The inductor core in the ICE suppressor saturates due to the low
frequency components of a surge and becomes a short circuit, thus
relieving the gas tube of much of the current. That can happen before
the gas tube begins to conduct, as gas tubes exhibit a delay. In
addition, the suppressor appears as a mismatched load when a surge is
applied (combined operation of the inductor and gas tube) and much of
the surge energy is reflected back to the antenna. Of course, the
antenna is also a mismatched load to much of the surge energy, so some
of that energy is reflected back to the surge reflector, and goes back
and forth. In the process, energy is dissipated in the feedline.
Spreading of the energy among several components of the system helps
these small suppressors to survive fairly large surges.
The gas tubes used are typically rated for up to 20,000 Amperes. Their
life is limited at that current level, though. The voltage across them
while they are conducting is typically 15 to 20 Volts. Gas tubes
operate just like spark gaps. The advantage over a simple spark gap
(spark plug, for example) is that the characteristics are regulated by
the composition of the gas and the electrodes and by the gas pressure in
the tube. Thus they can achieve high operating voltage when not
conducting, low operating voltage while conducting, and stable
characteristics that is independent of atmospheric conditions of
pressure and temperature. The working parts are protected from
contaminants and oxidation, which affect simple spark gaps.
A major component of the PolyPhaser and ICE suppressors is the blocking
capacitor, which limits the energy that is passed to the rig while
energy is being dissipated in the suppressor, feedline, and antenna.
These devices work quite well. Similar technology and components,
including gas tubes, have been widely used for years to protect
electronic components from surges. Read _Protection of Electronic
Circuits from Overvoltages_, by Ronald B. Standler, 1989; John Wiley &
Sons, Inc., particularly Part 2, Chapters 7 through 15, for information
about gas tubes, varistors, avalanche and Zener Diodes, semiconducor
diodes and rectifiers, thyristors, impedances and current limiters,
filters, isolation devices, and parasitic inductance and how these
devices may be used to protect electronic equipment from overvoltage
stresses such as those associated with lightning. This book may not be
available in many public libraries but is available on inter-library
loan from college and university libraries.
73 de WOØW
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