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#1
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Jim Kelley wrote:
Yes, Cecil. I have considered it, and I agree. It just bothers me when people forget what the minus sign means, and try using it to make unrealistic claims. At least for real Z0's, it should be consistent. Wouldn't a rho of 0.5 at 20 degrees would be the same as a rho of -0.5 at 200 degrees? -- 73, Cecil, W5DXP |
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#2
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On Fri, 26 Sep 2003 12:53:50 -0500, Cecil Moore
wrote: At least for real Z0's, it should be consistent. Wouldn't a rho of 0.5 at 20 degrees would be the same as a rho of -0.5 at 200 degrees? Hi Cecil, The Reflection Coefficient is a characteristic of the Load or Source, not a value projected all along the line. This is the teaching of Chipman that you undoubtedly speed-read past on your way to the cut-and-paste opportunities you sought. When are you going to ride your bike back to the library to fill all these shortfalls of his teachings you so liberally sprinkle your missives with? 73's Richard Clark, KB7QHC |
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#3
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Richard Clark wrote:
The Reflection Coefficient is a characteristic of the Load or Source, not a value projected all along the line. This is the teaching of Chipman that you undoubtedly speed-read past on your way to the cut-and-paste opportunities you sought. For lossless transmission lines, |rho| = Sqrt(Pref/Pfwd). You don't even need to know the load and/or source impedances. When are you going to ride your bike back to the library to fill all these shortfalls of his teachings you so liberally sprinkle your missives with? Just as soon as I am over my sinusitis and have a day off. -- 73, Cecil, W5DXP |
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#4
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On Fri, 26 Sep 2003 14:35:33 -0500, Cecil Moore
wrote: For lossless transmission lines, |rho| = Sqrt(Pref/Pfwd). You don't even need to know the load and/or source impedances. Hi Cecil, How did you get a -1 out of your |rho|? Take a box of kleenex on your bike ride to the library - your logic is dribbling. 73's Richard Clark, KB7QHC |
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#5
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Richard Clark wrote:
wrote: For lossless transmission lines, |rho| = Sqrt(Pref/Pfwd). You don't even need to know the load and/or source impedances. How did you get a -1 out of your |rho|? I probably should have said rho^2 = Pref/Pfwd. When Pref = Pfwd, rho can be plus or minus one. I used |rho| to indicate a magnitude, sans phase angle, not an absolute value. -- 73, Cecil http://www.qsl.net/w5dxp -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
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#6
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On Fri, 26 Sep 2003 23:15:44 -0500, Cecil Moore
wrote: Richard Clark wrote: wrote: For lossless transmission lines, |rho| = Sqrt(Pref/Pfwd). You don't even need to know the load and/or source impedances. How did you get a -1 out of your |rho|? I probably should have said rho^2 = Pref/Pfwd. When Pref = Pfwd, rho can be plus or minus one. I used |rho| to indicate a magnitude, sans phase angle, not an absolute value. Hi Cecil, You obviously don't respect/know the difference between a dependant variable (rho) and independent variables (P). Rho is a dependency of the interface, not a translatable value you are forcing illogic to perform. You really need to ride your bike to the library more and offer these poor examples less. Since Rho is the dependant variable, even squared (for you to force a -1 into this charade) requires a concurrent observance of a negative in the right hand side (negative power - perhaps if you were in a black hole). The long and short of it is that this confirms Jim's observance of your forced math serving your canards rather than logic. Oh, and please stop offering and polluting Chipman as a resource when you've only copied one page. 73's Richard Clark, KB7QHC |
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#7
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Richard Clark wrote:
Since Rho is the dependant variable, even squared (for you to force a -1 into this charade) requires a concurrent observance of a negative in the right hand side (negative power - perhaps if you were in a black hole). You seem to have forgotten some junior high math, Richard. There is no requirement for a negative anywhere in order for the square root of a number to be negative. The square root of 100W/100W has two values, plus or minus one, and sure enough, an open or a short will cause 100% reflection. BTW, I copied that page in Chipman with which you are having such a problem and I don't see the problem you described. Absolutely nothing said about reflections from the source. In fact, the source has the same impedance as the transmission line so there are no reflections from the source. -- 73, Cecil http://www.qsl.net/w5dxp -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
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#8
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Cecil Moore wrote in message ...
.... Wouldn't a rho of 0.5 at 20 degrees would be the same as a rho of -0.5 at 200 degrees? Yes, and any other complex quantity would likewise be the same expressed either way. But it would certainly be confusing to the readers. It would be much better to stick with rectangular or with polar and not mix them in the same quantity. Of course, sometimes one is easier to work with, or offers more insight, than the other and you're welcome to convert between them at any time. Let's see if we can keep it more along the lines of 0.5 at 20 degrees being (very nearly) the same as .4698+j.1710 Cheers, Tom |
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