Although your link is to Wimo in Germany, this is actually an antenna from the company “Alpha Antennas” in the US. ( http://AlphaAntenna.com )
There are a few companies that have similar antennas, including a €99 (now €156) one from Spain that I am testing at the moment. ( https://vk2ji.com/equipment/antennas/komunica-bazooka-780-wideband-mobile-vertical/ ). They are all compromise antennas. They are NOT flat across the bands. The one you have found apparently as well as the vertical element, has a horizontal element as well AND a counterpoise wire. As it’s specs say, it’s both vertical and horizontally polarised!! It’s supposed to work as an NVIS and a DX antenna…
Here’s the trace of the antenna you are looking at from the manual (link on the same page you indicated).
Here’s the operational description:
The Alpha Multiband Antenna is designed to simultaneously provide high-angle radiation
(near vertical incidence – NVIS) and low-angle radiation (long-range and DX) propagation.
The targeted deployment variable includes the ability to launch your signal in the opposite
direction the NVIS element is run away from the base of the antenna. Based upon how the
tripod is tilted & NVIS element is deployed, this can provide directional propagation between
0 to 90 degrees above the horizon. While the NVIS element enhances short-range sky wave propagation, which varies from 0 to 300 miles, the Vertical element in tandem with the
NVIS element enables long-range & DX propagation for distances greater than 300 miles.
The Alpha Multiband Antenna may be used with tactical HF (high frequency) radios on the
frequency range of 3.5 to 29.7 MHz (54.0 MHz when mounted on the tripod options) with a
maximum RF power of 500 watts PEP SSB, 250 watts CW, or 100 watts digital.
For me, at €349 without the tripod or €389 with the tripod, it’s too expensive without knowing if it works as well as described.
I suggest you look to see if there’s an INDEPENDANT review in any US amateur magazine or on eHam before spending that level of money.
EHam.net review is at: http://www.eham.net/reviews/detail/10357
Hmm, this is interesting … The last set-up action is listed as:
Step 8 – Attach your coax from your tuner to the SO-239 on MTCH-2.1 (that’s the tripod).
This is supposed to be an antenna that doesn’t require a tuner …
Tuner Free & Directional
Alpha Multiband Antenna