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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.
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.
