Zenneck Waves

[Guest guest]

Hi everyone,

Been reading about Zenneck waves recently, and believe these play a

significant part in the operation of transmitted field instruments.

A good web site on these can be found at:

htttp://www.tfcbooks.com/articles/tws4.htm

A Zenneck wave, is a wave whose field amplitude varies inversely as the

square root (!) of the horizontal distance from the source. It IS NOT a

Hertzian wave!

A hertzian wave will vary as the square of the distance from the source. The

difference in powerof a hertzian wave between a point 2' from the tube and

4' from the tube would be 1/4th or .25 . As a Zenneck wave, the difference

in power between 2' and 4' from the tube would be the 1/1.414 or . 707 --

that is nearly three times as strong as a hertzian wave.

Zenneck waves are created best at lower frequencies and from cylindrical or

round antennas. A portion of the RF transmitter that is not converted to

Zenneck waves by the antenna is converted to hertzian waves. Most

conventional RF antennas are made to form hertzian waves. In 1937, a test

using antenna designed to form Zenneck waves was done. At 150 MHz, the

transmitter produced a field strength 100 times lower than predicted from

hertzian physics! This is analagous to what has been noticed with an R/B

device. The radiated RF field is very miniscule compared to the theoretical

expected field.

Zenneck waves travel between boundary layers - such as the earth and the

atmosphere. They are considered by some to have a longitudinal component -

similar to the concept of a single wire conductor as used by Tesla. It is

possible that they will propagate in tissues in a similar manner.

One other aspect to Zenneck waves is that they are best created from a

damped RF transmission.

Far too many analogies here to the observed effects from transmitted field

devices to be ignored.

Jim Bare