Luther Gulseth wrote: > Most any frequency on HF is world wide capable (depending on the mode > you use), and most avionics are AM, which has an unlimited range.
Range on HF bands is highly variable, though. During the day you only get ground wave, which is mostly line of sight, on the lower frequencies. Up around 20 or 30 MHz (CB and the amateur 10 meter band) you can *sometimes* get skip during the day, but only if the sunspot count is high and the ozone layer is cooperating. I used to have a 10 meter band HF transceiver. There were days I could talk to Argentina with 80 watts, and there were days when I could barely get out of my own backyard with the same power level. If BPL (broadband over powerline) Internet access catches on, I expect all the HF bands will get trashed by the interference.
