Umbrella antenna 1910

Autor/Urheber:

John Ambrose Fleming

Shortlink:

https://dewiki.de/b/2405cf

Quelle:

Wikimedia Commons

Größe:

771 x 593 Pixel (49030 Bytes)

Beschreibung:

An umbrella antenna, a monopole antenna used for LF transmitting, at the longwave wireless telegraphy station of the Amalgamated Radiotelegraphic Co. at Cullarcoats, on the Northumberland coast near Newcastle, England in 1910. It consists of a 220 ft wooden lattice tower with two wires running from the transmitter in the building to the top, connected at the top to 24 bronze wires extending radially from the mast on a diagonal, attached to ropes which are anchored to the ground on a circle 220 ft in radius. The vertical wires served as an electrically short quarter-wave monopole antenna while the radial wires served as a capacitive "top hat" to increase the current in the vertical radiators. The other side of the transmitter was connected to a ground (Earth) system consisting of buried cables radiating from the base of the mast. It transmitted with both a spark gap transmitter and a Poulsen arc transmitter on a frequency of 200 kHz.

Kommentar zur Lizenz:

Fleming died in 1945.

Lizenz:

Public domain

Credit:

Retrieved February 17, 2015 from John Ambrose Fleming (1910) The Principles of Electric Wave Telegraphy and Telephony, 2nd Ed., Longmans, Green and Co., New York, p. 797, fig. 16 on Google Books

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