With the "lower" channels, as folks say, here's where you will increasingly get into trouble. I just got back from a meeting of communications officials. How many of you have heard of Automatic Link Establishment (ALE)? NO, NO, not something you can drink!
It is where the radio "polls" thousands of frequencies in fractions of seconds and establishes 'links" according to the Maximum Usable Frequency (MUF) and what is the best frequency to use. All the radios in the agency, both transmitters and receivers, are sampling frequencies at the same time. They
call each other and the user has no idea which HF frequency he is on; he just picks up the mike and talks and the receiving station gets the call and the traffic is passed. If the agency has.....say 30 frequencies ranging from 2 MHZ to 26.800, the radios are constantly polling each other and establishing links with each other at unfathomable rates! Now, let's say the best "link" happens to be on 26 MHZ, BUT there are unauthorized people filching there! Rest assured, it WILL get noticed and the military authorities will go after those who operate there thinking there is a "freeband" for them to use at will. If you know what Pactor or RTTY sounds like, if you are on one of those unauthorized frequencies and get a "RTTY" burst lasting about 7-8 seconds, this is a radio polling others in the network. You, OTH, won't even know that the network has "noticed" you. Radio also keeps a log of the results of its polling, and that's how the military folks know you were there---if they don't outright hear you. But you WILL interfere with them, and THAT ain't a good idea--even if you never hear a word!! It doesn't mean that frequency isn't being used; it's just in a different way from the way we think of using a CB radio!
So, in today's changing technology environment, don't automatically assume that "that channel ain't being used!"
The uses to which military and commercial entities put their commo resources are not dependent on what we as civilians think. They have objectives, communications plans, and needs that *we* don't understand. And as these needs change, these agencies, particularly military, are relying more and more on what we think is "obsolete" when, in fact, "old" technology is being used, just in new and better ways. ALE has been around since WWII, but in today's security environment, it has found new advocates. You wouldn't GUESS who actually had a hand in inventing ALE!
It was a Hollywood actress named Hedy Lamarr!!! She was drop-dead, stunningly gorgeous, but also smart, too. Twenty six and 27 MHZ do, still play a part in this frequency-hopping technique. Hope you enjoyed this bit of trivia.
73
CWM