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T2FD AntennaThe T2FD (tilted, terminated, folded dipole) is a general-purpose shortwave antenna developed in the late 1940s by the United States Navy.
It performs reasonably well (if not with optimal efficiency) over a wide frequency range and without marked dead spots in terms of frequency or direction.
While in many ways measurably inferior to antennas specifically designed for given frequency bands, or optimized for directionality, its all-around performance, relatively modest size, low cost, and the fact that it does not require any electronic matching to operate with a standard shortwave transmitter, have made it popular in professional shortwave communications. Since the late 1980s also amateur radio operators and hobby shortwave listeners have become aware of its qualities.
A typical T2FD is built as follows, out of wire conductors:
For example, an antenna for the lower portion of shortwave (3 - 18 MHz) will be roughly 33m (110 feet) long, with conductors spaced 1m (3.3 feet).
In order to cover the higher portion of shortwave (5 - 30 MHz), this antenna will be roughly 20m (66 feet) long, with a spacing of 60 cm (24 inches).
Many ready made commercial versions are available for the professional / military, ham radio, and hobby listening markets.
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