. Remember, the goal is 46
n+ j 12 ohms at the desired frequency.
The following graph shows the SWR sweep of the array connected as instructed.
The sweep shows the SWR dip above the selected frequency of 7.150 MHz.
Even though the SWR dip is high in frequency, the impedance (46 + j 12 ohms) is right on target at
the selected frequency of 7.150 MHz. Do not adjust the verticals for a different result when the
antenna feedlines are connected in parallel for this test.
- 23 -
The values should be within a few ohms. Values that are far off may indicate a problem with one or
both of the vertical antennas or installation. If this occurs, then each antenna should be carefully
measured by themselves and adjustments made to achieve the 39+ j 0 ohms at each antenna
feedpoint.
The bottom line: If you measure an impedance of 46 + 12 j ohms using this T-adapter paralleled
phasing feedline test set up with both vertical antennas, your system is good and ready to connect to
the Dual Vertical Array.
NOTES:
- 24 -
Technical Support
If you have questions about this product, or if you experience difficulties during the installation,
contact DX Engineering at (330) 572-3200. You can also e-mail us at:
DXEngineering@DXEngineering.com
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 2021
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.
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