Model 615

A properly chosen antenna can greatly enhance the quality of short-range shortwave broadcasting. Ideally, the antenna should handle high power to ensure high signal-to-noise ratio at the receiver, have a wide frequency bandwidth for selection of the appropriate frequency, allow diplexing of two transmitters on one antenna, and produce radiation at high elevation angles.

The Model 615 exhibits all the features of this ideal short-range broadcast antenna. Power-handling capability is 100 kW or 250 kW AM carrier power.

The frequency bandwidth is either 2.3-18 MHz or 3.2-18 MHz, and the radiation pattern is essentially omnidirectional with the majority of the energy directed overhead. Broadcast coverage is in the approximate range 0 to 1,500 kilometers from the transmitter station.

The 615 is truly a wideband antenna, and not merely tuned to the specific broadcast bands. It achieves high efficiency and low VSWR at any frequency within its operating range.

The 615 employs the same high-quality, exhaustively tested components and materials as all TCI antennas. Feedlines and catenaries are composed of a high-strength steel core and a highly conductive, corrosion-resistant, welded coating of aluminum. All feedline and radiator tip insulators are made of high-strength glazed alumina, a material with an extremely low loss tangent (.001), which is virtually impervious to the effects of ultraviolet radiation, dirt and salt spray.

Fiberglass material is not used anywhere in the antenna. Complete fabrication and preassembly are accomplished in the factory. Installation consists of only the tower erection and hoisting the preassembled curtains. The few connections required are accomplished with nuts and bolts.