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#1
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On 5/19/2011 7:03 AM, Cecil Moore wrote:
On May 18, 6:13 pm, John wrote: So, you're saying that the Smith chart is wrong? The Smith Chart is a tool - a blank graph. How could it be wrong? Like any tool, it has limitations and can be abused. In that case I have no need of S11 or reflections or light. I only need to know that the Smith chart tells me that a 200 ohm load looks like a 50 ohm load through a 1/4WL-100 ohm line. I made it as simple as possible but no simpler. John |
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#2
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On May 19, 12:53*pm, John KD5YI wrote:
In that case I have no need of S11 or reflections or light. I only need to know that the Smith chart tells me that a 200 ohm load looks like a 50 ohm load through a 1/4WL-100 ohm line. Well there you go - my point exactly - it "looks like" but appearances can be deceiving. You and I know that they are not identical because we are smarter than the average bear and the IEEE has different definitions for those two radically different kinds of impedances. We know that it is a virtual image of 50 ohms because no 50 ohm resistor exists in reality and no zero reflection coefficient exists in reality. In mathematical terms, there is no one to one correspondence between a 50 ohm dummy load and a 50 ohm antenna. -- 73, Cecil, w5dxp.com |
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#3
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On 5/19/2011 1:53 PM, Cecil Moore wrote:
On May 19, 12:53 pm, John wrote: In that case I have no need of S11 or reflections or light. I only need to know that the Smith chart tells me that a 200 ohm load looks like a 50 ohm load through a 1/4WL-100 ohm line. Well there you go - my point exactly - it "looks like" but appearances can be deceiving. You and I know that they are not identical because we are smarter than the average bear and the IEEE has different definitions for those two radically different kinds of impedances. We know that it is a virtual image of 50 ohms because no 50 ohm resistor exists in reality and no zero reflection coefficient exists in reality. In mathematical terms, there is no one to one correspondence between a 50 ohm dummy load and a 50 ohm antenna. -- 73, Cecil, w5dxp.com Well, Cecil, we've now reached the end. No resistor exists in reality so no transmitters, waves, light, transmission lines exists in reality. There is no one to one correspondence between you and sanity. This is just plain stupid. You only want to argue. John |
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#4
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On May 19, 3:21*pm, John KD5YI wrote:
This is just plain stupid. I agree. Your above posting is just plain stupid. You are stating the opposite of what I have said hoping some readers will not notice. Resistors exist *in reality* e.g. in dummy loads. You are promoting E/ I ratios, existing as virtual resistances, to be as real as a physical resistor. Hopefully, no one ever loads his virtual gun with one of those virtual resistances and fires it at you. Question is, would you die or not? It has been said that everyone creates his own reality and it must be true. You guys have created models of reality in your minds that bear very little resemblance to the real world. In the field of optics, an real image that actually exists in reality is clearly differentiated from a virtual image which is an illusion that doesn't actually exist where it appears to exist. Light waves are EM waves. RF waves are EM waves. You guys are promoting a model that considers virtual images to actually exist at the point where they appear to exist but are only an illusion. I agree with you - that is just plain stupid. To summarize: Resistors, capacitors, and inductors, defined under the concept of impedors (from "The IEEE Dictionary") are real-world devices with a physical existence - one can pick them up and touch them. E/I ratios, containing resistance plus capacitive or inductive reactance, are impedances that do not have a physical existence. Their existence is conceptual and exists only in human minds capable of concepts (much like the concept of God). When you are standing four feet from a mirror and your image appears four feet behind the mirror, you are arguing that you can replace your actual self with an alternate self four feet behind the mirror and everything will be exactly the same. I agree with you - that is just plain stupid. -- 73, Cecil, w5dxp.com |
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#5
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On 19 mayo, 23:15, Cecil Moore wrote:
On May 19, 3:21*pm, John KD5YI wrote: This is just plain stupid. I agree. Your above posting is just plain stupid. You are stating the opposite of what I have said hoping some readers will not notice. Resistors exist *in reality* e.g. in dummy loads. You are promoting E/ I ratios, existing as virtual resistances, to be as real as a physical resistor. Hopefully, no one ever loads his virtual gun with one of those virtual resistances and fires it at you. Question is, would you die or not? It has been said that everyone creates his own reality and it must be true. You guys have created models of reality in your minds that bear very little resemblance to the real world. In the field of optics, an real image that actually exists in reality is clearly differentiated from a virtual image which is an illusion that doesn't actually exist where it appears to exist. Light waves are EM waves. RF waves are EM waves. You guys are promoting a model that considers virtual images to actually exist at the point where they appear to exist but are only an illusion. I agree with you - that is just plain stupid. To summarize: Resistors, capacitors, and inductors, defined under the concept of impedors (from "The IEEE Dictionary") are real-world devices with a physical existence - one can pick them up and touch them. E/I ratios, containing resistance plus capacitive or inductive reactance, are impedances that do not have a physical existence. Their existence is conceptual and exists only in human minds capable of concepts (much like the concept of God). When you are standing four feet from a mirror and your image appears four feet behind the mirror, you are arguing that you can replace your actual self with an alternate self four feet behind the mirror and everything will be exactly the same. I agree with you - that is just plain stupid. -- 73, Cecil, w5dxp.com Cecil, I already expected that you wouldn't solve my brainteaser (so I did it in advance), Here is the result for the 100V, 4 MHz sinusoidal source in series with 796pF, load pulling with 51.2 Ohms and 44.6 Ohms: V_out (51.2 Ohms) = 71.5V, I_out = 1.396A V_out (44.6 Ohms) = 66.5V, I_out = 1.491A Delta_V = 5.0V, Delta_I = 0.095A, Hence Rout = 52.6 Ohms. Power into 50 Ohms = 50W. ¡Really strange!, that a fully imaginary output impedance of -j50 Ohms results in real 52.6 Ohms output impedance based on the scalar load pulling referenced by you. I also applied complex load pulling (that is taking phase change into account) and Tom's off-carrier injection method to the same source. Both methods put out Zout = -j50 Ohms (yes, the correct value). You are criticizing Tom's method without any solid foundation, but you referenced to a method with very limited application as shown in this simple example. You are mixing coherent signal theory with non-coherent signal theory (narrow band RF versus unspecified optical), also your reply above has no relevance to PA's for HF amateur service. Cecil, we have all our specialities and limitations. It is becoming clear that you lack experience in the field of signal processing and RF (systems) Engineering. This is no problem, because many people can live without it. Instead of continuing the way you do, you can better try to grab some of the concepts offered by others. I am sure it will give you better insight in what happens in RF systems, in considerably less time. Wim PA3DJS www.tetech.nl |
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