Magnetic directional antenna

摘要

The figures given show the main element (10) and an additional element (11) that is directly fed through a phase line (12). The main or principal element is composed of a copper ring, open at one position where the variable capacitor is fitted. The antenna is tuned over only a set frequency range, so that it is not necessary to form the entire capacitance needed for resonance in the rotating part. A fixed capacitor in parallel with the rotating part is also provided.