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Part 15 Skywave

R. Fry said:
William C. Walker said:
It is apparent the people that claim to know the laws of Physics are using a flawed system when trying to analyze why or why not a Part 15 AM signal behaves a certain way that defies their view of the laws of Physics.
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The concept in the link posted by William C. Walker even if/when proven as true has nothing to do with the proven physics applying to the performance of Part 15 systems operating in the AM/FM broadcast bands, or any other system radiating/receiving electromagnetic fields.

RF
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I'm aware of that. The point that I am making is that perhaps the laws of physics are not being accurately interpreted by the people that claim to be experts. Technology changes and new discoveries are made to improve upon past inaccuracies in certain fields.
 
Here is a concept that has not even been considered: The "LENS" effect of the ionosphere. It *IS* a curved surface, after all... but it also has "waves" and "wrinkles", just like water. If you take a flashlight under water, and aim it at an upward angle, some of that light WILL reflect back down from the water surface-to-air barrier. Behold, you will see areas of BRIGHTER and DIMMER light, which move with the surface waves. Now, substitute light with RADIO waves, and increase the scale size a few million times...

Here is my point: The signal, albeit WEAK and scattered quite a bit after ascending "free space" the 50 miles or so into the ionosphere... strikes the CURVED surface, which then FOCUSES a reflection back to Earth. Like a satellite dish focuses RF into the feedhorn... the ionosphere focuses the RF across a several kilometer-wide "dish", and aims that focused energy back down... and someone happens to hear it. Possible? Very much so. Likely? No, not really... but the probability is NOT ZERO! :)

Therefore, I believe that while it's EXTREMELY UNLIKELY that someone with a standard radio will receive a legitimate P15 signal via "skip"... IT IS POSSIBLE given the right conditions... and I must say that those conditions DID EXIST at the time this person heard that P15 station from far away.
 
I'll add my almost totally-ignorant-of-engineering opinion here: a highly motivated dx-er with an elaborate set up and just the right atmospheric conditions might make this possible.  The atmosphere can do weird things with signals given the right circumstances.  Case in point: I dx-ed two stations from Miami during a hurricane that I have never been able to get before or since.  It seems the hurricane itself sent the signals my way.  Ducting can do weird things too. One night about 25 years ago, I got literally dozens of FM stations from Georgia to Florida when a big front passed through. Never got any of them before or since. 

Could there have been something really odd one night to focus that very weak part 15 signal enough that someone could pick it up that far away?  I say yes. You may say no and we'll just agree to disagree.  :)
 
Although not the same techniques are used, here's another example of micro-power reaching crazy distances! Using computers at each end, people have been able to send and receive signals ACROSS THE GLOBE, using power as low as the crystal oscillator inside a digital watch! (That whole watch runs on a battery the size of a nickel for more than a year... that's less than a microwatt!)

Their technology uses very slow speed Morse code. A "dit" lasts something like 30 minutes. So, it takes a full day to send only a short word, like a callsign. It works. Google QRSS. :)

If a microwatt can be heard "around the world", then by golly, so can 100 milliwatts, with the right conditions. :)
 
WPHA said:
Although not the same techniques are used, here's another example of micro-power reaching crazy distances! Using computers at each end, people have been able to send and receive signals ACROSS THE GLOBE, using power as low as the crystal oscillator inside a digital watch! (That whole watch runs on a battery the size of a nickel for more than a year... that's less than a microwatt!)

Their technology uses very slow speed Morse code. A "dit" lasts something like 30 minutes. So, it takes a full day to send only a short word, like a callsign. It works. Google QRSS. :)

If a microwatt can be heard "around the world", then by golly, so can 100 milliwatts, with the right conditions. :)
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Oh yes! I heard about this at a ham convention a few weeks ago. Absolutely FACINATING what they're able to do.
 
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