Umbrella antenna
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An umbrella antenna is a capacitive electrical lengthen antenna, which consists in most cases of a groundfed mast radiator, at whose tops wires are fixed, which run to the ground. These wires have to be divided at least by one insulator. Because such a construction looks like an umbrella without clothing, it got therefore its name. the task of the wires can be also done by the anchor guys of the mast, but in many cases ( especially for antennas, which are very short in comparison to radiated wavelength) additional wires are required. It is also possible to build umbrella antennas with a grounded tower. At such umbrella antennas a separate feeder to the umbrella wires, which are as well insulated against the mast and the ground are required. Umbrella antennas are and were used as single mast antennas for LF- and VLF-transmission. They were used at most OMEGA-transmitters and are used at LORAN-C stations with approximately 200 metre tall masts.
