MAKE A MEME
View Large Image
| View Original: | Ground dipole ELF antenna.svg (1530x1231) | |||
| Download: | Original | Medium | Small | Thumb |
| Courtesy of: | commons.wikimedia.org | More Like This | ||
| Keywords: Ground dipole ELF antenna.svg ground dipole antenna used to transmit extremely low frequency ELF radio waves showing how it works This is modeled on the U S Navy ELF radio transmitter at Clam Lake Wisconsin which was used to communicate with submerged submarines at a frequency of 76 Hz from 1989 to 2004 The antenna consists of two electrodes buried in the Earth G 14 miles 23 5 km apart linked by overhead transmission lines resembling ordinary power distribution lines to a power plant transmitter P The system functions as a giant vertical loop antenna in which the earth serves as part of the loop The power plant drives the antenna with 300 amperes alternating current at 76 Hz which flows through one transmission line in looping currents I deep in bedrock from one ground electrode to the other and back through the other transmission line the drawing shows only one direction of the alternating current The AC current creates an alternating magnetic field H which radiates ELF waves yellow The radiation pattern is directional with two lobes maxima off the ends of the wire This drawing was made with information from cite journal Jones David Llanwyn Sending signals to submarines New Scientist 26 1463 37-41 Holborn Publishing Group London 1985-07-04 http //books google com/books id NOPpwVvNu44C pg PA39 dq ELF+transmitter hl en sa X ei dhI4T8KrIbLZiQKCg8yqCg ved 0CFYQ6AEwBA v onepage q sanguine f false February 17 2012 among other sources 2012-02-29 own Chetvorno cc-zero Uploaded with UploadWizard Antenna diagrams Alternating current | ||||
