InnovAntennas OP-DES Shortwave Yagi (Monoband)
- Flat SWR over wide range
- Adjustable frequency for minimum SWR
- High power - up to 5 kW
- Excellent gain
- OP-DES Yagi
- Mast clamp
The "OP-DES" (Opposing Phase Driven Element System) Yagi antennas are a relatively new development by InnovAntennas. The dipole radiator of these antennas is angled backwards parallel to the boom. This results in opposing phase relationships in the two side parts, which ensure a very clean directional pattern with few side lobes. The result is a very good gain over a wide frequency range, with a good front-to-back ratio.
The adjustable radiator allows the position of the SWR minimum to be shifted, so the 10m antennas can also be used on 11m. The dipole of an OP-DES antenna has a low impedance of 50 Ohm. This eliminates the need for matching elements; all transformations take place in the dipole itself. For this reason, the antenna is offered without a balun, but a cladding wave blocker can be used without any problems.
The coaxial cable is connected directly to the dipole, allowing power levels of 5 kW and more. Like all InnovAntennas Yagis, the OP-DES antennas are extremely robustly constructed, the larger models use guy wires for the boom. All elements of the antenna use high quality aluminium, the clamps and screws are made of stainless steel. The supplied mast clamp is designed for masts up to 50mm diameter.
Monoband Yagis are often used at contest stations, or when you want to use only one band for a certain time, for example to concentrate on a specific target during sunspot minimum. Another advantage of monoband antennas is the possibility of stacking, i.e. the arrangement of several antennas of the same type on top of each other. Here, the InnovAntennas Yagis provide all the necessary technical specifications, taking the guesswork out of stub spacing.
The InnovAntennas OP-DES Yagis are designed through careful numerical optimisation to provide excellent gain with good bandwidth. The entire band is always covered, and on some 10m models the dipole can be adjusted to use both the lower 10m and 11m bands. The manifold experiences of the developer Justin, G0KSC ensure a smooth use of the antennas in practice, often supported by a lively exchange with the users.
A special feature of the 3 Element OP-DES Yagi for 20m is the possibility to choose whether to optimise for maximum gain or best forward/back ratio.
|InnovAntennas OP-DES Shortwave Yagi (Monoband)
|Max. Power [W]
|No, not required