TC 9-64 _________________________________________________________________________
A half-wave antenna (Hertz) consists of two lengths of rod or tubing, each a
quarter-wavelength long at a certain frequency, that radiate a doughnut
pattern.
Figure 4-Sum 7. Half-Wave Antenna Pattern
A quarter-wave antenna (Marconi) is a half-wave antenna cut in half with
one end grounded. The ground furnishes the missing half of the antenna.
Figure 4-Sum 8. Quarter-Wave Antenna
The ground screen and the counterpoise are used to reduce losses caused by
the ground in the immediate vicinity of the antenna. The ground screen is
buried below the surface of the earth. The counterpoise is installed above the
ground.
4-62
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