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Computer programs have been developed to calculate the radiation patterns and gain for the following types of antennas, as used by administrations, for HF broadcasting and other services: arrays of half-wave horizontal dipoles; quadrant antennas and horizontal dipoles; log-periodic antennas; tropical antennas; rhombic antennas and vertical ...
Antennas 101 3 The Basics - 2 •The orientation of the E-field determines the polarization of the wave because that’s what makes the electrons move (current) •Antennas transmit & receive radio waves in the same way •The radiation pattern shows how antennas distribute energy in space 2013
THE HAND-HELD RADIO ANTENNA DILEMMA – 4 – •Adding appropriate lengths of radial material at the base of the antenna provides a ground plane for improved radiation pattern and counterpoise for known RF current return path. (C)2016 - NO1PC, JIM ASPINWALL
antenna is not good if it does not radiate enough signal or if it sends the signal off in the wrong direction. Our purpose here is to discuss only those features of radio wave transmission that have some bearing on the installation and maintenance of a high-frequency (HF) antenna system. B. Wavelength and Frequency
Shortened HF Helical antennas have been used by radio amateurs in activity on the Air during a long time. For example, shortened vertical helical antennas have been used in hand held CB radio stations (it is 11- meter HF band) from the 50- years of the 20- century.
NOTE 1 – Part 1 to Annex 1 gives comprehensive and detailed information on the theoretical characteristics of HF transmitting antennas. Computer programs have been developed from the theory to calculate the radiation patterns and gain for the various included antenna types.
Radiation patterns on 80, 60, and 40 meters would provide near vertical incidence skywave (NVIS) propa-gation. Low-angle radiation was calculated for 15 and 10 meters. Patterns on 6 meters were multi-lobed, using the seventh harmonic on the 40-meter wire. Figure 1 — The coupled-resonator HF antenna design. QS2304-Taft01 16-foot single wire
