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#71
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Peter O. Brackett wrote:
I beleive in working it all out from first principles, can't trust anybody else, except of course you and your wonderful programs. :-) Ever try to develop Morse code from first principles? :-) -- 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! =----- |
#72
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Dr. Slick wrote:
I've got the same paper. It's a bit confusing, because then he calls [s]**2 = [(ZL - Zo*) / (ZL + Zo)]**2 the "power reflection coefficent". Where if you take the square root to the power reflection coefficient, you should get the voltage r. c. So perhaps s = (ZL - Zo*) / (ZL + Zo) really IS the voltage R. C., even in this paper! There's no confusion at all (except here on this newsgroup). The power reflection coefficient is known as the "Reflectance" in optics. The voltage reflection coefficient that we know and love in RF is one of the Fresnel (1788-1827) Equations. In optics, it is known as the "amplitude reflection coefficient", equation 4.34 in _Optics_, 4th edition. May I suggest that everyone obtain a copy of _Optics_, by Hecht, and contribute to his/her basic understanding of EM waves. Light was detectable eons before RF and thus had an extreme head start. We are presently arguing principles that were already resolved by the end of the 18th century. -- 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! =----- |
#73
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![]() OHH MY GHOD!! Your sooo smart to find my real name! (slaps head in stupidity, i forgot about a Google search, Dammit!) ![]() Slick Ah, the fatuous irony of youth. Say, Yee, I'm curious. Did you ever attend Lowell? Also, what got you interested in radio? I would think a self-anointed artist cum musician like you would avoid technical subjects like the plague. You don't seem to be doing very well at any rate. 73, Tom Donaly, KA6RUH |
#74
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![]() Sorry Peter, quantum physics disagrees with you. It's the electrons, photons, and virtual photons that are real. :-) -- 73, Cecil http://www.qsl.net/w5dxp What's the radius of a virtual photon, Cecil? 73, Tom Donaly, KA6RUH |
#76
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"Peter O. Brackett" wrote in message link.net...
Slick: [snip] Correction: rho = (Z - conj(R))/(Z + (R)), the conjugate being only in the denominator. Slick [snip] Well here we have to part company. Not using the same "thing" in both numerator and denominator *is* being inconsistent! See my algebraic development in another posting on this thread. Opps Again! Correction: rho = (Z - conj(R))/(Z + (R)), the conjugate being only in the numerator. Slick |
#77
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Cecil:
[snip] Ever try to develop Morse code from first principles? :-) -- 73, Cecil http://www.qsl.net/w5dxp [snip] Even Morse didn't do that! Apparently historians believe that his faithful servant Vail did that. -- Peter K1PO dah di dah |
#78
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"David Robbins" wrote in message ...
"Dr. Slick" wrote in message om... [s]**2 = [(ZL - Zo*) / (ZL + Zo)]**2 the "power reflection coefficent". Note the squares. yes, please do note the squares.... and remember, just because [s]**2 = [(ZL - Zo*) / (ZL + Zo)]**2 does NOT mean that s = (ZL - Zo*) / (ZL + Zo) this is the one big trap that all you guys that like to use power in your calculations fall into. just because you know the power doesn't mean that you know squat about the voltage and current on the line. you can not work backwards. that is why it is always better to work with voltage or current waves and then in the end after you have solved all those waves you can always calculate power if you really need to know it. yes, but he does say that s = (ZL - Zo*) / (ZL + Zo) , first. But he foolishly calls it a "power wave R. C." Then he squares the magnitudes [s]**2 = [(ZL - Zo*) / (ZL + Zo)]**2 And calls this the "power R. C." The bottom label is fine, we've all see this before, as the ratio of the RMS incident and reflected voltages, when squared, should give you the ratio of the average incident and reflected powers, or the power R. C. But to call the voltage reflection coefficient a "power wave R. C." is really foolish, IMO. Slick |
#79
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![]() Design, development and test of circuit and board level RF designs including impedance matching networks (simulating on MIMP) for E-PHEMT power amplifiers for the GSM, DCS, and PCS cellular bands (880MHz-1900MHz). Simulations on ADS to assess manufacturability and robustness. Bias tuning for EDGE mode EVM and Adjacent channel power. Optimize circuit design and board layout for PAE, gain flatness, stability under mismatched loads, receive-band noise, AM to PM, input VSWR and harmonic suppression. Design and construction of FM stereo multiplexed Phase Locked Loop transmitters, broadband design (88-108MHz). Design and selection of VCOs, pre-scalers, and loop filters. Antenna design and construction: 5/8ths vertical groundplane, 1/4 wavelength, and dipoles. Compressor-limiter and Chebychev Low-pass filter design. Microwave (MMIC) testing and tuning (2-18GHz). Design of equalizers and filters. Linearity of Detector Logarithmic Video Amplifiers. Temperature compensation networks. You win a prize if you can guess where i last worked... Your turn Tom... Slick Very impressive. You've designed 5/8s vertical ground planes, 1/4 wavelength [something or others, I guess] and dipoles. Where are you working now? Did you go to Lowell? 73, Tom Donaly, KA6RUH |
#80
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Tdonaly wrote:
What's the radius of a virtual photon, Cecil? From _Optics_, by Hecht: "When two electrons repel one another, or an electron and proton attract, it is by emitting and absorbing virtual photons and thereby transferring momentum from one to the other, ... Virtual photons can never escape to be detected directly by some instrument." -- 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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