Overview

WiMo X-Quad Antennas

WiMo X-Quad Antennas, with separate monoband models for 144-146 MHz or 430-440 MHz, represent a refinement of VHF and UHF cross-polarized Yagis. They are well-known in Europe as "multi-element quads"—an antenna with aluminum elements, not a wire and fiberglass antenna—which offer excellent gain with a relatively short boom length. X-Quads are a great solution due to their short length and lightweight construction, especially for VHF/UHF satellite systems which require rotation in all compass directions and elevations. Two X-Quad Antennas, one for 144-146 MHz and one for 430-440 MHz, may be mounted at opposite ends of an azimuth-elevation rotator cross-boom for high-performance full duplex Satellite operations. For either or both bands, X-Quad Antennas may instead be used in a stationary mount, as pictured, for all-mode terrestrial operations. In either application, multiple X-Quad Antennas may be stacked vertically and horizontally for additional gain and tighter patterns.

The WiMo X-Quad special features, developed specifically for Satellite Amateur Radio include:

* Switchable Polarization Plane; horizontal/vertical/right hand circular/left hand circular (remote switching requires optional equipment)
* High gain compared to other antenna forms due to the "stacking effect"
* Short boom length and compact design
* Back-end boom or mid-boom centered mounting to the mast is possible

The radiator element is a "stacked quad" multi-element beam, for which linear polarization can be compared to a crossed slotted radiator. However, the advantage of the X-Quad is that it can be optimally used for the desired polarization by simply changing the feed. Compared to a typical cross-polarized Yagi, all directors and reflectors are active in the X-Quad, which enables the compact design.

As with cross-polarized Yagis, switching is accomplished on the mono-band X-Quad either by a coaxial relay or with a band specific WiMo Remote Polarization Switch (sold separately). If the remote switch is mounted at the antenna, then only one coax cable and a 4-conductor control cable are required, sold separately. If the Switch is used at the station, then two coaxial cables from the antenna to the station are needed.

The WiMo X-Quad Antenna can also be permanently set for circular operation by using an optional, band-specific Phase Line. The secondary elements are arranged diagonally in relation to the square-shaped driven element, which corresponds to the voltage distribution on the radiating element, for the most favorable results. In comparison to Yagi antennas, the X-Quad pattern and tuning are affected less by the influence of external fields, making them ideal for installation under a roof, in an attic space.

All elements are electrically conductively connected with boom and cable outer sheath, thus eliminating interference from atmospheric noise. Two Type-N female coaxial connectors, one for each polarization, are mounted in a housing that is waterproof. Boom and elements are made of aluminum, all hardware is stainless steel. Construction and design of the antennas are protected by law (DBGM). The antennas are designed for boom-end mounting; however, alternatively the mast clamp can be mounted in the middle of a non-metallic boom. These antennas have a split boom, so their transport length is only 29.53 in. (75cm) for the 2m antenna and 25.59 in. (65cm) for the 70cm X-Quad. For portable operations they can be stowed away comfortably in the trunk of car and their shipping costs are comparatively low.

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