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#1
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The complete text referenced here can be accessed at:
http://eznec.com/misc/food_for_thought/ The first one is "Forward and reverse power" and is much easier to read if it is copied-and-pasted into Word. The first comment is just a nit: "(the current isn't transformed by the half wavelength line either.)" A 1/2 wavelength of transmission line reverses the phase of the current, certainly a 180 degree "transformation". The main point centers around this false statement: "While the nature of the voltage and current waves when encountering an impedance discontinuity is well understood, we're lacking a model of what happens to this "reverse power" we've calculated." Absolutely false! We are not lacking a model. We have time- tested models that people with closed minds simply refuse to consider. One such model is the s-parameter analysis presented in HP's App Note 95-1, available on the web. Quoting: "Another advantage of s-parameters springs from the simple relationship between the variables a1, a2, b1, and b2, and various *POWER WAVES*. ... s-parameters are simply related to power gain and mismatch loss, quantities which are often of more interest than the corresponding voltage functions." (emphasis mine) The model is there. Concrete brains refuse to take a look and instead call it "gobbledegook" (sic). There's another model that agrees 100% with an s-parameter analysis and it is from the field of optics, covered in detail in _Optics_, by Hecht. Non-glare glass works the same way as a 1/4WL matching section in a transmission line. Again the model is there, just ignored by gurus on this newsgroup which leads to demonstrably wrong conclusions on their parts. What happens to the energy in EM light waves has been known and understood for many decades and cannot be understood without an understanding of the laws of physics governing interference between EM waves. Likewise, what happens to the energy in EM RF waves cannot be understood without an understanding of those same laws of physics. There are many posters to r.r.a.a who have no clue about the laws of physics governing interference between EM waves. That ignorance is the entire problem with this discussion. Solution: Alleviate the ignorance. Quoting again from Roy's web page: 'ANY MODEL PRESENTED TO ACCOUNT FOR WHAT HAPPENS TO "FORWARD" AND "REVERSE" POWER AT TRANSMISSION LINE ENDS HAD BETTER GIVE RESULTS THAT AGREE WITH THE ABOVE TABLE.' And, of course, the two above power/energy models agree exactly with Roy's table but that doesn't seem to matter one iota. They are still "gobbledegook" (still sic). -- 73, Cecil, http://www.qsl.net/w5dxp ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
#2
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On Thu, 30 Jun 2005 11:05:57 -0500, Cecil Moore
wrote: Non-glare glass works the same way as a 1/4WL matching section in a transmission line. One trivial example that you thoroughly bumbled through every mistake possible, arriving at no answer before abandoning. |
#3
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Richard Clark wrote:
Cecil Moore wrote: Non-glare glass works the same way as a 1/4WL matching section in a transmission line. One trivial example that you thoroughly bumbled through every mistake possible, arriving at no answer before abandoning. It was an example for Jim Kelley to respond to. He declined to discuss it, nobody else (including you) responded with any technical content, so the thread was abandoned. If you have anything technical to contribute, feel free to fire it up again. That happens a lot on this newsgroup. When someone realizes that he is about to be proven wrong in public, he simply goes away - human nature. -- 73, Cecil, http://www.qsl.net/w5dxp ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
#4
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Cecil Moore wrote:
Richard Clark wrote: Cecil Moore wrote: Non-glare glass works the same way as a 1/4WL matching section in a transmission line. One trivial example that you thoroughly bumbled through every mistake possible, arriving at no answer before abandoning. It was an example for Jim Kelley to respond to. He declined to discuss it, nobody else (including you) responded with any technical content, so the thread was abandoned. If you have anything technical to contribute, feel free to fire it up again. That happens a lot on this newsgroup. When someone realizes that he is about to be proven wrong in public, he simply goes away - human nature. Cecil, you never actually prove anyone wrong, you just get excited and irrational whenever anyone disagrees with you. You're confusing the fear of being proven wrong with just giving up in disgust at your silly antics. 73, Tom Donaly, KA6RUH |
#5
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Tom Donaly wrote:
You're confusing the fear of being proven wrong with just giving up in disgust at your silly antics. More of the same personal stuff. How about some technical content for a change? -- 73, Cecil, http://www.qsl.net/w5dxp ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
#6
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On Thu, 30 Jun 2005 12:14:36 -0500, Cecil Moore
wrote: More of the same personal stuff. How about some technical content for a change? http://www.qsl.net/w5dxp/weblaser.GIF (which I am sure you will soon hustle off in embarrassment) For an angle of incidence of 30° How much power is reflected from Surface A (first incidence)? How much power is reflected from Surface B (first incidence)? How much power is transmitted through all interfaces? :-) |
#7
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On Thu, 30 Jun 2005 11:43:24 -0500, Cecil Moore
wrote: That happens a lot on this newsgroup. When someone realizes that he is about to be proven wrong in public, he simply goes away - human nature. No doubt this is a set up for abandoning my other question in this thread Message-ID: |
#8
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Richard Clark wrote:
On Thu, 30 Jun 2005 12:14:36 -0500, Cecil Moore wrote: More of the same personal stuff. How about some technical content for a change? http://www.qsl.net/w5dxp/weblaser.GIF (which I am sure you will soon hustle off in embarrassment) For an angle of incidence of 30° The angle of incidence is always 90 degrees. It is drawn that way because it cannot be drawn in one dimension. This is typical of physics textbook drawings. An angle of incidence of 30 degrees is irrelevant to this particular example. How much power is reflected from Surface A (first incidence)? The reflectance is 0.01, so 1%. First incidence 0.01 watts How much power is reflected from Surface B (first incidence)? The reflectance is 0.01, so 1%. First incidence is 0.0099 watts Steady-state after re-reflection is 0.01010101 watts How much power is transmitted through all interfaces? One watt net to the "load". The steady-state forward power in the thin film is 1.010101 watts of which 0.010101 is a steady-state internal reflection from surface B. -- 73, Cecil, http://www.qsl.net/w5dxp ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
#9
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On Thu, 30 Jun 2005 13:43:13 -0500, Cecil Moore
wrote: An angle of incidence of 30 degrees is irrelevant to this particular example. Changing the question to suit the answer, Hmm? As if it mattered! How much power is reflected from Surface A (first incidence)? The reflectance is 0.01, so 1%. First incidence 0.01 watts depending upon the polarization r¬ = 1.583% and r|| = 0.5485% Splitting the difference (1.066%) 0.0107W or 0.9893W @ 24° available at the next interface How much power is reflected from Surface B (first incidence)? The reflectance is 0.01, so 1%. First incidence is 0.0099 watts depending upon the polarization r¬ = 1.3381% and r|| = 0.7099% Splitting the difference (1.024%) 0.0101W or 0.9792W @ 19° available at the next interface How much power is transmitted through all interfaces? One watt net to the "load". Already provided as 0.9792W ********************************** Since you couldn't answer the original question, let's explore how accurate your answer to your own question was: How much power is reflected from Surface A (first incidence)? The reflectance is 0.01, so 1%. First incidence 0.01 watts depending upon the polarization r¬ = 0.9999% and r|| = 0.9999% Splitting the difference (0.9999%) 0.0100W or 0.9900W @ 0° available at the next interface How much power is reflected from Surface B (first incidence)? The reflectance is 0.01, so 1%. First incidence is 0.0099 watts depending upon the polarization r¬ = 0.9998% and r|| = 0.9998% Splitting the difference (0.9998%) 0.0099W or 0.9801W @ 0° available at the next interface How much power is transmitted through all interfaces? One watt net to the "load". Already provided as 0.9801W But, hey, what's 2% error in a conservation of energy equation? You can prove anything (especially your absolute proofs) if you simply discard precision. Pons and Fleishman proved cold fusion by throwing away fewer digits than you. Well, for 1W of light and presuming cancellation (you cannot achieve full cancellation); this leaves 100µW of light reflected from a non-reflecting layer - which is quite bright. So, energy is conserved, and there is no such thing as complete cancellation. By the way, the math is available from: Hecht, Eugene, Optics, 2nd Ed, Addison Wesley, 1987 or perhaps you should invest in: Hecht, Eugene, Optics, Schaum's Outline Series, McGraw-Hill ,1975 |
#10
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Richard Clark wrote:
But, hey, what's 2% error in a conservation of energy equation? The error is yours. During steady-state, the forward power in the thin film is 1.0101 watts. 1% of that is 0.0101 watts. 1.0101 - 0.0101 = one watt delivered to the "load". 100% accuracy is guaranteed because it is a mental conceptual exercise. To summarize: Forward power in air is one watt. Reflected power in air is zero watts. Forward power in the thin-film is 1.010101010101010101 watts. Reflected power in the thin-film is 0.10101010101010101 watts. Power delivered through Surface B is exactly one watt, exactly the output of the laser. Exactly the difference between the steady-state forward and reflected power in the thin-film. Well, for 1W of light and presuming cancellation (you cannot achieve full cancellation) That's the great thing about a mental conceptual example. Full cancellation is guaranteed. So, energy is conserved, and there is no such thing as complete cancellation. True for real world stuff. False for mental conceptual examples like the one being discussed. -- 73, Cecil, http://www.qsl.net/w5dxp ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 100,000 Newsgroups ---= East/West-Coast Server Farms - Total Privacy via Encryption =--- |
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