The leading cause of modern solid state receiver failure is voltage buildups on long antennas and feedlines caused by dry wind, dust, and snow storms, and by nearby and far-field lightning strokes. A nearby lightning stroke can, by induction, place many thousands of volts on an antenna system. Test have shown that damaging voltages can be induced by a lightning stroke as far as 15 miles from the antenna site. These phenomena are called transients. Some solid state components can be destroyed just by the static electricity from the touch of an ungrounded finger, and some thousands of volts entering your receiver through the antenna input is guaranteed to damage it. Because of this, we have developed our line of Zap Trapper™ Gas Tube electronic receive-only lightning arrestors. The gas tubes consist of two metal conductors, separated by a space filled with a rare gas under pressure. When the design voltage is reached, the gas, normally a non-conductor, ionizes and becomes a conductor, thus shunting the damaging voltage surge to earth ground, before it can enter the receiver. The transition time, from non-conducting to conducting, is very, very fast, on the order of just several nanoseconds, which is much faster than the voltage wavefront rise time of lightning.

The transmit-type gas tube lightning arrestors that have been available for several years provide some protection, but because they must pass the transmitted RF voltage without conducting it to ground, they cannot conduct at as low a voltage as a pure receive-only type. In fact, our receive-only Zap Trappers™ fire at only 1/7th the voltage of the commonly available 200 Watt transmit-type lightning arrestors, thus providing 7 times the receiver protection, and that, we think, is the most important development in the SWL antenna field in years.

The biggest enemy of outdoor antennas is corrosion at the connections between the wires and the coils or traps used in the antenna in the presence of moisture. Received signals are only some few microvolts in strength, and don't pass through a film of corrosion very well. We have addressed this problem by not only soldering all our RF connections, but by enclosing all our connections to coils and traps in ultrasonically-welded hermetically-sealed ultraviolet light-protected trap covers. We have been doing this for many years, and there are many Eavesdroppers™ in the field still providing excellent reception after more than ten years of exposure.

With the development of our receive-only lightning arrestors and our ultrasonically-welded trap covers, we have virtually eliminated both the major problems plaguing passive antennas. No other manufacturer, foreign or domestic, incorporates these most desireable features in their SWL antennas. In fact, only one other manufacturer even bothers to solder the connections, and that is not the one who is always advertising slopers either. Most manufacturers, including the sloper people, only clamp the antenna wire between two nuts on the coil. This works for a while, but in time, interface corrosion occurs. Remember that dissimilar metals in the presence of moisture produces galvanic action. In an antenna, the wire is copper, the hardware is plated steel or brass or even stainless steel, and the juncture of the two materials forms a little battery producing corrosion. Soldering prevents moisture from entering the connection, and that's why we do it.

Which of our antennas should you choose? If your interests lie primarily with the International Shortwave Broadcasting bands, with only a casual interest in Utility stations and the AM Entertainment Broadcasting band, then either the Model T or the Model C would be the best choice, with their multiple resonances on the principal Shortwave bands. The Model T is fine for many installations and locations, and comes with 100 feet of twinlead feedline already attached. The Model C is for use where there is considerable locally-generated noise, or where the feedline must be run alongside electrical wiring, close to heating ductwork, or run over raingutters. Electrical line noise, computer-generated noise, and the detuning from the feedline proximity to large metal objects can be largely overcome with the use of shielded coax. If you do a lot of listening to the Utility stations and the AM Broadcast band, then the "SLOPER" would be your choice. The "SLOPER" doesn't have quite the signal quality on some of the Shortwave bands that the Models T & C do, but it does do better on the AM band, and the Tropical bands, 90 and 120 meters. Please note that we build our "SLOPER" with the same care and engineering we use on our original Eavesdroppers. We do not build a short version of the "SLOPER" because our tests indicate that the short "SLOPER" doesn't perform as well as our Eavesdroppers™ do on the bands it covers. Available room is also a consideration. The T's & C's, at 42 feet overall length, can be installed in your attic and bent around to fit if necessary, but the "SLOPER" cannot be mounted in a "sloper" configuration in an attic, and at 67 feet, probably wouldn't fit in your attic at all.