For the fm operator living in the primary coverage area of a repeater, the ease of construction and low cost of a 14. This is a quarter wavelength wire that stands above a groundplane. However when it is not possible to ground mount an antenna because of ground conditions or it is necessary to elevate the antenna, another solution is to use a ground plane. The antenna must have enough ground plane to be efficient, and ideally the ground plane should. They include factors such as antenna height versus erp, antenna gain versus transmitter power, vertical plane radiation patterns, brewster angle, fresnel zone, polarization, site. This is the first thing you will need to build a quarter 14. It has stable structure, excellent performance, super good sound quality and is very easy to use. This handbook presents basic propagation theory, the fundamentals concerning. Troubleshooting guide trouble shooting guide audio is distorted.
Pdf in this paper, a wearable patch antenna is designed for frequency modulation radio. The polarization of an antenna refers to the orientation of. Vhf and uhf antenna systems 1821 fig23these drawings illustrate the dimensions for the 144mhz ground plane antenna. Conversions between electric field strength e, magnetic field strength h and power density s. Groundwave propagation involves the transmission of a radio signal along or near.
Ground mounted antennas are often very easy and convenient to use. As the name indicates the antenna ground plane acts as a. Ground plane antennas for 144, 222 and 440mhz for the fm operator living in the primary coverage area of a repeate r, the ease of construction and low cost of a 14. Solder the center coax wire to one of the wires and the ground shield wire to the other. In single element antennas, the 58 wave antenna has the best performance 3 db when mounted on a suitable ground plane. This dropping of the ground plane causes the antenna to radiate its radio. It follows the fm convention of vertical polarization.
Comes with 5 different antennas, with tuning in above frequency sections. Whats the difference between a dipole and a ground plane. Pdf ground plane size reduction in monopole antennas for. Groundplane antennas for 144, 222 and 440 mhz arrl. Make sure the shield wire does not touch the center wire. Pdf in this paper, the design of a ground plane that does not produce drastic. How to make a dipole fm transmitter antenna page 2 center wire from the outer ground shield wire. It is an unbalanced antenna, therefore compatible with coaxial transmission line without requiring a balun. Try adjusting the input level on the side of the fm transmitter. Design of a magnetoelectric dipole antenna for fm radio. The transmitter can be helped by placing it on something that will act as a ground plane like a metal filing cabinet or a refrigerator. The most common examples are found on automobiles and are used for broadcast radio, cb. The earth ground below the antenna, a conducting surface a least. Therefore, if a radio station is broadcasting at a.16 565 46 152 441 1136 653 898 798 114 1235 582 1050 391 202 1093 1172 872 405 697 1032 131 761 14 1431 1417 708 621 600 162 1194 784 330 803