9
Installation
Suggested Installation Sequence
Site Selection
Antenna Selection
Mounting post installations
Feedline and control cable installation
Radial System Installation
Antenna Installation and tuning
System phasing unit installation
Coaxial Cable and control wire connections
Testing and operation
Site Selection
Select a mounting location clear from power lines, structures and other antennas.
Pay special
attention to overhead power lines, utility cables and wires
. Vertical antennas should be mounted
well away from local noise sources or large metallic objects that might re-radiate noise and affect
the tuning, radiation pattern or SWR. When using the
DX Engineering Tilt Base
, determine the
direction you want the antenna to tilt down and make sure there is adequate clearance. There should
also be a clear area for guying and radial systems extending away from the four antennas.
The Four Square Layout
The four monoband vertical antennas making up the four-square system must be properly
positioned. You must adhere to the dimensions shown in
Table 2
for optimum performance. The
placement of the four vertical antennas in relation to each other is somewhat critical. If 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
For four square arrays use 246 divided by the Frequency in MHz = Length in feet
Other spacing close to this value may work, but the characteristics of the main lobe will change
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.
