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Radial System
The use of a radial system is a key requirement for any high performance quarter wave vertical
antenna system.
With any vertical antenna system, the radials are the second half of the
antenna. The radials contribute to the radiation efficiency of the entire vertical antenna
system.
The exact number of radials required for low SWR and reasonably efficient operation will depend
in large measure on local earth conductivity, and this may vary considerably from one place to the
next and from one frequency band to the next, especially if your radials are not long enough. For
most installations the soil conditions will be poor to very poor when it comes to conductivity.
The best procedure is to assume that most earth is a poor conductor over the HF range and that
some radial wires will be needed. Radials may be placed on the surface of the earth or buried
slightly below the surface to get them out of the way, and their length is largely a matter of
convenience. In general, a large number of short radials are preferable to a small number of longer
radials for a given amount of wire, especially if fewer than a dozen radials are to be used. Unlike
resonant radials that must be cut to the proper lengths for use with elevated verticals, ground-level
radials need not to be cut to any particular length; their sole purpose is to provide less lossy return
paths for currents flowing along the earth than the earth itself can provide. And, since "return"
currents will be flowing back to the antenna from all points of the compass, the radial wires should
be spaced uniformly over 360 degrees, although physical circumstances will often make this "ideal"
distribution impossible. For a discussion of ground system for elevated verticals, see the section
entitled "Above Ground Installations" following Checkout and Adjustment instructions.
For the best performance on 80 and 40 meters with this antenna,
installing 30 to 60 radials each 65 feet long is highly
recommended. At a minimum, 20 radials each 32 feet long may be
used with this antenna. But, installing many more radials helps
overcome unknown poor soil conditions, improves efficiency and
ensures the best performance possible from this Butternut vertical
antenna. Radial Wire that is 14 gauge stranded copper with black
relaxed PVC insulation wire is suggested for longevity. DXE-
RADW-32RT or 65RT Radial Wire Kits are available.
The wire radials should be placed as symmetrically as possible
straight from the feedpoint around the vertical antenna and spaced
evenly, regardless of how many radials are used. Do not cross or
bunch any radial wires as this nullifies their effectiveness. If you have limited space, put in as many
straight radials as you can. The radials must be connected to the shield of your feedline. A Stainless
Steel Radial Plate is the ideal optional item which provides an excellent system for attaching radial
wires to your vertical antenna system.
Radial wires can be laid on the roots of the grass or on bare ground using
Radial Wire Anchor Pins
to hold them down. Using enough staples will ensure the wires will not be snagged by mowers,
people, or animals. Depending on where you live and the type of grass you have, grass will quickly
overgrow the radials and it will be virtually impossible to see them. An article describing this
