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On 4/15/2012 11:28 AM, Channel Jumper wrote:
Well I am going to be unusually kind today, since it is Sunday and also because I am going to show some intelligence here. So everyone listen up - because I am only going to do this one time. How kind of you. I am not going to fight over who invented radio, or the different types of modulation scheme's - since the days of spark gap transmitters. I tried to post some relevant information - but it seemed to get lost in the jumble. The info you posted dealt with mostly mobile applications. Only vaguely relevant to the statement at hand, which was a quote from a long dead radio buoy, stating that no practical wireless system exists, which is not connected to earth. Most of the irrelevant blabber-gab deleted to save bandwidth, except for this one.. There is nothing in outer space for the signals to bounce off of - so they travel millions of miles in just a couple of seconds. That I would like to see, being as it takes light from the sun over eight minutes to travel from the sun, to the earth.. Try about 372,564 miles in two seconds.. Hardly millions.. Or that some ham would be willing to spend 10's of thousands of dollars to buy a transceiver that does the same basic thing as a AM radio you can buy in any Walmart or Goodwill for a couple of bucks. That's about one silly statement, unless the ham plans to do nothing but listen to KTRH all day long. Most use them in other ways, which most all of which the typical Wallace World special could only dream of. I only wish Wallace World sold usable amateur radios for a couple of bucks. I'd have several hundred more radios than I already have. :| When you crank up the power, it allows the person on the other end to use a smaller antenna - hence the people who buys or builds the big towers and the big beam antenna's would think that their investment would allow them global communications on a daily basis - and still we have not gotten past the fact that all reliable communicatiosn is LOS - even 100 years later... Does that mean they are all SOL? The OP wanted to debate the fact that some antenna's works best when we include some type of ground. Yes a good vertical transmitting antenna includes some type of ground to keep the signal from warming the clouds and being wasted. Not all verticals require ground systems, and how did the clouds ever get involved? Seems you may be confusing the benefits of feed line decoupling with the benefits of a radial system under a ground mounted monopole. :/ A beam antenna does not have a physical ground, yet still works - maybe the ground reflections helps the signals to travel further. Then maybe they don't.. Also, some directional arrays do use ground systems, if they are ground mounted. But this statement does not mean Marconi's statement is correct. But we all know that effective communications requires the antenna to be as high as possible. In some cases, it may make no difference how high the antennas are. In others, it may mean a great deal. Only once you get to what is it 38,000 miles one antenna will transmit to one hemisphere - or is it what ever part of the earth you can see and will transmit no further. That is the point of diminishing returns. Maybe so, but there are no structures that high for me to attach an antenna to. And I can't jump that high. ![]() |
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