Aurora from space

Aurora can affect propagation conditions over the polar routes and is often used to enhance VHF propagation, especially at 50 MHz and sometimes the 144 MHz Amateur bands. At times of auroral displays, HF radio signals traveling over the polar route will develop a distinctive warbling sound. You can often hear these effects on 14 MHz SSB signals that have followed the great circle route over the polar region. Read the rest of this entry »