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#1
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art wrote:
What is the ratio of magnetic electrons emitted from a radiator compared with with the number of electrons emmitted due to current flow? What is the combination ratio required of both types of electrons to form a radiation field? Regards Art You mean the radiation from an antenna driven by a radio transmitter? It doesn't emit electrons, but it does emit photons at that radio frequency. Go find a book on electromagnetism and fields, but be prepared for calculus level math in that book. I took such a class 30 years ago, and got a "C", and remember even less now. A high school physics book might be enough depending on your needs. |
#2
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robert casey wrote:
art wrote: What is the ratio of magnetic electrons emitted from a radiator compared with with the number of electrons emmitted due to current flow? What is the combination ratio required of both types of electrons to form a radiation field? Regards Art You mean the radiation from an antenna driven by a radio transmitter? It doesn't emit electrons, but it does emit photons at that radio frequency. Go find a book on electromagnetism and fields, but be prepared for calculus level math in that book. I took such a class 30 years ago, and got a "C", and remember even less now. A high school physics book might be enough depending on your needs. The current (May/June) issue of QEX contains the article: Electromagnetic Radiation: A Brief Tutorial It contains equations but no calculus that I noticed. "magnetic electrons emitted from a radiator" isn't mentioned, but that isn't a surprise to most people. -- Jim Pennino Remove .spam.sux to reply. |
#3
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On 10 May, 11:45, wrote:
robert casey wrote: art wrote: What is the ratio of magnetic electrons emitted from a radiator compared with with the number of electrons emmitted due to current flow? What is the combination ratio required of both types of electrons to form a radiation field? Regards Art You mean the radiation from an antenna driven by a radio transmitter? It doesn't emit electrons, but it does emit photons at that radio frequency. Go find a book on electromagnetism and fields, but be prepared for calculus level math in that book. I took such a class 30 years ago, and got a "C", and remember even less now. A high school physics book might be enough depending on your needs. The current (May/June) issue of QEX contains the article: Electromagnetic Radiation: A Brief Tutorial It contains equations but no calculus that I noticed. "magnetic electrons emitted from a radiator" isn't mentioned, but that isn't a surprise to most people. -- Jim Pennino Remove .spam.sux to reply.- Hide quoted text - - Show quoted text - Jim, you have no legitamacy in the subject of radiation, your past posts prove that. On top of that you do not talk for most people as you intimate. You haven't yet capitulated on the static subject or negated the truth of the mathematics and examples supplied. Just stating consistently that you can't this or you can't that just doesn't elevate your stature. |
#4
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On 10 May, 12:06, art wrote:
On 10 May, 11:45, wrote: robert casey wrote: art wrote: What is the ratio of magnetic electrons emitted from a radiator compared with with the number of electrons emmitted due to current flow? What is the combination ratio required of both types of electrons to form a radiation field? Regards Art You mean the radiation from an antenna driven by a radio transmitter? It doesn't emit electrons, but it does emit photons at that radio frequency. Go find a book on electromagnetism and fields, but be prepared for calculus level math in that book. I took such a class 30 years ago, and got a "C", and remember even less now. A high school physics book might be enough depending on your needs. The current (May/June) issue of QEX contains the article: Electromagnetic Radiation: A Brief Tutorial It contains equations but no calculus that I noticed. "magnetic electrons emitted from a radiator" isn't mentioned, but that isn't a surprise to most people. -- Jim Pennino Remove .spam.sux to reply.- Hide quoted text - - Show quoted text - Jim, you have no legitamacy in the subject of radiation, your past posts prove that. On top of that you do not talk for most people as you intimate. You haven't yet capitulated on the static subject or negated the truth of the mathematics and examples supplied. Just stating consistently that you can't this or you can't that just doesn't elevate your stature.- Hide quoted text - - Show quoted text - Some have stated that 377 ohms is a ratio. I don't understand that assertion since I understood that a ratio is not confined to a specific unit and in fact does not have units. I am aware that the impedance of a particular atmosphere is 377 ohms but that is certainly not a ratio. Some say one must have a knoweledge of calculus to understand radiation. Another declares he read a book on radiation that did not use calculus which is just as well if one becomes careless with terms such as a ratio. But no matter, this newsgroup is a living example of the use of free speech where amateurs can take on the guise of professionalism despite their lowly education level. |
#5
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art wrote:
I am aware that the impedance of a particular atmosphere is 377 ohms but that is certainly not a ratio. From: http://whatis.techtarget.com/definit...845268,00.html Mathematically, the Zo of free space is equal to the square root of the ratio of the permeability of free space (µo) in henrys per meter (H/m) to the permittivity of free space (o) in farads per meter (F/m): Zo = (µo/o)1/2 = [(1.257 x 10-6 H/m)/(8.85 x 10-12 F/m)]1/2 = 377 ohms (approximately) The exact value of the Zo of free space is 120 pi ohms, where pi is the ratio of the circumference of a circle to its diameter. -- 73, Cecil, w5dxp.com |
#6
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On 10 May, 12:58, Cecil Moore wrote:
art wrote: I am aware that the impedance of a particular atmosphere is 377 ohms but that is certainly not a ratio. From:http://whatis.techtarget.com/definit...845268,00.html Mathematically, the Zo of free space is equal to the square root of the ratio of the permeability of free space (µo) in henrys per meter (H/m) to the permittivity of free space (o) in farads per meter (F/m): Zo = (µo/o)1/2 = [(1.257 x 10-6 H/m)/(8.85 x 10-12 F/m)]1/2 = 377 ohms (approximately) The exact value of the Zo of free space is 120 pi ohms, where pi is the ratio of the circumference of a circle to its diameter. -- 73, Cecil, w5dxp.com O.k. Cecil I will for the moment embrace that a ratio must have a unit of measurement which puts me in line with all the amateurs of this newsgroup (see I am flexible). I will also change from particles now, to electrons and now to protons as requested ( see I am flexible again) For my interest, what is the unit that must be used for the front to back ratio of a directive antenna? Regards Art |
#7
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art wrote:
For my interest, what is the unit that must be used for the front to back ratio of a directive antenna? Power ratios are commonly stated in dB. -- 73, Cecil http://www.w5dxp.com |
#8
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Art wrote:
"For my interest, what is the unit that must be used for front to back ratio of a directive antenna?" I must be an idiot for venturing an answer, but ratios can be just numbers, but numbers have origins. If radiated power in one direction is twice that in another (reference), we can say it has a directive gain of two or we can say it has a 3 dB gain. Front to back ratios have the same origins and units. For legitimacy, Terman says on page 871 of his 1955 opus: "The directive gain can be expressed either as a power ratio, or in terms of the equivalent number of decibels. Best regards, Richard Harrison, KB5WZI |
#9
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"Cecil Moore" wrote in message
t... art wrote: I am aware that the impedance of a particular atmosphere is 377 ohms but that is certainly not a ratio. From: http://whatis.techtarget.com/definit...845268,00.html Mathematically, the Zo of free space is equal to the square root of the ratio of the permeability of free space (µo) in henrys per meter (H/m) to the permittivity of free space (o) in farads per meter (F/m): Zo = (µo/o)1/2 = [(1.257 x 10-6 H/m)/(8.85 x 10-12 F/m)]1/2 = 377 ohms (approximately) The exact value of the Zo of free space is 120 pi ohms, where pi is the ratio of the circumference of a circle to its diameter. -- 73, Cecil, w5dxp.com Also the ratio of E/H. [(V/m)/(A/m)] = [ohms]. Frank |
#10
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Frank's wrote:
Also the ratio of E/H. [(V/m)/(A/m)] = [ohms]. Is that a cause or an effect? :-) -- 73, Cecil http://www.w5dxp.com |
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