Ads
related to: umbrella antenna diagram for car audio
Search results
Results From The WOW.Com Content Network
English: Diagram of an umbrella antenna, a toploaded wire transmitting antenna used in the medium frequency (MF), low frequency (LF) and very low frequency (VLF) bands. It consists of a steel mast (grey) insulated from the ground, with diagonal wires radiating from the top, anchored to the ground in a circle around it.
The trideco antenna is a huge specialized umbrella antenna used in a few high power military transmitters at very low frequency (VLF). [ 5 ] [ 6 ] In a conventional umbrella antenna, the use of the sloping guy wires as the capacitive top load has some disadvantages: First, since the umbrella wires must be anchored to the ground, their length is ...
An umbrella antenna consists of a central radiating tower with multiple wires attached at the top as a "capacitance hat", that extend out radially from the mast and are insulated at their ends; the overhead configuration resembles an open metal umbrella frame, hence the name "umbrella antenna".
Thus the umbrella antenna uses the guy wires as the top-load part of the antenna. In all these antennas the smaller radiation resistance of the short radiator is increased by the capacitance added by the wires attached to the top of the antenna. In some rare cases dipole antennas are used, which are slung between two masts or towers.
Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts.
The name comes from its resemblance to an inverted letter "L" (Γ). The T-antenna is an omnidirectional antenna, radiating equal radio power in all azimuthal directions, while the inverted-L is a weakly directional antenna, with maximum radio power radiated in the direction of the top load wire, off the end with the feeder attached.