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#1
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Smith Charts do not have anything to do with antenna efficiency or resonance. The only thing that Smith Charts does is explain what is happening inside of a piece of coax X inches long. Note I do not use feet - since that is too vague.
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#2
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Relationship Between Antenna Efficiency and Received Signal Strength
On 1/23/2014 3:30 PM, Channel Jumper wrote:
Jerry Stuckle;814478 Wrote: On 1/22/2014 5:32 PM, Irv Finkleman wrote:- Q. Is there a relationship between the efficiency of an antenna and the received signal strength? - That depends on a lot of factors such as number of radials, length, height above ground and ground conductivity, for start. Each situation is different. But generally, for antennas such as 1/4 wave verticals, radials will help. Unfortunately, the only way to predict how an antenna is going to work in a specific situation with any accuracy is with math and Smith Charts. So you can use the "tried and true" method - put it up and see what happens ================== I'm sorry Jerry, but you don't know what you are talking about. Smith Charts do not have anything to do with antenna efficiency or resonance. The only thing that Smith Charts does is explain what is happening inside of a piece of coax X inches long. Note I do not use feet - since that is too vague. Again, wrong. Smith Charts explain a LOT about antennas. But then I can see you've never used one - but you have to try to correct someone who knows more than you, anyway. But you only show your ignorance. And BTW - I was using Smith Charts before you were born. -- ================== Remove the "x" from my email address Jerry, AI0K ================== |
#3
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Relationship Between Antenna Efficiency and Received Signal Strength
On 1/24/2014 2:38 AM, Jeff wrote:
I'm sorry Jerry, but you don't know what you are talking about. Smith Charts do not have anything to do with antenna efficiency or resonance. The only thing that Smith Charts does is explain what is happening inside of a piece of coax X inches long. Note I do not use feet - since that is too vague. Whilst I agree with your first point, Smiths Charts do not "explain what is happening inside of a piece of coax X inches long". They are an easy way to plot impedances, and show what happens if you *change* the length of coax, but more importantly they give you an easy way of working out how to match impedances (with or without any length of coax involved). They can also display other valuable quantities such as Q. jeff They do if you know how to use them properly. For instance, they will tell you when the reactive portion of the impedance is zero (neither capacitive nor inductive), which indicates resonance. They will also tell you the antenna's impedance at a specific frequency. Both can be used to indirectly determine antenna efficiency. -- ================== Remove the "x" from my email address Jerry Stuckle ================== |
#4
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Relationship Between Antenna Efficiency and Received Signal Strength
On 1/25/2014 6:18 AM, Jeff wrote:
Whilst I agree with your first point, Smiths Charts do not "explain what is happening inside of a piece of coax X inches long". They are an easy way to plot impedances, and show what happens if you *change* the length of coax, but more importantly they give you an easy way of working out how to match impedances (with or without any length of coax involved). They can also display other valuable quantities such as Q. jeff They do if you know how to use them properly. For instance, they will tell you when the reactive portion of the impedance is zero (neither capacitive nor inductive), which indicates resonance. They will also tell you the antenna's impedance at a specific frequency. Both can be used to indirectly determine antenna efficiency. Rubbish, they tell you nothing more than the impedance at the point that you wish to plot it. They tell you nothing about how well an antenna may, or may, not radiate. A 50 ohm resistor will be purely resistive (parasitic elements neglected) but won't radiate well. Also an antenna does not have to resonant to radiate well or have high efficiency. Jeff Keep thinking that, Jeff, while those who know how to use Smith Charts continue to design antennas. Your ignorance is underwhelming. -- ================== Remove the "x" from my email address Jerry, AI0K ================== |
#5
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Relationship Between Antenna Efficiency and Received Signal Strength
On 1/26/2014 5:09 AM, Jeff wrote:
Rubbish, they tell you nothing more than the impedance at the point that you wish to plot it. They tell you nothing about how well an antenna may, or may, not radiate. A 50 ohm resistor will be purely resistive (parasitic elements neglected) but won't radiate well. Also an antenna does not have to resonant to radiate well or have high efficiency. Jeff Keep thinking that, Jeff, while those who know how to use Smith Charts continue to design antennas. Your ignorance is underwhelming. Well Jerry, please help me increase my knowledge. Please tell me now to show what "goes on *inside* a bit of coax" on a Smith chart, or how to show the efficiency of an antenna from a Smith chart. Jeff I'll tell you what, troll. You go to college. Get a EE degree. Learn the math and the theory. Them maybe you can understand basics and we can discuss the subject intelligently (although I doubt it). Usenet is not the place to try to teach you four years of math, physics and electronics. -- ================== Remove the "x" from my email address Jerry Stuckle ================== |
#6
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Relationship Between Antenna Efficiency and Received Signal Strength
On 1/26/2014 11:12 AM, Jeff wrote:
On 26/01/2014 15:50, Jerry Stuckle wrote: On 1/26/2014 5:09 AM, Jeff wrote: Rubbish, they tell you nothing more than the impedance at the point that you wish to plot it. They tell you nothing about how well an antenna may, or may, not radiate. A 50 ohm resistor will be purely resistive (parasitic elements neglected) but won't radiate well. Also an antenna does not have to resonant to radiate well or have high efficiency. Jeff Keep thinking that, Jeff, while those who know how to use Smith Charts continue to design antennas. Your ignorance is underwhelming. Well Jerry, please help me increase my knowledge. Please tell me now to show what "goes on *inside* a bit of coax" on a Smith chart, or how to show the efficiency of an antenna from a Smith chart. Jeff I'll tell you what, troll. You go to college. Get a EE degree. Learn the math and the theory. Them maybe you can understand basics and we can discuss the subject intelligently (although I doubt it). Been there done that, and spend 30+ designing and specifying radio equipment, and using Smith charts. Yea, right. I'll take it as a "no I can't" then. Which of course is true you can't how what "goes on *inside* a bit of coax" on a Smith chart, or how to show the efficiency of an antenna from a Smith chart. Nope, I'm not even going to try to teach the pig to sing, especially in a newsgroup. But trolls don't understand that. Try reading Mr Smith's excellent book on his Smith Chart and you might find out what it can and can't do!!! Jeff Try getting your EE degree along with the math, physics and electrical theory. Then maybe we can discuss this intelligently. -- ================== Remove the "x" from my email address Jerry Stuckle ================== |
#7
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Relationship Between Antenna Efficiency and Received Signal Strength
On 1/27/2014 2:40 AM, Jeff wrote:
Jeff Try getting your EE degree along with the math, physics and electrical theory. Then maybe we can discuss this intelligently. I am offering to discuss this intelligently by asking you to explain and enlighten me as to how a Smith chart shows what "goes on inside a bit of coax" on a Smith chart, or how to show the efficiency of an antenna from a Smith chart, but you are the one coming back with (incorrect) personal insults!! Jeff When you get the sufficient background in electronics, math and physics, we can discuss this intelligently. Until then, it's like teaching a pig to sing. -- ================== Remove the "x" from my email address Jerry Stuckle ================== |
#8
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Relationship Between Antenna Efficiency and Received Signal Strength
On 1/27/2014 12:31 PM, Jeff wrote:
On 27/01/2014 13:37, Jerry Stuckle wrote: On 1/27/2014 2:40 AM, Jeff wrote: Jeff Try getting your EE degree along with the math, physics and electrical theory. Then maybe we can discuss this intelligently. I am offering to discuss this intelligently by asking you to explain and enlighten me as to how a Smith chart shows what "goes on inside a bit of coax" on a Smith chart, or how to show the efficiency of an antenna from a Smith chart, but you are the one coming back with (incorrect) personal insults!! Jeff When you get the sufficient background in electronics, math and physics, we can discuss this intelligently. Until then, it's like teaching a pig to sing. You really are a very rude person. Jeff Oh, because I won't give you a the equivalent of a four-year degree for free on usenet? You really are a troll. -- ================== Remove the "x" from my email address Jerry, AI0K ================== |
#9
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Relationship Between Antenna Efficiency and Received Signal Strength
Jeff wrote:
I'm sorry Jerry, but you don't know what you are talking about. Smith Charts do not have anything to do with antenna efficiency or resonance. The only thing that Smith Charts does is explain what is happening inside of a piece of coax X inches long. Note I do not use feet - since that is too vague. Whilst I agree with your first point, Smiths Charts do not "explain what is happening inside of a piece of coax X inches long". They are an easy way to plot impedances, and show what happens if you *change* the length of coax, but more importantly they give you an easy way of working out how to match impedances (with or without any length of coax involved). They can also display other valuable quantities such as Q. jeff A Smith chart is a plot of reactance and resistance versus frequency and can be used for just about anything, if you know how to use one. In the case of an antenna, the chart shows what you have to match at any particular frequency and the resonant frequency of the antenna, i.e. the point where the reactance is zero. -- Jim Pennino |
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