ABSTRACT
Voice of America Coverage Analysis Program is available online and only requires the user to input the required information to get propagation predictions. In addition there are several other online alternative propagation engines that can be used for propagation predictions, some specifically aimed at Amateur Radio Operators but generally useful for High Frequency (HF) broadcasters who want a second opinion. Amateur Radio operators—the first developers of HF communications—use single sideband almost exclusively. HF broadcasting uses the 2–26 MHz range of frequencies—from just above the Medium Wave (MW) Amplitude Modulation (AM) broadcast band to near very high frequency; three octaves of frequencies coverage. HF broadcasting is different from conventional AM on the MW broadcast bands. HF antennas are generally horizontally polarized and are balanced. HF broadcasting for medium distances, 1000–2000 miles, typically use broadband log-periodic type antennas. International HF broadcasting over long distances typically uses large curtain arrays, high transmitter powers and flexibility in operating frequency.
