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#21
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Richard Clark wrote:
Everything you write about light is pretty funny; your sheer lack of experience is revealed where you can't name what frequency glare is. Care to hazard a guess? In the light experiments I have been talking about, the glare is the same frequency as the laser beam, somewhere around 3x10^6 angstroms. -- 73, Cecil, 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! =----- |
#22
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On Tue, 06 Apr 2004 17:58:25 -0500, Cecil Moore
wrote: Richard Clark wrote: Everything you write about light is pretty funny; your sheer lack of experience is revealed where you can't name what frequency glare is. Care to hazard a guess? In the light experiments I have been talking about, the glare is the same frequency as the laser beam, somewhere around 3x10^6 angstroms. Quite Droll, I must admit. 3 MILLION Angstroms Hmmm? This is not a unit of frequency by the way, so I suppose some elementary instruction is in order. Let's see, ten billion angstroms equal 1 meter. If we do a simple conversion we find that your laser light operates at a wavelength of 0.3 millimeters (thicker than a hair). That would seem to be more suitable for Masers, not Lasers, and hardly light any way that you -ahem- look at it. Let's not even suppose it is a slip of the decimal (because it ain't). Calling it glare is icing on the cake. :-) So, you wanna try for what's behind door number three? Only one more round, because humor has a limited shelf life. Given both frequency and wavelength are stumpers, how about something more remedial: "What is the color of glare?" |
#23
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Richard Clark wrote:
SNIP Quite Droll, I must admit. 3 MILLION Angstroms Hmmm? This is not a unit of frequency by the way, so I suppose some elementary instruction is in order. SNIP Why isn't an Angstrom a measure of wavelength?? You yourself simply translated it into a parameter of your choice as 0.3 mm. My 4.0 MHz antenna is 120 feet. Is the unit of feet not a measure of wavelength? Could I not use a furlong as a unit of length? I offer that ANY unit of length is acceptable in expressing wavelength. DD |
#24
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![]() "Dave Shrader" wrote in message news:eURcc.82679$gA5.1031413@attbi_s03... Richard Clark wrote: SNIP Quite Droll, I must admit. 3 MILLION Angstroms Hmmm? This is not a unit of frequency by the way, so I suppose some elementary instruction is in order. SNIP Why isn't an Angstrom a measure of wavelength?? You yourself simply translated it into a parameter of your choice as 0.3 mm. My 4.0 MHz antenna is 120 feet. Is the unit of feet not a measure of wavelength? Could I not use a furlong as a unit of length? I offer that ANY unit of length is acceptable in expressing wavelength. DD he said frequency - not wavelength |
#25
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Richard Clark wrote:
On Tue, 06 Apr 2004 17:58:25 -0500, Cecil Moore wrote: Richard Clark wrote: Everything you write about light is pretty funny; your sheer lack of experience is revealed where you can't name what frequency glare is. Care to hazard a guess? In the light experiments I have been talking about, the glare is the same frequency as the laser beam, somewhere around 3x10^6 angstroms. Quite Droll, I must admit. 3 MILLION Angstroms Hmmm? This is not a unit of frequency by the way, so I suppose some elementary instruction is in order. Let's see, ten billion angstroms equal 1 meter. If we do a simple conversion we find that your laser light operates at a wavelength of 0.3 millimeters (thicker than a hair). That would seem to be more suitable for Masers, not Lasers, and hardly light any way that you -ahem- look at it. Let's not even suppose it is a slip of the decimal (because it ain't). Calling it glare is icing on the cake. :-) So, you wanna try for what's behind door number three? Only one more round, because humor has a limited shelf life. Given both frequency and wavelength are stumpers, how about something more remedial: "What is the color of glare?" -----= 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! =----- |
#26
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Richard Clark wrote:
Let's see, ten billion angstroms equal 1 meter. If we do a simple conversion we find that your laser light operates at a wavelength of 0.3 millimeters (thicker than a hair). Yep, I misread the units from a chart in Reference Data for Radio Engineers. I accidentally picked a point in the low infrared region. Macular Degeneration is playing havoc with my eyesight. But, FYI, infrared lasers are readily available. And EM is still EM no matter what the frequency. If it will make you happy, let's discuss the familiar helium-neon laser whose wavelength is 632.8 nm. Incidentally, you said anstroms are not a measure of frequency. FYI, neither is wavelength, your preferred units. :-) It really doesn't matter what EM frequency we discuss. We can cause reflections (glare) at any frequency. But the experiment I previously discussed used a coherent laser light source normal to the plane of the thin-film. The two problems solved in the following diagrams are virtually identical (where 'n' is the index of refraction). 100w laser-----air------|----1/4WL thin-film----|--flat black n=1.0 n=1.225 n=1.5 100w XMTR--50 ohm coax--|--1/4WL 61.2 ohm coax--|--75 ohm load The physical reflection coefficient magnitude is the same in both cases, ~0.1. If one understands how the thin-film eliminates reflections (glare) then one understands how the match point eliminates reflections an RF transmission line. How the thin-film works is explained at: http://www.mellesgriot.com/products/optics/oc_2_1.htm Incidentally, J. C. Slater, author of _Microwave_Transmission_, understood all this stuff way back in 1942. Here's a couple of quotes: "Thus a light wave incident on a discontinuity between two media, as a surface of separation of air and glass, is reflected. If the surfaces are separated by a quarter wave film of material whose index of refraction is the geometric mean of the indexes of the two media, however, the reflection can be eliminated;" And for RF transmission lines: "We can get a better understanding of this device by considering reflections at discontinuities. This method is useful in considering any impedance-matching device, and we shall think of it first in connection with the ordinary quarter wave transformer. The object of this transformer is to eliminate the reflection that would be present if the impedance Z1 were connected directly to Zt. The method of eliminating reflections is based on the INTERFERENCE between waves. Two waves half a wavelength apart are in opposite phases, and the sum of them, if their amplitudes are numerically equal, is zero. The fundamental principle behind the elimination of reflections is then to have each reflected wave CANCELED by another wave of equal amplitude and opposite phase. In order that this second wave may have traveled half a wavelength farther than the first, it is OBVIOUS that it must have gone a quarter wavelength farther up the line, and correspondingly a quarter of a wavelength back, before it meets the original reflected wave. In other words, two discontinuities in characteristic impedance, of such magnitude as to give equal amplitudes of reflected waves and spaced a quarter of a wavelength apart, will give no NET reflection and hence will not introduce reflections into the line." Mr. Slater goes on to provide an example like mine above. So my question is: If all this stuff was known and published as far back as 1942, why do you, Richard, reject it in 2004, 62 years later? -- 73, Cecil, 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! =----- |
#27
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Dave Shrader wrote:
Richard Clark wrote: SNIP Quite Droll, I must admit. 3 MILLION Angstroms Hmmm? This is not a unit of frequency by the way, so I suppose some elementary instruction is in order. SNIP Why isn't an Angstrom a measure of wavelength?? You yourself simply translated it into a parameter of your choice as 0.3 mm. It's even worse than that, Dave. Richard said Angstroms are not a measure of *FREQUENCY* and then turned around and used wavelength which is also NOT a measure of frequency. One wonders why his non-frequency units are superior to mine. :-) -- 73, Cecil, 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! =----- |
#28
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Roger Conroy wrote:
"Dave Shrader" wrote: Richard Clark wrote: Quite Droll, I must admit. 3 MILLION Angstroms Hmmm? This is not a unit of frequency by the way, so I suppose some elementary instruction is in order. Why isn't an Angstrom a measure of wavelength?? You yourself simply translated it into a parameter of your choice as 0.3 mm. I offer that ANY unit of length is acceptable in expressing wavelength. he said frequency - not wavelength He said frequency and then turned around and used wavelength. Wavelength is also NOT a unit of frequency. His "elementary instruction" violated his own objection and was thus inconsistent. -- 73, Cecil, 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! =----- |
#29
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On Wed, 07 Apr 2004 11:48:26 GMT, Dave Shrader
wrote: Richard Clark wrote: SNIP Quite Droll, I must admit. 3 MILLION Angstroms Hmmm? This is not a unit of frequency by the way, so I suppose some elementary instruction is in order. SNIP Why isn't an Angstrom a measure of wavelength?? You yourself simply translated it into a parameter of your choice as 0.3 mm. My 4.0 MHz antenna is 120 feet. Is the unit of feet not a measure of wavelength? Could I not use a furlong as a unit of length? I offer that ANY unit of length is acceptable in expressing wavelength. DD Hello OM, In the Navy my students learned at every level of instruction to: RTMFQ! That question was: name what frequency glare is. Now and then a student would come through who would respond "the frequency is such and such meters" as they passed out into the fleet as a deck-ape. 73's Richard Clark, KB7QHC |
#30
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On Wed, 07 Apr 2004 09:39:01 -0500, Cecil Moore
wrote: He said frequency and then turned around and used wavelength. Wavelength is also NOT a unit of frequency. His "elementary instruction" violated his own objection and was thus inconsistent. HE Knows both the Frequency AND the Wavelength and demonstrated you know neither. :-) |
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