ALLISS

ALLISS is a fully rotatable antenna system for high power shortwave radio broadcasting in the 6 MHz to 26 MHz range. An ALLISS module is a self-contained shortwave relay station that is used for international broadcasting.

ALLISS is a special design case of HRS type antennas. True ALLISS systems have solid radiators (horizontal radiating elements) versus tensioned flexible (open) radiators found with all other variations of ITU HRS type antennas systems. The name is based on a concatenation of two French towns ALLouis and ISSoudun.

There are some factors that separate true ALLISS technology from 'run-of-the-mill' rotatable HRS Type antennas Thales pseudo-ALLISS rotatable antenna designs were procured from other antenna manufacturers that Thales acquired by corporate transactions. Technically only solid radiators distinguish true ALLISS systems from all other rotatable HRS type antennas. Only about 12% (estimate) of all HRS antennas in use globally are rotatable, and of these only 28 of the ALLISS systems have solid radiators. One must assume that only about 10% of HRS type antennas are rotatable, but compiled statistics are fragmentary. Only about 20% of rotatable HRS antennas are ALLISS, but this may be a slight overestimate. The Transmitter Documentation Project has most but not all stats on shortwave relay station antennas in use or historical. The Chinese SARFT is said to contain replicated ALLISS module technology, so to consider ALLISS technology as being exclusively in the domain of Thales is no longer true.

Information about ALLISS can also be found associated with Thomson-CSF—the previous name of Thales Group.

ALLISS technology, due to its cost and complexity—is out of reach to most consumers as a consumer product. Cheaper solutions to ALLISS exist in the shortwave broadcasting technology area. As a rule of thumb ALLISS systems should only be purchased if 360 degrees of coverage is necessary. ALLISS is only used by well funded broadcasting and telecommunications operations that intend to use the modules over their design lifespan of 50–60 years.

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