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On Sun, 23 May 2004 17:18:52 GMT, "Henry Kolesnik"
wrote: OK, if we shine a flashlight at a mirror the light bounces back and what ever is caught by the reflector will be reflected. Take away the reflector and the reflection just keeps going. If someone can tell me what the hot filament does perhaps I can understand what happens in the finals, or whatever. tnx Hank WD5JFR Hi Hank, Well I see in correspondence following this as "replies," that they are far from satisfactory. All part of the arcana that precedes the convolutions of math you would have had to endure. The abandonment of this lead is simply a matter of Cecil's lack of experience in the metaphor of light. To answer your question above. Removing the reflector is unnecessary as it is part of the initial condition and has nothing to do with it serving as the correlative to a tuner that you want to remove from the argument (which is a perfectly acceptable imposition of conditions). Your question also goes to the heart of the matter. We begin with a hot filament which emits radiation (and yes, no reflector is required so we will skip that as one of your conditions). The amount of radiation is directly correlated to the amount of heat. This will simplify matters, but in the end it will yield a failure of metaphors (which always occur if you cannot bridge the logic). The radiation strikes a reflection (immaterial whether complete or partial) and that portion which returns, impinges upon the filament, the source. The filament absorbs the power, which in turn raises its temperature (everyday experience proves the heat of such radiation). This will, in turn, cause a higher radiation (given the quid-pro-quo of heat and radiation). In a sense, this means the reflected power is re-radiated. The confirmation of this is that if you achieved full reflection, you then define total insulation of the radiation (no heat escapes) and temperature rises accordingly, and this may lead to catastrophic failure of the filament (a very bright illumination if you could see it, and consequent fusing current - electric kilns use this principle but tolerate the current by under rating the source). You can imagine the correlative to transmitter failure for the same conditions. The failure of the metaphor? RF is not heat (common light is) and the return of power to be rendered into heat does not result in a higher RF output. I will anticipate the sophomore's comments that RF reflections do not become heat, in and of itself: The returned power (either through wave mechanics or lumped circuitry) must result in either a higher potential across the source, or a higher current through it. Elevated potentials yield the everyday experience of an arc (heat). Elevated currents yield the everyday experience of current density through the same element (much like the filament of our metaphor - heat). One failure mode comes with the peak power snap, followed by the muttering of "Oh ****!" Or it comes through the more progressive thermal runaway, followed by the muttering of "what's that funny smell?" 73's Richard Clark, KB7QHC |
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