EuroSpeleo 2016
How Earth-Current Antennas Really Work
Oral|Dr David Gibson

Abstract
With cave radio equipment, there has been a trend away from the use of induction loop antennas to the use of so-called earth-current antennas, i.e. long wires grounded at both ends. Both the HeyPhone and Nicola system use this type of antenna. However, the popular explanation for how this antenna works is fallacious. The antenna does not operate by allowing the current to flow in a 'big loop' in the ground, nor is it a 'conduction mode' of operation. In fact, it does not depend, fundamentally, on current flow in the ground at all. The fact that the popular explanation is wrong is important because, if we do not understand how the antenna works, it is difficult to know the best way to use it, nor how to design a better one. In this short talk, without too much emphasis on theoretical physics, David Gibson outlines a more useful model - that of the Grounded Horizontal Electric Dipole.
More from 2016
Poster|Mr Nigel Steel
Poster: Cave archaeology and Photogrammetry
Poster|Dr David Gibson
Poster: The Cave Radio & Electronics Group Journal
Workshop|Mr Robin Gray
Art Workshop 3 - Drawing cavers in costume
Film|Mr A & A Freem
Caver's Cinema - Thursday
Poster|Mr David St. Pierre
Poster: Grotte Casteret (Gruta Helada de Casteret) An annotated and illustrated bibliography. 2007
Oral|Prof Weihai Chen
Karst Landscape and Caves in China
Oral|Mr Bernard Chirol
Cyprus caving history
Film|Mr A Freem
Caver's Cinema - Monday
Oral|Mr Mike Futrell
Workflows and Data Formats Supporting Wider Use of Cave Data
Oral|Mr Michael Laumanns
Middle East A reminiscence of 4 expeditions to Iran and Iraq between 2000 and 2007 (M. Laumanns, Speleoclub Berlin)