Ads
related to: wire yagi 40 meters 1 mile length
Search results
Results From The WOW.Com Content Network
A single ground wire can provide antenna gain in the 3–6 dB range. This is a reflector element used to form a 2-element Yagi beam antenna. The wire length for the reflector element is 5% longer than the dipole-driven element positioned above it. The dipole is located at a distance of 0.15 wavelengths above the reflector element.
Yagis have been built with 40 directors [3] and more. [11] The bandwidth of an antenna is, by one definition, the width of the band of frequencies having a gain within 3 dB (one-half the power) of its maximum gain. The Yagi–Uda array in its basic form has a narrow bandwidth, 2–3 percent of the centre frequency. [4]
"A two-element, three-band quad, with elements mounted only 35 feet above ground, will give good performance in situations where a triband Yagi will not." [12] Shorter boom Orr (1996) [13] shows a 10, 15, and 20 meter, 2 element quad with boom length of 6′10″. Internally stackable
On October 10, the Third National Radio Conference made three shortwave bands available to U.S. amateurs [8] at 80 meters (3.75 MHz), 40 meters (7 MHz) and 20 meters (14 MHz). These were allocated worldwide, while the 10-meter band (28 MHz) was created by the Washington International Radiotelegraph Conference [ 9 ] on 25 November 1927.
A Yagi antenna may have a reflector on one side of the driven element, and one or more directors on the other side. If all the elements are in a plane, usually only one reflector is used, because additional ones give little improvement in gain, but sometimes additional reflectors are mounted above and below the plane of the antenna on a ...
Very high frequency (VHF) is the ITU designation [1] [2] [3] for the range of radio frequency electromagnetic waves (radio waves) from 30 to 300 megahertz (MHz), with corresponding wavelengths of ten meters to one meter.
Often random wire antennas are also (inaccurately) referred to as long-wire antennas.There is no accepted minimum size, but actual long-wire antennas must be greater than at least a quarter-wavelength ( 1 / 4 λ) or perhaps greater than a half ( 1 / 2 λ) at the frequency the long wire antenna is used for, and even a half-wave may only be considered "long-ish" rather than "truly ...
[citation needed] The loading provided by the helix allows the antenna to be physically shorter than its electrical length of a quarter-wavelength. This means that for example a 1 / 4 wave antenna at 27 MHz is 2.7 m (110 inches; 8.9 feet) long and is physically quite unsuitable for mobile applications. The reduced size of a helical ...