Amateur Radio - Strange Range
I am slowly preparing a guideline for a possible presentation on Ham radio to an outdoors club. I had mentioned Ham radio and the recent (within the past year) article about W7AU's misfortune in the Montana wilderness. Even with a broken leg he set up camp, ate some food, and set up an antenna for his KX1 and proceeded to call for help.
After viewing the article the idea was brought up to me to do a presentation on Ham radio. If I get it all together and do the presentation my main goals are to give an introduction to what Ham radio is, how we (as outdoor adventurers) can use it, and the other exciting facets of Ham radio - contesting, propagation, DXing, and the rest of the goods.
In explaining Ham radio in the past I have always used the term "unlimited" along with the word "range", or "anywhere in the world", or "anywhere on Earth". The more I got to thinking about it, even though there are variables that must be taken in to account, our range is only physically completely limited by one path, and one path only: Time.
Yes, our "range" depends on the conditions. However, those conditions will allow, at some point in Time, for our signals to get through. The 11 year solar cycle, summer ionization, gray line enhancement, and many other factors do exist. They do physically occur, and it is well-documented throughout the history of Amateur radio. By mapping these phenomena it is possible to forecast being able to get a radio signal from one place to another, and back. All it takes is the right combination of factors at one point in Time.
We can talk across town, across the country, and bridge continents. We can even break through the grasps of our planet and reach satellites, astronauts, and the moon.
Thinking about it further, and perhaps I am reaching a bit deep; is there really a limit to range?
We have been sending out signals from this Earth, as noted in the movie Contact (I believe), for over a hundred years. Yes, movies are not credible, especially for a scientific resource being science fiction. However, there is truth to it - broadcast radio and TV, for the majority, have been around for years. Some of that energy does break through the atmosphere. Then, you have communications uses for radio - even some specifically designed to leave the atmosphere, with the intent to have it come back and receive it - satellites and other space communications.
To add to the mix, the Amateur radio crowd has been using high power and high directivity to send intense signals through the atmosphere to be reflected off the surface of the Moon. Trying to get all of that signal on the moon is like trying to hit a target from 100 yards with a shot gun and keeping all the BB's within the target area. Yeah, the barrel of the gun is pointed at the target and thus that is the direction the projectiles go - but out of all those BB's there is no way even a large percent will get there. Those that miss the target go around and beyond. Where do our signals go? Out in to Space.
Since radio signals travel at the speed of light, and there really isn't a whole lot to stop them, only dissipation by spreading out, they keep on going. Therefore, the first signal to ever to break through the atmosphere is still out there - 50, 60, 70 or however many light-years out, still holding the message and sound it did when it was generated.
Therefore, radio signals, at some location in the Universe, just as with light, does traverse Time itself. Of course, we have no way to communicate through, much less receive, 30 year old signals. If we could, there would be no way to get it back to the place at the same Time of the origin since, as is currently known, time moves forward only.
That would sure be neat if we could!
From an engineering perspective, and thinking back to a speech by Neil Armstrong at which I was present: if you always take half of something, never more, never less, and repeat the process; when do you acquire the whole thing? Mathematically, you don't (1/2, 1/4, 1/8, 1/16, 1/32...). Practically, there is a limit - at some point you loose enough percentage to constitute the whole - for all intensive purposes.
So given that electromagnetic energy (including light) dissipates, at what point, for all intensive purposes, does a signal become nothing? I assume that depends on the frequency, original intensity, and the medium in which it travels or passes through.
If my mind-wondering has any meaning, and if there can be a real-world detectable edge (higher receiver sensitivity = lower detectable edge), it should be possible to figure out how far out in Time a signal, albeit a one-way ride, would be able to be heard.
YAWWWN. Maybe my unconscious mind can work some magic while I sleep and I can unlock some physical mystery... Good night.
After viewing the article the idea was brought up to me to do a presentation on Ham radio. If I get it all together and do the presentation my main goals are to give an introduction to what Ham radio is, how we (as outdoor adventurers) can use it, and the other exciting facets of Ham radio - contesting, propagation, DXing, and the rest of the goods.
In explaining Ham radio in the past I have always used the term "unlimited" along with the word "range", or "anywhere in the world", or "anywhere on Earth". The more I got to thinking about it, even though there are variables that must be taken in to account, our range is only physically completely limited by one path, and one path only: Time.
Yes, our "range" depends on the conditions. However, those conditions will allow, at some point in Time, for our signals to get through. The 11 year solar cycle, summer ionization, gray line enhancement, and many other factors do exist. They do physically occur, and it is well-documented throughout the history of Amateur radio. By mapping these phenomena it is possible to forecast being able to get a radio signal from one place to another, and back. All it takes is the right combination of factors at one point in Time.
We can talk across town, across the country, and bridge continents. We can even break through the grasps of our planet and reach satellites, astronauts, and the moon.
Thinking about it further, and perhaps I am reaching a bit deep; is there really a limit to range?
We have been sending out signals from this Earth, as noted in the movie Contact (I believe), for over a hundred years. Yes, movies are not credible, especially for a scientific resource being science fiction. However, there is truth to it - broadcast radio and TV, for the majority, have been around for years. Some of that energy does break through the atmosphere. Then, you have communications uses for radio - even some specifically designed to leave the atmosphere, with the intent to have it come back and receive it - satellites and other space communications.
To add to the mix, the Amateur radio crowd has been using high power and high directivity to send intense signals through the atmosphere to be reflected off the surface of the Moon. Trying to get all of that signal on the moon is like trying to hit a target from 100 yards with a shot gun and keeping all the BB's within the target area. Yeah, the barrel of the gun is pointed at the target and thus that is the direction the projectiles go - but out of all those BB's there is no way even a large percent will get there. Those that miss the target go around and beyond. Where do our signals go? Out in to Space.
Since radio signals travel at the speed of light, and there really isn't a whole lot to stop them, only dissipation by spreading out, they keep on going. Therefore, the first signal to ever to break through the atmosphere is still out there - 50, 60, 70 or however many light-years out, still holding the message and sound it did when it was generated.
Therefore, radio signals, at some location in the Universe, just as with light, does traverse Time itself. Of course, we have no way to communicate through, much less receive, 30 year old signals. If we could, there would be no way to get it back to the place at the same Time of the origin since, as is currently known, time moves forward only.
That would sure be neat if we could!
From an engineering perspective, and thinking back to a speech by Neil Armstrong at which I was present: if you always take half of something, never more, never less, and repeat the process; when do you acquire the whole thing? Mathematically, you don't (1/2, 1/4, 1/8, 1/16, 1/32...). Practically, there is a limit - at some point you loose enough percentage to constitute the whole - for all intensive purposes.
So given that electromagnetic energy (including light) dissipates, at what point, for all intensive purposes, does a signal become nothing? I assume that depends on the frequency, original intensity, and the medium in which it travels or passes through.
If my mind-wondering has any meaning, and if there can be a real-world detectable edge (higher receiver sensitivity = lower detectable edge), it should be possible to figure out how far out in Time a signal, albeit a one-way ride, would be able to be heard.
YAWWWN. Maybe my unconscious mind can work some magic while I sleep and I can unlock some physical mystery... Good night.
posted by Steve at
11:02 PM
0 Comments:
Post a Comment
Subscribe to Post Comments [Atom]
<< Home