50MHz 5-Element OP-DES Wide Band Yagi .

InnovAntennas OP-DES 50 MHz Yagi Antennas are a relatively new development from InnovAntennas. OP-DES stands for Opposing Phase Driven Element System, in which the ends of the dipole radiator of these antennas is angled backwards towards the reflector, parallel to the boom. This results in opposing phase relationships in the ends of the driven element, providing a very clean directional pattern with few side lobes. The OP-DES Yagi has optimized gain over a wide frequency range, while retaining a good front-to-back ratio.

The driven element dipole of an OP-DES antenna has a low impedance of 50 ohms. This eliminates the need for matching elements or a transformer balun. For this reason, the antenna is offered without a balun, but an RF choke balun made of ferrites on coax should be used at the feedpoint terminal studs. With the coaxial cable directly connected to the driven element dipole, well over full legal limit power levels are possible. Like all InnovAntennas Yagis, the OP-DES 50MHz antennas are extremely robustly constructed; the larger model uses truss cables for the boom. All elements of the antenna use high quality aluminum, the clamps and screws are made of stainless steel. The supplied mast clamp is designed for masts up to 2 in. (50mm) diameter.

Application Description
Monoband Yagis are often used at contest stations, or when you want to use only one band for a certain time, for example to focus on a specific target during sunspot minimum. Another advantage of monoband antennas are the stacking possibilities, i.e. the arrangement of two or more identical antennas properly spaced from each other. InnovAntennas Yagis provide all the necessary technical specifications, so there is no guesswork about the stack spacing.

The InnovAntennas OP-DES 50 MHz Yagis are designed through careful numerical optimizations to provide excellent gain with good bandwidth. As a result, a low SWR of 1.1:1 is achieved in the frequency range of 50.0 - 50.6 MHz (6-element) or 50.0 - 51.35 MHz (5-element). The experience of the developer Justin, G0KSC ensure superior operations with these antennas in practice, often supported by a lively exchange between users.