Which of the following results from the fact that signals propagated by the ionosphere are elliptically polarized?
Digital modes are unusable
Either vertically or horizontally polarized antennas may be used for transmission or reception✓Правильный ответ
FM voice is unusable
Both the transmitting and receiving antennas must be of the same polarization
Объяснение
Passage through the ionised, magnetised ionosphere rotates and reshapes the wave so it arrives elliptically polarized, which means it has components in both the vertical and horizontal planes. Either orientation of antenna can therefore recover the signal, and the two ends do not have to match.