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Hopefully not off topic
Whilst trying to source a "digital" TV antenna I came across some with all
external surfaces plastic. One was a small yagi with all external surfaces plastic, hopefully with metal elements embedded. Another a "T" shape made out of plastic conduit with elements inside conduit. My question is how do they work?. If they are detecting electrical fields how does increasing source impedance by 100,s of megohms improve things?. Capacitive coupling, I suppose at the frequencies involved there would be some. If it works as well as all metal why doesn,t every one use it and stop corrosion? Hope this is not too off topic. Many thanks John |
Hopefully not off topic
John wrote:
Whilst trying to source a "digital" TV antenna I came across some with all external surfaces plastic. One was a small yagi with all external surfaces plastic, hopefully with metal elements embedded. Another a "T" shape made out of plastic conduit with elements inside conduit. My question is how do they work?. If they are detecting electrical fields how does increasing source impedance by 100,s of megohms improve things?. Capacitive coupling, I suppose at the frequencies involved there would be some. If it works as well as all metal why doesn,t every one use it and stop corrosion? Hope this is not too off topic. Many thanks John I think we'll leave this one to mr Bialek to answer... |
Hopefully not off topic
John wrote:
Whilst trying to source a "digital" TV antenna I came across some with all external surfaces plastic. One was a small yagi with all external surfaces plastic, hopefully with metal elements embedded. Another a "T" shape made out of plastic conduit with elements inside conduit. My question is how do they work?. If they are detecting electrical fields how does increasing source impedance by 100,s of megohms improve things?. Capacitive coupling, I suppose at the frequencies involved there would be some. If it works as well as all metal why doesn,t every one use it and stop corrosion? Hope this is not too off topic. I'll bite. Look up Yagi. Mr Yagi was an English speaking Japanese graduate student who happened to study antennas in the 1930's under Professor Uda. Unfortunatly for him and history Prof. Uda did not write English, so he left documenting to the world his discoveries, and they have since been know as Yagi antennas. His discovery was that if you take an antenna, say a dipole, and place another element in the correct position, it adds directionality to the antenna. This reduces its ability to receive signals in all directions and increases its ability to receive them in others. (simplifed explanation follows) Research has since shown that a slightly larger element, not connected to the antenna, acts as a reflector and increases directionality in the opposite direction, i.e. it becomes the back of the antenna. A slightly smaller element, also not connected in the right place acts as a director, causing more restriction and more gain in its direction. You get better results by adding directors than reflectors. While the size of the actual antenna element effects the frequency response of the element, (wider elememnts, wider bandwidth), in most cases, it does not matter how big the reflectors and directors are, only their length and position matter. TV antennas are unusal in that they require a very wide bandwith and other designs such as log-periodic antennas are common, but Yagi designs are used for single channel, or single band antennas. So for example, if you wanted to receive all the stations in one direction, you would use a wideband antenna, if you wanted to receive one partictular station, a Yagi for that frequency would be smaller and cheaper. One could make an antenna out of a piece of paper, drawing the elements on it with a conductive pen and it would work. You could figure that out, that a UHF TV signal may fit on an 8 1/2 x 11 paper, but a lower fequency one would need more space and bigger elements. For recepetion, one only has to build an antenna that would survive its location, so for example a UHF antenna made out of a sheet of plastic, or embedded in one would make a good TV antenna near the sea shore. It would at as a flag in the wind, so it may not be as good a choice as you think. Putting it in your attic, might be a good choice. Lots of ham radio antennas have been made from a stick of wood as the beam (the center piece), copper tubing for the driven element (the real antenna part) and coat hanger wire for the passive elements. Geoff. -- Geoffrey S. Mendelson, N3OWJ/4X1GM/KBUH7245/KBUW5379 To put it in terms everyone understands, the US debt is over 150 Facebooks. |
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"John" wrote in message
. au... My question is how do they work?. If they are detecting electrical fields how does increasing source impedance by 100,s of megohms improve things?. Pardon? The coating or conduit shouldn't affect the impedance of the antenna. The radio signal should pass through the plastic and hit the metal antenna element. Are these antennas intended for indoor use where the plastic coating is for decorative effect? If the antennas are intended for outdoor use then substantial coating or conduiting will increase the wind loading of the antenna It also needs to be u/v stable. Regards, Ian. |
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Ian wrote:
"John" wrote in message . au... My question is how do they work?. If they are detecting electrical fields how does increasing source impedance by 100,s of megohms improve things?. Pardon? The coating or conduit shouldn't affect the impedance of the antenna. The radio signal should pass through the plastic and hit the metal antenna element. Apparently you have missed the interesting discussions with our Polish friend. |
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On Mon, 28 May 2012 16:36:56 +1000, "John"
wrote: Whilst trying to source a "digital" TV antenna There's no such thing as a digital antenna or HDTV antenna. There's nothing specific in the construction or design of the antenna that will make it better or worse for receiving digital or HDTV signals, as opposed to analog or digital signals. Modulation methods do not affect antenna performance (unless you're using very wide band modulation). I came across some with all external surfaces plastic. One was a small yagi with all external surfaces plastic, hopefully with metal elements embedded. Another a "T" shape made out of plastic conduit with elements inside conduit. URL? Picture? Vendor name? Clues? Try not to be so vague. My question is how do they work?. Badly. A "small" antenna always involves some manner of compromise. It can be bandwidth, gain, efficiency, or all of these. If they are detecting electrical fields how does increasing source impedance by 100,s of megohms improve things?. It doesn't improve anything. Antennas much be matched to their loads. If you're plugging this contrivance into a 75 ohm TV receiver, then you'll need some means of matching the 100's of Mohms to 75 ohms. Otherwise, you will have a bad case of mismatch loss. In many cases, such mismatch loss can be tolerated, but not for VHF/UHF TV. Capacitive coupling, I suppose at the frequencies involved there would be some. Oh? There's magic involved. No coax or twinlead cable? It just capacitively couples the antenna to the receiver. Truly amazing. If it works as well as all metal why doesn,t every one use it and stop corrosion? Because I have not clue what "it" is. It "it" a piece of wire shoved into a soda straw size pipe, an aluminum tubing antenna spray painted with plastic, or a PCV schedule 40 contrivance with a wire inside? Please try to be more specific in your descriptions. Hope this is not too off topic. It sucks. No numbers, clue clues, no specifics, nothing new, no interest, and very little entertainment value. Many thanks One would be sufficient. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
Hopefully not off topic
"John" napisa³ w wiadomo¶ci . au... Whilst trying to source a "digital" TV antenna I came across some with all external surfaces plastic. One was a small yagi with all external surfaces plastic, hopefully with metal elements embedded. Another a "T" shape made out of plastic conduit with elements inside conduit. My question is how do they work?. If they are detecting electrical fields how does increasing source impedance by 100,s of megohms improve things?. Capacitive coupling, I suppose at the frequencies involved there would be some. Yes. The frequency do the work. Rob wrote: "Apparently you have missed the interesting discussions with our Polish friend." It was not the discussion. I only citate the Giants: "In 1867 Lorenz wrote: " Ludvig Valentin Lorenz, "On the identity of the vibrations of light with electrical currents," Philosophical Magazine, Vol. 34, 1867, p. 287-301" http://books.google.pl/books?id=caJd...page&q&f=false On p. 301 he wrote: "The present general opinion regards light as consisting of backward and forward motions of particles of aether." If this were the case the electrical current would be the progressive motion of the aether in the direction of the electrical current." In today's words: "Light is the oscillatory flow of electrons". So no problem for electrons to flow through the plastic if it is matched to the frequencies. For example,You must use the different type of glass for different wave length. The ice is O.K. for the RF but the water not. If it works as well as all metal why doesn,t every one use it and stop corrosion? Hope this is not too off topic. It is too off the teaching programs. S* |
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Szczepan Bialek wrote:
It was not the discussion. I only citate the Giants: You only regurgitate very old writtings, many on which have been shown to be either incomplete or outright incorrect in light of modern research. This is usually followed by an out of context snippet from Wiki that is totally misinterpreted. Go babble your nonsense somewhere else. |
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On Mon, 28 May 2012 19:06:03 +0200, "Szczepan Bialek"
wrote: Whilst trying to source a "digital" TV antenna I came across some with all external surfaces plastic. In today's words: "Light is the oscillatory flow of electrons". So no problem for electrons to flow through the plastic if it is matched to the frequencies. For example,You must use the different type of glass for different wave length. The ice is O.K. for the RF but the water not. I believe he said plastic, not glass or ice. Is your theory that if you repeat the same garbage over and over, eventually someone will believe it? I might as well be part of the problem, instead of the solution. Adding to your electron belching antenna theory, such antennas should gain and lose mass as they transmit and receive electrons. If we have (for example), an antenna with 1A of RF current, that's equal to 1 coulomb/second. 1 coulomb is: 6.24x10^18 electrons which should be belching: 9.11*10^-29 g/electron * 6.25*10^18 coulombs/sec = 5.69*10^-9 grams/sec If your bogus theory is correct, you should be able to weigh your antenna and see it loses some mass in transmit, and gains some in receive. Garbage in, Science out. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
Hopefully not off topic
Many thanks for your time Gents, The antennas were intended for outdoor use
and constant handling. being encased in hard plastic obviously enhances those functions. My experience has been at the other end of the spectrum so to speak and I (incorrectly) assumed an antenna picks up an electrical signal. Putting a layer of insulating plastic on it seemed contradictory. If antenna is detecting magnetic signals obviously a different story. When I mentioned impedance I mislead you. Wasnt referring to antenna impedance but the impedance looking back form the recieving antenna to the signal source ( thats what us old analogue designers do, Norton/Thevenin equivalent circuits etc !!!!) and the effect on that a layer of plastic has. Your combined efforts have answered a lot of my questions, thanks for your time. Cheers John "Rob" wrote in message ... Ian wrote: "John" wrote in message . au... My question is how do they work?. If they are detecting electrical fields how does increasing source impedance by 100,s of megohms improve things?. Pardon? The coating or conduit shouldn't affect the impedance of the antenna. The radio signal should pass through the plastic and hit the metal antenna element. Apparently you have missed the interesting discussions with our Polish friend. |
Hopefully not off topic
"Szczepan Bialek" wrote in message
... It was not the discussion. I only citate the Giants: "In 1867 Lorenz wrote: " Ludvig Valentin Lorenz, "On the identity of the vibrations of light with electrical currents," Philosophical Magazine, Vol. 34, 1867, p. 287-301" http://books.google.pl/books?id=caJd...page&q&f=false On p. 301 he wrote: "The present general opinion regards light as consisting of backward and forward motions of particles of aether." If this were the case the electrical current would be the progressive motion of the aether in the direction of the electrical current." Note that it reads "... The PRESENT general OPINION ...". That was in 1867 and was an opinion so presumably it was neither a theory nor a proven fact. We have the benefit of research made over the intervening 145 years. It is probably unwise to quote from books / articles / papers if you do not understand them. |
Hopefully not off topic
On 5/28/2012 12:06 PM, Szczepan Bialek wrote:
napisa³ w wiadomo¶ci . au... Whilst trying to source a "digital" TV antenna I came across some with all external surfaces plastic. One was a small yagi with all external surfaces plastic, hopefully with metal elements embedded. Another a "T" shape made out of plastic conduit with elements inside conduit. My question is how do they work?. If they are detecting electrical fields how does increasing source impedance by 100,s of megohms improve things?. Capacitive coupling, I suppose at the frequencies involved there would be some. Yes. The frequency do the work. Rob wrote: "Apparently you have missed the interesting discussions with our Polish friend." It was not the discussion. I only citate the Giants: "In 1867 Lorenz wrote: " Ludvig Valentin Lorenz, "On the identity of the vibrations of light with electrical currents," Philosophical Magazine, Vol. 34, 1867, p. 287-301" http://books.google.pl/books?id=caJd...page&q&f=false On p. 301 he wrote: "The present general opinion regards light as consisting of backward and forward motions of particles of aether." If this were the case the electrical current would be the progressive motion of the aether in the direction of the electrical current." In today's words: "Light is the oscillatory flow of electrons". So no problem for electrons to flow through the plastic if it is matched to the frequencies. For example,You must use the different type of glass for different wave length. The ice is O.K. for the RF but the water not. If it works as well as all metal why doesn,t every one use it and stop corrosion? Hope this is not too off topic. It is too off the teaching programs. S* Please tell us what meds you are on. That would help us understand your theories. Michael |
Hopefully not off topic
"Jeff Liebermann" napisal w wiadomosci ... On Mon, 28 May 2012 19:06:03 +0200, "Szczepan Bialek" wrote: Whilst trying to source a "digital" TV antenna I came across some with all external surfaces plastic. In today's words: "Light is the oscillatory flow of electrons". So no problem for electrons to flow through the plastic if it is matched to the frequencies. For example,You must use the different type of glass for different wave length. The ice is O.K. for the RF but the water not. I believe he said plastic, not glass or ice. Is your theory that if you repeat the same garbage over and over, eventually someone will believe it? I might as well be part of the problem, instead of the solution. Adding to your electron belching antenna theory, such antennas should gain and lose mass as they transmit and receive electrons. If we have (for example), an antenna with 1A of RF current, that's equal to 1 coulomb/second. 1 coulomb is: 6.24x10^18 electrons which should be belching: 9.11*10^-29 g/electron * 6.25*10^18 coulombs/sec = 5.69*10^-9 grams/sec If your bogus theory is correct, you should be able to weigh your antenna and see it loses some mass in transmit, and gains some in receive. " Inelectronic circuit theory, a "ground" is usually idealized as an infinite source or sink for charge, which can absorb an unlimited amount of current without changing its potential. " All antennas are grounded and you should be able to weigh the Earth because it gain and lose mass as they transmit and receive electrons" S* |
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Szczepan Bialek wrote:
" Inelectronic circuit theory, a "ground" is usually idealized as an infinite source or sink for charge, which can absorb an unlimited amount of current without changing its potential. " The key phrase here is "usually idealized"; there are many examples of systems that don't have anything that could even remotely be considered a "ground". All antennas are grounded Totally false. You are a babbling idiot. |
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On Tue, 29 May 2012 19:12:00 +0200, "Szczepan Bialek"
wrote: " Inelectronic circuit theory, a "ground" is usually idealized as an infinite source or sink for charge, which can absorb an unlimited amount of current without changing its potential. " What does this have to do with measuring the weight change in an antenna that allegedly is transmitting electrons? Electrons have mass. Transmit enough of them and you'll loose mass. Receive enough electrons, and your mythical antenna should gain mass. Also, if the earth is absorbing your electrons, something should be gaining a rather large positive charge as a result of the transmission. Where is the positive charge? While we're at it, there are many ways to detect electrons. One of them is with a phosophor screen, that will light up when hit by electrons. Some how, waving my HT near the phosphor screen of my oscilloscope fails to detect your alleged electrons. Could you perhaps offer a better way to detect the electrons allegedly radiating from an antenna? All antennas are grounded and you should be able to weigh the Earth because it gain and lose mass as they transmit and receive electrons" I see. If I'm standing on the ground, I can't be weighed. Well, my bathroom scale is sitting on the ground and works just fine measuring my weight. My HT antenna isn't grounded. Neither are any of the dipoles on my roof. I presume you're suggesting that they don't work. Now, that we have the requisite science fiction out of the way, could I trouble you to answer my original question. Is your theory that if you repeat the same garbage over and over, eventually someone will believe it? -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
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"Szczepan Bialek" wrote in message ... All antennas are grounded and you should be able to weigh the Earth because it gain and lose mass as they transmit and receive electrons" S* It is incorrect to say that all aerials are grounded. Dipoles, quads and yagis aren't grounded. |
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On 5/29/2012 5:32 PM, Ian wrote:
"Szczepan wrote in message ... All antennas are grounded and you should be able to weigh the Earth because it gain and lose mass as they transmit and receive electrons" S* It is incorrect to say that all aerials are grounded. Dipoles, quads and yagis aren't grounded. And neither are spacecraft antennas no matter what the type. tom K0TAR |
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On 28 May 2012 07:39:06 GMT, Rob wrote:
John wrote: Whilst trying to source a "digital" TV antenna I came across some with all external surfaces plastic. One was a small yagi with all external surfaces plastic, hopefully with metal elements embedded. Another a "T" shape made out of plastic conduit with elements inside conduit. My question is how do they work?. If they are detecting electrical fields how does increasing source impedance by 100,s of megohms improve things?. Capacitive coupling, I suppose at the frequencies involved there would be some. If it works as well as all metal why doesn,t every one use it and stop corrosion? Hope this is not too off topic. Many thanks John I think we'll leave this one to mr Bialek to answer... Hahahaa, yes, and it worked :-) w. |
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"tom" napisal w wiadomosci . net... On 5/29/2012 5:32 PM, Ian wrote: "Szczepan wrote in message ... All antennas are grounded and you should be able to weigh the Earth because it gain and lose mass as they transmit and receive electrons" S* It is incorrect to say that all aerials are grounded. Dipoles, quads and yagis aren't grounded. And neither are spacecraft antennas no matter what the type. The Earth is in space and the spacecraft also. The same is with aircrafts and autos. All transmitters and receivers are connected with the mass. S* |
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"Jeff Liebermann" napisal w wiadomosci ... On Tue, 29 May 2012 19:12:00 +0200, "Szczepan Bialek" wrote: " Inelectronic circuit theory, a "ground" is usually idealized as an infinite source or sink for charge, which can absorb an unlimited amount of current without changing its potential. " What does this have to do with measuring the weight change in an antenna that allegedly is transmitting electrons? Electrons have mass. Transmit enough of them and you'll loose mass. Receive enough electrons, and your mythical antenna should gain mass. Radio transmitter is an electron pump. But without the "infinite source or sink for charge" it do not work. Also, if the earth is absorbing your electrons, something should be gaining a rather large positive charge as a result of the transmission. Where is the positive charge? Without the "infinite source or sink for charge" a transmitter is gaining a rather large positive charge. While we're at it, there are many ways to detect electrons. One of them is with a phosophor screen, that will light up when hit by electrons. Some how, waving my HT near the phosphor screen of my oscilloscope fails to detect your alleged electrons. Could you perhaps offer a better way to detect the electrons allegedly radiating from an antenna? Tesla made the electron beam and next the X-rays. All antennas are grounded and you should be able to weigh the Earth because it gain and lose mass as they transmit and receive electrons" I see. If I'm standing on the ground, I can't be weighed. Well, my bathroom scale is sitting on the ground and works just fine measuring my weight. My HT antenna isn't grounded. Neither are any of the dipoles on my roof. I presume you're suggesting that they don't work. They are connected to the mass (chassis). Now, that we have the requisite science fiction out of the way, could I trouble you to answer my original question. Is your theory that if you repeat the same garbage over and over, eventually someone will believe it? It is theory of Faraday, Lorenz, Marconi, Tesla and Dirac. Who is the authors of yours? S* |
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Szczepan Bialek wrote:
Also, if the earth is absorbing your electrons, something should be gaining a rather large positive charge as a result of the transmission. Where is the positive charge? Without the "infinite source or sink for charge" a transmitter is gaining a rather large positive charge. It is a pity that you are not a radio amateur yourself. If so, you could see with your own eyes (or feel with your own hands) that this is not true, and so the whole theory is incorrect. But maybe you have a cellphone. Try making a long call while you stand on one of those glass tables that they use in static electricity experiments. See if you develop a positive charge while making that call. (and not doing other things like stroking your cat) |
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"Szczepan Bialek" wrote in message
... All transmitters and receivers are connected with the mass. S* Mine aren't. The way you talk about radio reminds me of a friend who used crystal sets back in the 1920s. Fortunately, hew was able to learn modern radio theory and practise. I've a recollection that you've posted your views onto this newsgroup a few weeks ago. I guess that asking you to disregard 19th century understanding and learn 20th and 21st century understanding is probably an unproductive approach. Regards, Ian. |
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Szczepan Bialek wrote:
"Jeff Liebermann" napisal w wiadomosci ... On Tue, 29 May 2012 19:12:00 +0200, "Szczepan Bialek" wrote: " Inelectronic circuit theory, a "ground" is usually idealized as an infinite source or sink for charge, which can absorb an unlimited amount of current without changing its potential. " What does this have to do with measuring the weight change in an antenna that allegedly is transmitting electrons? Electrons have mass. Transmit enough of them and you'll loose mass. Receive enough electrons, and your mythical antenna should gain mass. Radio transmitter is an electron pump. No, it is not. You are an idiot. But without the "infinite source or sink for charge" it do not work. Yes, it does. You are an idiot. Also, if the earth is absorbing your electrons, something should be gaining a rather large positive charge as a result of the transmission. Where is the positive charge? Without the "infinite source or sink for charge" a transmitter is gaining a rather large positive charge. No, it does not. You are an idiot. While we're at it, there are many ways to detect electrons. One of them is with a phosophor screen, that will light up when hit by electrons. Some how, waving my HT near the phosphor screen of my oscilloscope fails to detect your alleged electrons. Could you perhaps offer a better way to detect the electrons allegedly radiating from an antenna? Tesla made the electron beam and next the X-rays. Irrelevant babble. You are an idiot. All antennas are grounded and you should be able to weigh the Earth because it gain and lose mass as they transmit and receive electrons" I see. If I'm standing on the ground, I can't be weighed. Well, my bathroom scale is sitting on the ground and works just fine measuring my weight. My HT antenna isn't grounded. Neither are any of the dipoles on my roof. I presume you're suggesting that they don't work. They are connected to the mass (chassis). Many things do not have a chassis or anything that could even remotely be called a chassis. You are an idiot. Now, that we have the requisite science fiction out of the way, could I trouble you to answer my original question. Is your theory that if you repeat the same garbage over and over, eventually someone will believe it? It is theory of Faraday, Lorenz, Marconi, Tesla and Dirac. No, it is not. You are an idiot. Who is the authors of yours? S* Modern science. And you are an idiot. |
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Szczepan Bialek wrote:
"tom" napisal w wiadomosci . net... On 5/29/2012 5:32 PM, Ian wrote: "Szczepan wrote in message ... All antennas are grounded and you should be able to weigh the Earth because it gain and lose mass as they transmit and receive electrons" S* It is incorrect to say that all aerials are grounded. Dipoles, quads and yagis aren't grounded. And neither are spacecraft antennas no matter what the type. The Earth is in space and the spacecraft also. The same is with aircrafts and autos. All transmitters and receivers are connected with the mass. S* No, they are not. You are a babbling idiot. |
Quote:
Radio waves in front of the person is radiated, radio waves behind the person is blocked to a small extent because of the water in the persons body. This is the reason why Rabbit Ears antenna's do not work in concrete apartment buildings with people moving around the room. The person who is walking around blocks some of the reception - especially in the higher frequency ranges because anything one or more wavelengths in size can and will block a signal. I'm surprised that no one caugth the foopaugh that the origional answer giver had made when he described how a antenna works. The reflector has to be a certain size for a certain wavelength and there is only one driven element. The other elements - also known as directors - gathers the signal and directs them backwards in the array towards the reflector. Each director gathers the same amount of signal as a dipole and each director adds gain to the antenna at the expense of beam width. The only way to increase gain is to give up something somewhere else. If you stack two antenna's one above the other - one wavelength apart - and build phasing lines, each antenna will only agument the other by a gain factor of 2.85 - reguardless of how much gain the origional antenna had. If you stack two beam antenna's, one or more wavelengths apart - the apature becomes smaller - hence if you put enough of them together, it is as if you were trying to look through a straw while driving an automobile. The beam width becomes very narrow, while increasing forward gain to the point of infany. With a UHF signal - eventually when it runs out of things to bounce off of - it just travels in a straight line - out into space, never to be recovered again. I think the OP was asking about receiving antenna's and not transmitting antenna's. A receiving antenna - works best when it is cut to one individual frequency, but those antenna's tends to be more expensive, not less, because they have to be purpose built. The size and spacing has to be more exact to get the results the buyer is looking for. While a VHF antenna, with the use of phasing lines, a person can make a very broadbanded antenna and it will still work up to the length of the longest combined element. When the elements are too long, the antenna can look back through the array and can match the wavelength to the elements in the array... |
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I was sort of hoping you might be able to
give us a Make and/or Model number so we could have a peek at it (assuming we could find it on the net somewhere).. Irv VE6BP "John" wrote in message . au... Many thanks for your time Gents, The antennas were intended for outdoor use and constant handling. being encased in hard plastic obviously enhances those functions. My experience has been at the other end of the spectrum so to speak and I (incorrectly) assumed an antenna picks up an electrical signal. Putting a layer of insulating plastic on it seemed contradictory. If antenna is detecting magnetic signals obviously a different story. When I mentioned impedance I mislead you. Wasnt referring to antenna impedance but the impedance looking back form the recieving antenna to the signal source ( thats what us old analogue designers do, Norton/Thevenin equivalent circuits etc !!!!) and the effect on that a layer of plastic has. Your combined efforts have answered a lot of my questions, thanks for your time. Cheers John "Rob" wrote in message ... Ian wrote: "John" wrote in message . au... My question is how do they work?. If they are detecting electrical fields how does increasing source impedance by 100,s of megohms improve things?. Pardon? The coating or conduit shouldn't affect the impedance of the antenna. The radio signal should pass through the plastic and hit the metal antenna element. Apparently you have missed the interesting discussions with our Polish friend. |
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On Wed, 30 May 2012 09:46:49 +0200, "Szczepan Bialek"
wrote: Radio transmitter is an electron pump. Prove it. Show me a way you can detect your mythical electrons coming off the antenna. Or better yet, explain to me why common methods of detecting electrons (fluorescence, phosphorescence, Wilson cloud chamber, electrometer, electroscope, etc) fail to detect your mythical electrons. But without the "infinite source or sink for charge" it do not work. How large is infinite? Does that mean that radio only works when I can't measure it? Without the "infinite source or sink for charge" a transmitter is gaining a rather large positive charge. Amazing. I put my voltmeter on the case of my HT, and there's no DC voltage when transmitting. Same with various HF transmitters. Perhaps my radio is not infinite enough. Tesla made the electron beam and next the X-rays. Electron beams (cathode rays) were discovered by Johann Hittorf in 1869. http://en.wikipedia.org/wiki/Cathode_ray X-rays were correctly described by Wilhelm Röntgen in 1895. http://en.wikipedia.org/wiki/X-ray Please have you history recalibrated. They are connected to the mass (chassis). Where is the chassis on my HT, TV antenna, dipole, satellite antenna, and other antennas that are not grounded? They seem to work equally well with metallic, insulating, and unsupported mounting arrangements. Also, without I ground, I presume aircraft communications also does not work? Now, that we have the requisite science fiction out of the way, could I trouble you to answer my original question. Is your theory that if you repeat the same garbage over and over, eventually someone will believe it? It is theory of Faraday, Lorenz, Marconi, Tesla and Dirac. Some of their early guesses were wrong. It was bad enough that when Lee De Forest had to defend his patents in court, he could not explain how they worked. I don't care if your theory came directly from the radio gods themselves. If your theory cannot stand up to simple scrutiny and real world examples, then it's garbage, no matter from where you excavated it. Anyway, you didn't answer my question (3rd try). Do you believe that repeating the same wrong theory over and over will somehow make it correct? Or perhaps your plan is to wear everyone down with your one line incorrect and unsubstantiated claims, in the hope that we will become tired of your games and go away? Or, are you simply craving for attention? Who is the authors of yours? I haven't presented a theory. I've only shot holes in your theory. I don't need the testimony of dead scientists to demonstrate that an ungrounded antenna still functions and that antennas do not belch electons. Incidentally, if you had a clue, which you apparently do not, you might read up on photons, which are the carriers of electromagnetic force, including RF. http://en.wikipedia.org/wiki/Photon -- # Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060 # 831-336-2558 # http://802.11junk.com # http://www.LearnByDestroying.com AE6KS |
Hopefully not off topic
On Wed, 30 May 2012 09:08:04 +0200, "Szczepan Bialek"
wrote: And neither are spacecraft antennas no matter what the type. The Earth is in space and the spacecraft also. The earth and spacecraft are floating around in a vacuum, same as between your ears. I think you'll find it rather difficult to demonstrate a conduction path through a vacuum for your grounded antenna theory. Besides, if outer space did provide a conduction path, it would also short out the antenna elements. The same is with aircrafts and autos. Aircraft and autos do not operate in outer space. All transmitters and receivers are connected with the mass. What mass of outer space? There is roughly 1 hydrogen atom per cubic centimeter in outer space. That's not much mass and certainly not enough to ionize and produce a conductive path. -- # Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060 # 831-336-2558 # http://802.11junk.com # http://www.LearnByDestroying.com AE6KS |
Hopefully not off topic
Gents,
Sorry about delay in getting back. After I sent first message my ISP fell off the perch and only now has come back on. Funny how you can get a response from a voluntary organisation within hours but somebody you have a contract with takes days!. I havnt read all your replies yet but will do now, sounds from the numbers there is a controversy. Once again thank you for your expertise. Regards John "Boomer" wrote in message ... On 5/28/2012 12:06 PM, Szczepan Bialek wrote: napisa³ w wiadomo¶ci . au... Whilst trying to source a "digital" TV antenna I came across some with all external surfaces plastic. One was a small yagi with all external surfaces plastic, hopefully with metal elements embedded. Another a "T" shape made out of plastic conduit with elements inside conduit. My question is how do they work?. If they are detecting electrical fields how does increasing source impedance by 100,s of megohms improve things?. Capacitive coupling, I suppose at the frequencies involved there would be some. Yes. The frequency do the work. Rob wrote: "Apparently you have missed the interesting discussions with our Polish friend." It was not the discussion. I only citate the Giants: "In 1867 Lorenz wrote: " Ludvig Valentin Lorenz, "On the identity of the vibrations of light with electrical currents," Philosophical Magazine, Vol. 34, 1867, p. 287-301" http://books.google.pl/books?id=caJd...page&q&f=false On p. 301 he wrote: "The present general opinion regards light as consisting of backward and forward motions of particles of aether." If this were the case the electrical current would be the progressive motion of the aether in the direction of the electrical current." In today's words: "Light is the oscillatory flow of electrons". So no problem for electrons to flow through the plastic if it is matched to the frequencies. For example,You must use the different type of glass for different wave length. The ice is O.K. for the RF but the water not. If it works as well as all metal why doesn,t every one use it and stop corrosion? Hope this is not too off topic. It is too off the teaching programs. S* Please tell us what meds you are on. That would help us understand your theories. Michael |
Hopefully not off topic
On 5/30/2012 12:42 PM, Channel Jumper wrote:
'Jeff Liebermann[_2_ Wrote: ;791197']On Tue, 29 May 2012 19:12:00 +0200, "Szczepan Bialek" wrote: My HT antenna isn't grounded. Neither are any of the dipoles on my roof. I presume you're suggesting that they don't work. -- With a Hand Held Radio - the person holding the transceiver is the ground plane. Because the human body is comprised mainly of water, it acts like the missing half of the antenna. Radio waves in front of the person is radiated, radio waves behind the person is blocked to a small extent because of the water in the persons body. This is the reason why Rabbit Ears antenna's do not work in concrete apartment buildings with people moving around the room. The person who is walking around blocks some of the reception - especially in the higher frequency ranges because anything one or more wavelengths in size can and will block a signal. Not quite right, since you don't have to actually "block" the signal for it to happen, but Mr. Blaupunkt wouldn't have a clue anyway. It's more about the whole wavefront, amplitude of the parts of same, phase, and interaction with the surrounding conductive and absorptive environment. Some of which can be alive, filled with salt water, and move. tom K0TAR |
Hopefully not off topic
"Jeff Liebermann" wrote in message ... On Wed, 30 May 2012 09:08:04 +0200, "Szczepan Bialek" wrote: And neither are spacecraft antennas no matter what the type. # Jeff Why does anyone answer Skeezix Blutarsky? |
Hopefully not off topic-link
Here is the 'T" antenna I referred to. It is totally plastic.
http://www.happywanderer.net.au/page...9&parent2id=24 If link doesnt work the website is www.happywanderer.net.au and the image is on first screen. The totally plastic covered yagi I saw was somewhere in ebay. I,ll see if I can find it again. Regards John "John" wrote in message . au... Whilst trying to source a "digital" TV antenna I came across some with all external surfaces plastic. One was a small yagi with all external surfaces plastic, hopefully with metal elements embedded. Another a "T" shape made out of plastic conduit with elements inside conduit. My question is how do they work?. If they are detecting electrical fields how does increasing source impedance by 100,s of megohms improve things?. Capacitive coupling, I suppose at the frequencies involved there would be some. If it works as well as all metal why doesn,t every one use it and stop corrosion? Hope this is not too off topic. Many thanks John |
Hopefully not off topic-link
And the yagi,
http://www.ebay.com.au/itm/Caravan-R...e m2ebd055150 The argument I seemed to have inadvertently triggered reminds me of disgreement I had about 40 years ago describing Op Amp inputs as virtual earths. Odd how equally intelligent and educated people can look at things differently. Cheeers John "John" wrote in message . au... Here is the 'T" antenna I referred to. It is totally plastic. http://www.happywanderer.net.au/page...9&parent2id=24 If link doesnt work the website is www.happywanderer.net.au and the image is on first screen. The totally plastic covered yagi I saw was somewhere in ebay. I,ll see if I can find it again. Regards John "John" wrote in message . au... Whilst trying to source a "digital" TV antenna I came across some with all external surfaces plastic. One was a small yagi with all external surfaces plastic, hopefully with metal elements embedded. Another a "T" shape made out of plastic conduit with elements inside conduit. My question is how do they work?. If they are detecting electrical fields how does increasing source impedance by 100,s of megohms improve things?. Capacitive coupling, I suppose at the frequencies involved there would be some. If it works as well as all metal why doesn,t every one use it and stop corrosion? Hope this is not too off topic. Many thanks John |
Hopefully not off topic-link
On 5/30/2012 10:21 PM, John wrote:
Here is the 'T" antenna I referred to. It is totally plastic. http://www.happywanderer.net.au/page...9&parent2id=24 If link doesnt work the website is www.happywanderer.net.au and the image is on first screen. The totally plastic covered yagi I saw was somewhere in ebay. I,ll see if I can find it again. Regards John I liked the reflector screen on the HW-DT8. It's appears just a bit sparse for the frequencies it's supposed to cover. Other than that the driven part is kind of interesting. If it's reasonably priced enough and shipping isn't out of line I may order one just to see what mischief they are up to. tom K0TAR Link to the antenna I referenced. http://www.happywanderer.net.au/page...9&parent2id=71 And of course it will give me a nice new antenna to perform weight and charge measurements on. Can't use an old one. See, when the antenna gets used more and more it gets tired because of electron loss. You have to watch your transmit and receive balance. If you don't you will end up with too few electrons around, which makes for an increase in transmit resistance. Some people think it's impedance, but they don't know it's just because you haven't got the right length coax. And the other way around, if you receive all the time you eventually fill the electron sump, and the antenna must be discarded unless you can get a good electron sump pump for cheap. Funny thing, that's why the old AM and FM radios wore out - they were full. |
Hopefully not off topic
On Wed, 30 May 2012 20:00:55 -0700, "Sal M. O'Nella"
wrote: Why does anyone answer Skeezix Blutarsky? Because I'm terrible at resisting temptation. If someone wants to make themselves a target, it's far too tempting to take a few shots at the target. Also, I enjoy reading (and writing) science fiction. However, the real reason is that I haven't seen any decent antenna related discussions in this newsgroup for a long time. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
Hopefully not off topic-link
Its why you should never leave a powerpoint switched on. You end up with a
heap of electrons on the floor. And a hole under the neutral hole. "tom" wrote in message . net... On 5/30/2012 10:21 PM, John wrote: Here is the 'T" antenna I referred to. It is totally plastic. http://www.happywanderer.net.au/page...9&parent2id=24 If link doesnt work the website is www.happywanderer.net.au and the image is on first screen. The totally plastic covered yagi I saw was somewhere in ebay. I,ll see if I can find it again. Regards John I liked the reflector screen on the HW-DT8. It's appears just a bit sparse for the frequencies it's supposed to cover. Other than that the driven part is kind of interesting. If it's reasonably priced enough and shipping isn't out of line I may order one just to see what mischief they are up to. tom K0TAR Link to the antenna I referenced. http://www.happywanderer.net.au/page...9&parent2id=71 And of course it will give me a nice new antenna to perform weight and charge measurements on. Can't use an old one. See, when the antenna gets used more and more it gets tired because of electron loss. You have to watch your transmit and receive balance. If you don't you will end up with too few electrons around, which makes for an increase in transmit resistance. Some people think it's impedance, but they don't know it's just because you haven't got the right length coax. And the other way around, if you receive all the time you eventually fill the electron sump, and the antenna must be discarded unless you can get a good electron sump pump for cheap. Funny thing, that's why the old AM and FM radios wore out - they were full. |
Hopefully not off topic
John wrote:
Many thanks for your time Gents, The antennas were intended for outdoor use and constant handling. being encased in hard plastic obviously enhances those functions. My experience has been at the other end of the spectrum so to speak and I (incorrectly) assumed an antenna picks up an electrical signal. Putting a layer of insulating plastic on it seemed contradictory. If antenna is detecting magnetic signals obviously a different story. When I mentioned impedance I mislead you. Wasnt referring to antenna impedance but the impedance looking back form the recieving antenna to the signal source ( thats what us old analogue designers do, Norton/Thevenin equivalent circuits etc !!!!) and the effect on that a layer of plastic has. Your combined efforts have answered a lot of my questions, thanks for your time. Unfortunately the clueless idiot from Poland has woken up and is making his outdated claims again... What you should know is (and apparently have realized by now) that the antenna impedance is not an impedance between its elements and the surrounding air, but a "radiation impedance" that results from the antenna emitting an electromagnetic field. This field traverses plastic, a vacuum, air etc without problem so it does not matter if you coat the elements. |
Hopefully not off topic-link
"John" wrote in message
. au... Its why you should never leave a powerpoint switched on. You end up with a heap of electrons on the floor. And a hole under the neutral hole. Not if you leave a plug in the socket. That'll stop the electrons. What about the neutrons, protons and croutons? Regards, Ian. |
Hopefully not off topic-link
Ian wrote:
"John" wrote in message . au... Its why you should never leave a powerpoint switched on. You end up with a heap of electrons on the floor. And a hole under the neutral hole. Not if you leave a plug in the socket. That'll stop the electrons. What about the neutrons, protons and croutons? Croutons are especially nasty when they end up on the floor... |
Hopefully not off topic-link
"Rob" wrote in message
... Ian wrote: "John" wrote in message . au... Its why you should never leave a powerpoint switched on. You end up with a heap of electrons on the floor. And a hole under the neutral hole. Not if you leave a plug in the socket. That'll stop the electrons. What about the neutrons, protons and croutons? Croutons are especially nasty when they end up on the floor... But you can weight them and they are easy to detect :-) |
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