[Lowfer] EH Antennas

[Lyle Koehler]

>>"The external part of the coax shield is "invested" by this strong >field.
>>Such may cause a part of RF to reach the RTX and generate an >increase of
>>the SWR or RF burns."

>Could actually be the result of what they define as a high intensity field
>due to the small size of the antenna relative to a WL.

Yes, that's my point. There are high intensity fields in the immediate
vicinity of an electrically small antenna, and these fields will induce RF
currents in any nearby conductor, whether it is physically connected to the
"radiator" or not. I believe that is why the CFA, the Isotron, and other
"magic" antennas sometimes appear to work fairly well despite their small
size. What really activated my BS alarm was the author's statement that
there is RF on the coax shield, but that the coax doesn't radiate. That is
indeed a remarkable breakthrough in physics!

One way to perform a reasonably convincing test of the E-H antenna principle
would be to build a model that is scaled for the HiFER band, eliminate the
transmission line completely, and feed it with a 1.8 milliwatt
battery-powered transmitter (such as the one in the solderless projects on
my web page at www.computerpro.com/~lyle). The whole transmitter/antenna
system, including the battery, keyer and any associated wiring must be
contained within a volume that is not appreciably larger than the "antenna"
itself. Otherwise there is no way to know what part of the assembly is
radiating. Then you mount the whole assembly on a fiberglass or PVC pipe, at
least 25 feet away from any conducting masts or wires. If the field strength
at a hundred meters from the E-H antenna is better than you can get from the
same transmitter feeding a plain old top-hatted, ground-mounted vertical of
comparable size, it _might_ be worth building a LowFER version. Or you might
want to re-check your measurements...

Lyle, K0LR