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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 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.
