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#2
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![]() Cecil Moore wrote: In your above pulse example, there is no interference at the impedance discontinuity and therefore a Z0-match doesn't even exist. A Z0-match depends upon a steady-state supply of RF waves. A Z0-match at the input of a tuner works exactly like the 1/4WL thin-film anti-reflected glass coating. If one sends a 1/2WL pulse of light at that piece of glass, there will be reflections. Anti-reflective glass depends upon a steady-state supply of light waves. One of the cancellation components is 180 degrees older than the other one. You really do need to choose your words a bit more carefully, Cecil. Let's return to the Signal Generators equipped with Circulators and Loads (SGCL). Would you agree that the feedline contains 300 joules in the following example? 200W SGCL----one second long lossless feedline----100W SGCL 200W-- --100W Yes. But how much is there with the circulator load removed? (Not replaced by an autotuner.) Numbers please. Why you suppose I keep asking this question, Cecil? 73, ac6xg |
#3
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Jim Kelley wrote:
You really do need to choose your words a bit more carefully, Cecil. Your statement is a personal opinion without technical content. 200W SGCL----one second long lossless feedline----100W SGCL 200W-- --100W Yes. But how much is there with the circulator load removed? (Not replaced by an autotuner.) Numbers please. OK, let's remove the circulator loads and replace them with unknown devices or objects inside black boxes. Here's the same one second long lossless feedline with unknown black boxes connected at each end (where BB stands for black box). BB#1------one second long lossless feedline------BB#2 200W-- --100W Given: all conditions on the one second long lossless feedline are identical in both of the above examples. The laws of physics tell us that the joules in the two lines with identical conditions are equal, i.e. 300 joules in these two cases. It doesn't matter what exists or doesn't exist at the two ends of the line. 200 watts forward and 100 watts reverse requires 300 joules/sec. In other words, given a purely resistive Z0 and a properly calibrated wattmeter, it is impossible to get 200 watts of forward power and 100 watts of reverse power without there being 300 joules in the one second long lossless line. If there wasn't 300 joules in that line, we wouldn't measure 200 watts forward and 100 watts reverse. -- 73, Cecil, http://www.qsl.net/w5dxp |
#4
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Jim Kelley wrote:
Why you suppose I keep asking this question, Cecil? Because you believe in intelligent waves that somehow sense their ultimate fate and therefore know how much energy to carry or not? Wave#1: "I am going to be dissipated in a circulator load and therefore, I must contain N joules of energy." Wave#2: "I am not going to be dissipated in a circulator load and therefore, I must contain zero energy." Given the following two configurations where BB stands for Black Box: BB#1----one second long lossless feedline----BB#2 200W-- --100W BB#3----one second long lossless feedline----BB#4 200W-- --100W Given: All voltages, currents, fields, and powers are identical in both systems. Please present us with a set of Black Boxes that will satisfy your assertions and result in different energy magnitudes in the two lines. -- 73, Cecil http://www.qsl.net/w5dxp |
#5
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![]() Cecil Moore wrote: Jim Kelley wrote: Why do you suppose I keep asking this question, Cecil? Because you believe in intelligent waves that somehow sense their ultimate fate and therefore know how much energy to carry or not? No. That's something you keep insisting on talking about. Try to keep your mind focussed on the fact that we're discussing the steady state. (Or as you might proffer, after the waves have "decided" what they're going to do.) How about we just get back to the question. Energy in your 1 sec. transmission line, only with no load on the circulator (and no autotuner). How much? Explain. Try it! 73 de ac6xg |
#6
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Jim Kelley wrote:
How about we just get back to the question. Energy in your 1 sec. transmission line, only with no load on the circulator (and no autotuner). How much? Explain. Try it! I honestly don't know what happens when the third port of the circulator is unterminated but it is irrelevant because the steady-state forward and reflected powers would not be the same. I concede to you the fact that one can always make an example too complicated to analyze presumably for the purpose of diverting the issue. But why would you want to divert the issue? The real question is: Do two identical feedlines with identical signal characteristics contain the same amount of energy as in the following two examples. Again SGCL is a Signal Generator with a Circulator and Load resistor. Z0 is 50 ohms and the load is 291.42 ohms. 200W SGCL-----one second long lossless feedline---load 200W-- --100W lossless 100W---tuner--one second long lossless feedline---load 200W-- --100W It is easy to prove that the first example contains 300 joules in the feedline after two seconds. It is easy to specify that the conditions in the feedline in the two examples are identical during steady-state. Are you asserting that two identical feedlines with identical conditions contain a different number of joules? I have another example in another posting. -- 73, Cecil http://www.qsl.net/w5dxp |
#7
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![]() Cecil Moore wrote: Jim Kelley wrote: How about we just get back to the question. Energy in your 1 sec. transmission line, only with no load on the circulator (and no autotuner). How much? Explain. Try it! I honestly don't know what happens when the third port of the circulator is unterminated You should think about it because amateur radios don't usually have circulators on their output, and the result illuminates a corner of the discussion that you've been pretty closed minded about. Without a load on the circulator, you must know that no energy can be flowing to it or through it. No power is being dissipated by it. What effect should that have on the total energy in the transmission line, and why? I hope it's not true about Reg. That would be a huge loss. Perhaps somebody will archive his website. 73, ac6xg |
#8
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On Wed, 30 Aug 2006 10:17:44 -0700, Jim Kelley
wrote: I hope it's not true about Reg. That would be a huge loss. Perhaps somebody will archive his website. Hi Jim, The announcement came from his account, and his computer. I've archived his site, but for others who wish to do the same, the best tool for that purpose can be found at: http://www.httrack.com This is a website harvesting robot that will replicate an entire website into the directory of your choice (changing links so that you can browse it on your system). 73's Richard Clark, KB7QHC |
#9
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Jim Kelley wrote:
Cecil Moore wrote: I honestly don't know what happens when the third port of the circulator is unterminated You should think about it because amateur radios don't usually have circulators on their output, and the result illuminates a corner of the discussion that you've been pretty closed minded about. I know what happens if the circulator is not present. I just don't don't know what happens with an unterminated circulator. Maybe you can help me out here. If the load resistors are removed from the circulators in the previous experiment, what is the forward power and reflected power readings on the one second long lossless transmission line during steady-state? Without a load on the circulator, you must know that no energy can be flowing to it or through it. No power is being dissipated by it. What effect should that have on the total energy in the transmission line, and why? Let's remove the circulators and try to figure out what happens. Let's assume the signal generator is a Thevenin equivalent with an internal resistance of 50 ohms and not equipped with a circulator. 200W SG---one second long 50 ohm lossless feedline---100W SG Would you agree with me that during the first second, the feedline is loaded with 300 joules because there have been no reflections? What happens after that depends upon the reflection coefficients at the signal generators. But the $64k question is what happens to the original 300 joules? I hope it's not true about Reg. That would be a huge loss. Perhaps somebody will archive his website. One of the posters to the news of Reg's death was whom I suspect is Reg's son (or nephew). Humans are mortal and can die at any time. My son died when he was 8 months old. I wish he had lived as long as Reg who certainly had a full, useful, and colorful life. -- 73, Cecil http://www.qsl.net/w5dxp |
#10
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Jim Kelley wrote:
You should think about it because amateur radios don't usually have circulators on their output, and the result illuminates a corner of the discussion that you've been pretty closed minded about. Here's a brainteaser for you, Jim. Assume the following example under steady-state conditions: XMTR--X--tuner--Y--one second long lossless feedline---291.42 ohms Ps=100W Pfor=200W-- --100W=Pref PL=100W The lossless tuner is tuned for a Z0-match so there is zero reflected power at point 'X'. The Z0 of the feedline is 50 ohms. The voltage reflection coefficient at the load is 0.707 making the power reflection coefficient 0.5 We suddenly disconnect the source at point 'Y'. After the source is disconnected, how many joules of energy are delivered to the load? _____ How many seconds does it take to dissipate all the energy in the feedline? _____ On a second by second basis, how much power is delivered to the load after the disconnect? _____ _____ _____ _____ _____ -- 73, Cecil, http://www.qsl.net/w5dxp |
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