The fifth presentation at the V/U/SHF 2023 meeting will be given by Peder, SM5DWF. He will present his improved Boxkite antenna for 6m and 2m.
The Boxkite approach, referring to extensive work of KF2YN, Brian Cake, for VHF/UHF antenna construction will be discussed, starting with simulation of interesting features for DX work, followed by description of an improved experimental version of my short-boom (84 cm) Boxkite for 50 and 144 MHz. The Ratiometer Measurement Method for checking the power intensity pattern for chosen polarization of at first hand the electrical field, will be presented with my latest available results.
My antenna will be based on the commonly available 4NEC2 software, giving possibilities to study influence of soil on the wave propagation of both electric and the magnetic polarization components. Hence, surface wave predictions yield near plane wave distributions for ratiometer study of radiation pattern of the antenna under test, comparing its properties with a reference antenna.
My results, so far obtained, tell that use of multiple frequencies are possible with low SWR over at least 2 MHz of the 2 and 6 meters amateur bands, need just one single coax feed. Work is in progress for further study, example the combination of 70 cm and 2m, as well as 23 and 70 cm, again with single feed. Short boom Boxkites seem to be attractive, also for low wind load array construction, and with reasonable impedance properties as function of used frequencies.
I welcome feed-back from experts in the field for a further exploration of similar types of compact antennas, even at much higher frequencies, up to several GHz and further into the THz and near optical region.