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#51
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Richard Clark, KB7QHC wrote:
"Heinrich Hertz might have something to discuss with you about his experiments." Anyone should be so honored! Heinrich Rudolph Hertz (1857-1894) was a pioneer experimental investigator of electromagnetic (EM or radio) waves, according to B. Whitfield Griffith in "Radio-Electronic Transmission Fundamentals'. Hertz in 1887, eight years after the death of J.C. Maxwell (the predictor of EM waves) proved Maxwell correct. Hertz did so by generating the first man-made EM waves in his laboratory. I believe the Hertz antennas consisted of loops which did not depend on presence of ground for operation. Hertz was able to create a severe electrical disturbance in one loop and across a gap in the second loop a spark would jump. Hertzian radio waves are said to lie between 10 kHz and 30,000 GHz, and probably include the range of Art`s antenna. A Hertz antenna is said to have its resonant frequency determined by its distributed capacitance which varies according to its physical length. Best regards, Richard Harrison, KB5WZI |
#52
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Richard Harrison wrote:
Jim Kelley supplied the URL of Lincoln`s Thanksgiving Day proclamation during the American Civil War. It goes back much before Lincoln. If only President Lincoln had known. He could have saved himself the trouble of proclaiming it. Maybe he would have called it Turkey Day instead - like I do. :-) 73 de jk |
#53
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On 21 Nov, 12:31, (Richard Harrison) wrote:
Richard Clark, KB7QHC wrote: "Heinrich Hertz might have something to discuss with you about his experiments." Anyone should be so honored! Heinrich Rudolph Hertz (1857-1894) was a pioneer experimental investigator of electromagnetic (EM or radio) waves, according to B. Whitfield Griffith in "Radio-Electronic Transmission Fundamentals'. Hertz in 1887, eight years after the death of J.C. Maxwell (the predictor of EM waves) proved Maxwell correct. Hertz did so by generating the first man-made EM waves in his laboratory. I believe the Hertz antennas consisted of loops which did not depend on presence of ground for operation. Hertz was able to create a severe electrical disturbance in one loop and across a gap in the second loop a spark would jump. Hertzian radio waves are said to lie between 10 kHz and 30,000 GHz, and probably include the range of Art`s antenna. Yes it does. But it is only half of the story since it basically is missing half of the circuit which the spark was looking for . As you know a requirement is to keep the LC ratio, so basically he had a tesla coil which is the opposite and was looking for the capacitor When you have both of these THEN you have the "circulating" current which creats full radiation.This circulating current is ofcourse in the form of pulses at twice per period where the spark is one of them that is uncontrolled with respect to the frequency of the circuit It is indicative of the time constant involved which is also a requirement of radiation Close but no cigar. A Hertz antenna is said to have its resonant frequency determined by its distributed capacitance which varies according to its physical length. I would argue with that based on the LC ratio for present day radiators but for Hertz it would be correct since his radiator did not have the inductive storage of energy which was dissipated in a spark and not returned to the capacitor. .. Best regards, Richard Harrison, KB5WZI Best regards Art Unwin ...KB9MZ...xg (uk) |
#54
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Richard Harrison wrote:
Cecil, W5DXP wrote: "A TDR will register reflections both from the feedpoint and the open ends of the antennas." Why reflections from the feedpoint if the antenna matches the feedline? A traditional TDR sends a fast rising step or narrow pulse. The condition for no reflection is that the load impedance equal the line impedance over at least the bandwidth of the energy in the step or pulse. Depending on the TDR system, this could be well into the tens of GHz. Even a very broadband antenna doesn't meet this requirement at the feedpoint, so a reflection will occur. Long ago I looked at a small dipole with a TDR system, and I've seen the same result published several times since. What you see resembles a damped square wave, the general square wave shape being due to multiple reflections from the ends and feedpoint, and the damping due to radiation. The top of each "cycle" of the square wave rises, however, because the impedance of the transmission line formed by the two dipole halves increases in impedance from the center to the ends. Roy Lewallen, W7EL |
#55
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Roy Lewallen, W7EL wrote:
"A traditional TDR sends a fast rising step or narrow pulse. The condition for no reflection is that the load impedance equal the line impedance over at least the bandwidth of the energy in the step or pulse." Explanation from the expert makes it crystal clear. Thank you. Best regards, Richard Harrison, KB5WZI |
#56
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On Wed, 21 Nov 2007 14:17:42 -0800 (PST), art
wrote: Yes it does. But it is only half of the story since it basically is missing half of the circuit which the spark was looking for . As you know a requirement is to keep the LC ratio, so basically he had a tesla coil which is the opposite and was looking for the capacitor Hi Arthur, You really should read some history before re-writing it. Hertz' antenna was a single turn of wire (as was the receiver's). If you cannot figure out how Hertz' antenna resonance was achieved (let me drop the shoe here, and say "in the conventional way"), then you are more than 120 years behind in the game. It really has all been done before. Books have been written about it, several movies too, and perhaps a segment on the Discovery Channel. 73's Richard Clark, KB7QHC |
#57
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On 21 Nov, 19:26, Richard Clark wrote:
On Wed, 21 Nov 2007 14:17:42 -0800 (PST), art wrote: Yes it does. But it is only half of the story since it basically is missing half of the circuit which the spark was looking for . As you know a requirement is to keep the LC ratio, so basically he had a tesla coil which is the opposite and was looking for the capacitor Hi Arthur, You really should read some history before re-writing it. Hertz' antenna was a single turn of wire (as was the receiver's). If you cannot figure out how Hertz' antenna resonance was achieved (let me drop the shoe here, and say "in the conventional way"), then you are more than 120 years behind in the game. It really has all been done before. Books have been written about it, several movies too, and perhaps a segment on the Discovery Channel. 73's Richard Clark, KB7QHC For more than a year you have stated "it" has been done before and none of us know what "it" is. Thus your posts have no meaning to anybody and is why they are seen as not worth while persueing. You are so cryptic that you fool yourself as well as wasting other peoples time. is |
#58
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On Wed, 21 Nov 2007 19:57:57 -0800 (PST), art
wrote: For more than a year you have stated "it" has been done before and none of us know what "it" is. US? You got a mouse in your pocket? Is his name Mickey Gauss? 73's Richard Clark, KB7QHC |
#59
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On 26 Nov, 01:33, "Jimmie D" wrote:
"Richard Clark" wrote in message ... On Wed, 21 Nov 2007 19:57:57 -0800 (PST), art wrote: For more than a year you have stated "it" has been done before and none of us know what "it" is. US? You got a mouse in your pocket? Is his name Mickey Gauss? 73's Richard Clark, KB7QHC In a way I can feel Arts's pain. When I was 13 I thought I had discovered a new way of rectifying AC, too bad the bridge rectifier had already been invented. I was crushed. Jimmie. No. That is just Richard playing word games with his "it" just like Clinton with "is" I say I have invented a 160M antenna that is rotatable and directional and without the requirement of a ground plain. It could have been for a different frequency but I chose the worst case scenario. No, you will have to wait for the PTO to print it before you can duplicate it Now Richard with his word games is playing with the word "it". And he knows full well that hams are not using this antenna design at the present time. The day will come when he has to state what "it" is but rest assured it will not be the rotatable 160 M antenna.It took him and David several months to even acknowledge that you can add a time variable to static law. Now they both insinuate that they knew that all along. In a few more months Richard will conjure up something that fits his present posture. Until then it is word games that insinuate but does not actually state thus his befuddled postings that few understand. Art |
#60
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On Mon, 26 Nov 2007 06:27:22 -0800 (PST), art
wrote: I say I have invented a 160M antenna that is rotatable and directional and without the requirement of a ground plain. Hi Arthur, "It" is called a dipole. 'It" has already been done. There have been extrememly long threads here for weeks discussing this design: Rotatable 200M antennas that are half a meter wide! These rotatable and directional designs have been around since the days of Queen Victoria. It could have been for a different frequency but I chose the worst case scenario. Others figured out how to do "it" too. One of the first was some bumpkin called Hertz. You probably haven't read about him in a book unfortunately. 73's Richard Clark, KB7QHC |
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