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#111
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On 7/6/2012 11:44 PM, Sal M. O'Nella wrote:
wrote in message . net... On 7/6/2012 3:46 AM, Szczepan Bialek wrote: napisal w wiadomosci Do you agree that such "dipole" is the monopole? S* Absolutely not. tom K0TAR Is this guy the ghost of Allen Funt? He has set up such an improbable situation with his nonsense that we are unable to grasp it, so we suspend disbelief. "Sal" Allen Funt was intelligent. And funny. SB is neither. All he can do is google, copy URLs or parts of articles, then paste. Zero brain activity involved. tom K0TAR |
#112
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On 7/8/2012 4:31 AM, Szczepan Bialek wrote:
napisa³ w wiadomo¶ci ... Szczepan wrote: You should know that the true dipole is directional. Are your "dipoles" directional? Everything build-able is directional, to a greater or lesser degree, when the pattern is viewed in 3 dimensions. tom K0TAR |
#114
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tom wrote:
On 7/8/2012 4:31 AM, Szczepan Bialek wrote: napisa³ w wiadomo¶ci ... Szczepan wrote: You should know that the true dipole is directional. Are your "dipoles" directional? Everything build-able is directional, to a greater or lesser degree, when the pattern is viewed in 3 dimensions. tom K0TAR You want this moron to think in three dimensions when he can't tell the difference between 1 and 2 (monopole/dipole)? |
#115
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![]() napisa³ w wiadomo¶ci ... Szczepan Bialek wrote: "The Hertzian dipole Consider two small spherical conductors connected by a wire. Suppose that electric charge flows periodically back and forth between the spheres." In " NASA" antennas (eg. phase radars) the each "sphere" is fed from special feeder. Phased radars don't use spheres for antennas. Hertz was using the spheres or plates. They both were the ends of the open circuit. The end can be without any "hat". If are the two sphere we have a dipole (Hertzian dipole). In Marconi antenna is only one "sphere". It is the monopole. Do you have exactly the same voltages in the both ends of your "dipole"? S* |
#116
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![]() napisa³ w wiadomo¶ci ... Szczepan Bialek wrote: The braid and the arm are together the counterpoise. No, they are not, you babbling idiot. Have you the same voltages on the braid and on the coax "live" wire? Not without a ballancing device of some sort. Are the same voltages on the counterpoise and on the arm? If not, than you heve the monopole. What an utter idiot; a monopole has one physical element while a dipole has two physical elements. Monopole have always the two elements: the antenna and the counterpoise. That is the meaning of the prefixes "mono", which means one, and "di", which means two. So monopole has the one pole. The end of the counterpoise is not the pole. In your "dipole" the counterpoise is in the form of one elevated radial. S* |
#117
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![]() napisa³ w wiadomo¶ci ... Szczepan Bialek wrote: Monopole antenna: "One side of the antenna feedline is attached to the lower end of the monopole, and the other side is attached to the ground plane, which is often the Earth." Yes, and there in ONE element. Dipole antenna: "A dipole antenna is a straight electrical conductor measuring 1/2 wavelength from end to end and connected at the center to a radio-frequency (RF) feed line. This antenna, also called a doublet, is one of the simplest types of antenna, and constitutes the main RF radiating and receiving element in various sophisticated types of antennas. The dipole is inherently a balanced antenna, because it is bilaterally symmetrical. Ideally, a dipole antenna is fed with a balanced, parallel-wire RF transmission line" Yes, and there are TWO elements. The Hertz dipole was symmetrical. A dipole is symmetrical by definition, idiot. The "dipole" where one element is connected to "live" wire and the second to a "ground" is the monopole. Yours "dipoles" are not symmetrical (electrically0. They are symmetrical mechanically. S* |
#118
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Szczepan Bialek wrote:
The "dipole" where one element is connected to "live" wire and the second to a "ground" is the monopole. It is your misunderstanding that: 1. amateurs always connect coax directly to a dipole. they don't. those that are in the know will use a balun. 2. the braid of the coax is "ground". this is not true. there will be voltage at the braid of the coax at the antenna end when a balun is not used. |
#119
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In message , Rob
writes Szczepan Bialek wrote: The "dipole" where one element is connected to "live" wire and the second to a "ground" is the monopole. It is your misunderstanding that: 1. amateurs always connect coax directly to a dipole. they don't. those that are in the know will use a balun. In the past, many amateurs did connect coax directly to a dipole. The reason is that - on most occasions - it worked perfectly well, and they 'got away with it'. It was only when problems occurred (interference to TV, radio, Hi-Fi etc) that much thought was given to the need for a balun. In modern times, there is a lot more opportunity for amateurs to interfere with - and suffer interference from - all kinds of domestic equipment, and the use of a balun (or twin feeder) has more-or-less become an absolute necessity. 2. the braid of the coax is "ground". this is not true. there will be voltage at the braid of the coax at the antenna end when a balun is not used. Szczepan is obviously making the fundamental mistake of thinking that, because the coax screen is grounded at the transmitter end (or at least connected to the chassis of the transmitter), it is therefore at zero RF potential - and that it is still at RF potential at the far (antenna) end, where it is connected directly to the 'other' leg of the dipole. This is wrong. He is then assuming that if the coax screen is at zero RF potential where it is connected to the other leg of the dipole, then the other leg of the dipole is also at zero RF potential (and doesn't radiate). This is wrong. He is therefore concluding that as both the coax screen and the other leg of the dipole are at zero RF potential, the only part of the antenna system that is 'RF live' is the leg of the dipole which is connected to the inner conductor of the coax - which is what happens with a monopole. As a result, he is then claiming that a dipole is really only a monopole. This is wrong. However, I'm still convinced that Szczepan knows far more about radio than he appears to, and is cunningly trying to get us to explain phenomena which maybe we really don't know as much about as we like to think we do! -- Ian |
#120
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Szczepan Bialek wrote:
napisa? w wiadomo?ci ... Szczepan Bialek wrote: Monopole antenna: "One side of the antenna feedline is attached to the lower end of the monopole, and the other side is attached to the ground plane, which is often the Earth." Yes, and there in ONE element. Dipole antenna: "A dipole antenna is a straight electrical conductor measuring 1/2 wavelength from end to end and connected at the center to a radio-frequency (RF) feed line. This antenna, also called a doublet, is one of the simplest types of antenna, and constitutes the main RF radiating and receiving element in various sophisticated types of antennas. The dipole is inherently a balanced antenna, because it is bilaterally symmetrical. Ideally, a dipole antenna is fed with a balanced, parallel-wire RF transmission line" Yes, and there are TWO elements. The Hertz dipole was symmetrical. A dipole is symmetrical by definition, idiot. The "dipole" where one element is connected to "live" wire and the second to a "ground" is the monopole. The transmission line used to connect to the antenna has absolutely nothing to do with what kind of antenna a particular antenna is. Transmission lines and antennas are two separate things. You are a babbling, ineducable idiot. Yours "dipoles" are not symmetrical (electrically0. They are symmetrical mechanically. ALL of my dipoles ARE electrically symmetrical as they are fed either with balanced transmission line or there is a balancing device between the transmission line and the antenna. How many antennas have you built in your lifetime? |
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