WiMo Yagis 2350 MHz (13 cm, SHF)

Technical description

The 23 and 13 cm bands belong to the UHF bands with the highest frequencies and offer very unique and fascinating propagation conditions. Here, antennas with high gain are essential to achieve good results in contests or DX. Due to the relatively short wavelength, the demands on precision in antenna construction are significantly higher than, for example, on 2m. Here, an error of a few millimetres has a very significant effect and can lead to poor matching or non-optimal gain.

The WiMo SHF Yagis for 23 and 13 cm are based on the proven design of DL6WU. The square boom tubes are drilled in one piece on an automatic production machine to keep the tolerances as low as possible. In the same way, the aluminium elements are automatically sawn with a maximum length tolerance of 0.1mm. These elements are then inserted and fixed into the boom with precise centring. The dipole uses a balun made of semi-rigid coaxial cable, making it very robust and accurate to manufacture. In addition, the connections of the balun are covered with protective lacquer and the connection box is sprayed waterproof. Of course, the dipoles for the WiMo Yagis have an N-connector. For 'hanging' systems, the baluns are also offered with 180° phase reversal, which simplifies the laying of coaxial cables for stacked antenna systems considerably. The dipoles are also offered individually as spare parts.

To keep the noise caused by side lobes low, a reflector with 8 elements is used. This ensures a good gain/temperature ratio, which is particularly important for EME and satellite operation. Here, the antennas are also adjusted in elevation so that the end points to the ground. And a lot of 'man-made noise' comes from the ground. The WiMo SHF antennas are delivered pre-assembled, only the boom parts have to be mounted. The shortest designs of the Yagis are designed for foremast mounting, the longer models have a downstand and have to be installed on the end of the rotating tube or a boom.

Application description

The SHF-1340 Yagi (40 elements)

The SHF-1340 is the smaller of the 13cm Yagis produced by WiMo. Nevertheless it offers a high gain of 18.7 dBi. With only 160cm length it still fits into every antenna system (foremast mounting) and thus offers a good entry into the world of 13cm. If you drill cross holes in the boom, you can mount this antenna vertically, e.g. for relay operation. The dipole with N-connector is rated up to 500W.

The SHF-1367 Yagi (67 elements)

The SHF-1367 Yagi with 3m length and 22.1 dBi gain is perfectly suited to be operated individually or as a group. The bandwidth of the antenna covers the whole 13cm band without loss, even in rain it does not detune. The dipole (N-socket) can handle up to 500W and is also available in a version with 180° phase shift, this simplifies the construction and cable routing for group antennas. The boom is supported by a lower strut.