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#91
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Dish reflector
On Wed, 15 Apr 2009 05:55:34 -0500, Cecil Moore
wrote: Richard Clark wrote: On Tue, 14 Apr 2009 20:35:00 -0500, Cecil Moore engaged in a conspiracy Hmm, Trilateral commission? It was tongue-in-cheek humor, Richard. Ah! That is what you thought I was thinking you were thinking I thought and you were wrong twice, right once and on the third hand was a draw. |
#92
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Dish reflector
On Wed, 15 Apr 2009 11:38:37 -0500, Cecil Moore
wrote: setup that I used to measure a ~25 nS delay through a 75m bugcatcher coil at 4 MHz. http://www.w5dxp.com/coiltest.GIF This is just a cartoon with the caption: "Magik happens here." |
#93
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Dish reflector
Cecil Moore wrote:
Jim Kelley wrote: And yet you keep posting your calculations and claiming to have made measurements. As have w7el and w8ji. All their measurements proved is that standing wave current doesn't change phase relative to the feedpoint current phase. They did not measure the delay through a coil. They measured the phase shift through the coil using a current that doesn't change phase relative to the two measurement points. The same thing happens with a wire. To measure the actual delay through a coil, traveling wave current must be used. I am apparently the only one who ran that actual experiment. I guarantee if anyone performs that experiment in a valid manner, they will see similar results to mine. Here's the setup that I used to measure a ~25 nS delay through a 75m bugcatcher coil at 4 MHz. http://www.w5dxp.com/coiltest.GIF You should be able to achieve that setup in your physics lab. Did you figure out the Z0 of your coil using the Tesla coil math, and then just assume there were no standing waves, or did you prove the absence of standing waves through experiment? 73, Tom Donaly, KA6RUH |
#94
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Dish reflector
On Wed, 15 Apr 2009 10:08:21 -0700, "Tom Donaly"
wrote: Cecil Moore wrote: they will see similar results to mine. Did you figure out the Z0 of your coil using the Tesla coil math, and then just assume there were no standing waves, or did you prove the absence of standing waves through experiment? Hi Tom, There is only the hint of a gejoken experiment. I notice nothing other than a cartoon, and nothing in the way of instrumentation described, much less the vaunted "results" (no doubt the final metaphysical tabulation came from some alchemistry). Certainly no antenna (nor dish reflector that matter). How it relates to a loaded short monopole would probably provoke an essay as elaborate as the coronation oratory for a pope. 73's Richard Clark, KB7QHC |
#95
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Dish reflector
Richard Clark wrote:
On Wed, 15 Apr 2009 10:08:21 -0700, "Tom Donaly" wrote: Cecil Moore wrote: they will see similar results to mine. Did you figure out the Z0 of your coil using the Tesla coil math, and then just assume there were no standing waves, or did you prove the absence of standing waves through experiment? Hi Tom, There is only the hint of a gejoken experiment. I notice nothing other than a cartoon, and nothing in the way of instrumentation described, much less the vaunted "results" (no doubt the final metaphysical tabulation came from some alchemistry). Certainly no antenna (nor dish reflector that matter). How it relates to a loaded short monopole would probably provoke an essay as elaborate as the coronation oratory for a pope. 73's Richard Clark, KB7QHC Hi Richard, Cecil has never been too effective when it comes to doing experiments. When asked to do math, he's even more sunk. I'm surprised he even managed to do a "gejoken" experiment. 73, Tom Donaly, KA6RUH |
#96
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Dish reflector
Tom Donaly wrote:
Did you figure out the Z0 of your coil using the Tesla coil math, and then just assume there were no standing waves, or did you prove the absence of standing waves through experiment? The standing waves don't have to be eliminated, just reduced until the traveling wave dominates the waveform. I added 600 ohm non-inductive resistors in series until the reflections were negligible and the traveling wave dominated the waveform. -- 73, Cecil, IEEE, OOTC, http://www.w5dxp.com |
#97
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Dish reflector
Richard Clark wrote:
I notice nothing other than a cartoon, ... I'm sorry if this seems like rocket science to you. I used toroidal pickups at the current sample points and viewed the current waveforms on a 100 MHz dual-trace oscilloscope. -- 73, Cecil, IEEE, OOTC, http://www.w5dxp.com |
#98
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Dish reflector
Cecil Moore wrote:
The standing waves don't have to be eliminated, just reduced until the traveling wave dominates the waveform. I added 600 ohm non-inductive resistors in series until the reflections were negligible and the traveling wave dominated the waveform. So why do you have to go to all that trouble when you want to measure traveling wave current, but not when you want to measure traveling wave energy? ac6xg |
#99
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Dish reflector
Jim Kelley wrote:
So why do you have to go to all that trouble when you want to measure traveling wave current, but not when you want to measure traveling wave energy? When one measures traveling wave energy, one is measuring an average calculated scalar value usually forward power minus reflected power or RMS V*I in a dummy load resistor. When one is measuring delay, one is measuring instantaneous traveling wave phase in real time. Trigger on the zero crossing of the input signal and measure the delay until the output signal crosses zero. That delay measurement doesn't work for standing- wave current because the zero-crossing on the input and output occur virtually simultaneously, i.e. there is no relative phase shift between input and output or between any two points on a 1/4WL wire monopole. -- 73, Cecil, IEEE, OOTC, http://www.w5dxp.com |
#100
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Dish reflector
On Wed, 15 Apr 2009 15:18:51 -0500, Cecil Moore
wrote: Richard Clark wrote: I notice nothing other than a cartoon, ... I'm sorry if this seems like rocket science to you. And this from the cartoonist. It readily explains how poorly the gejoken experiment started. Let's see how many yuks it will get through conventional issues I used toroidal pickups at the current sample points and viewed the current waveforms on a 100 MHz dual-trace oscilloscope. No mention of make, no readings, no pretense at discussion of those things that contribute to error (and, as such, no need for Cecil to apologize for being wrong until he is painted into his usual corner). So, from this sloppiness called anyone performs that experiment in a valid manner, I suppose I have to fill in the blanks and watch Cecil sputter that it wasn't like that at ALL!!! The cartoonist is most comfortable in simple things, certainly; but measurement is best left to professionals. measure a ~25 nS delay which is the same as a 40 MHz event, but in some "100 MHz" scopes, and depending upon a myriad of settings (anyone practiced in the art would realize how many), signal amplitude being one; that same BW can tumble to 20 MHz to the unsuspecting user's surprise (Cecil can now react in mock surprised shock). With a roll-off of 3dB per octave (another concept that is foreign to digital engineers, such is Cecil's legacy), phase measurement errors begin to run away. We don't even get the Sunday comics form of math! OK, so measure a ~25 nS delay is so much of a hodge-podge, a place marker, a spit into the wind, something summoned up for the unwashed so the author could bask in their awe-shucks. If we were to simply accept it (GASP!), what does it say of the delay introduction of the toroidal pickups at the current sample points More magik happens here no doubt. I won't ask Cecil what his data is for these items because he doesn't have any (at least until he rummages up the dutch courage to fake it). And what about the phase issues of the 4000 Ohm resistor (which conveniently snubs what might be found in the rest of the antenna now long discarded such that this becomes an onanistic exercise)? Again, no point in asking for data that doesn't exist (you can't even fake it). Magik abounds because Cecil's best work is cartoonistry, not science, and certainly not rocket science. So, a very quick enumeration of points any experimenter would have come into the discussion with, rather than trailing behind like a dancing bear with blisters. But I like gejoken experiments, and Cecil's clowning offers the dovetail to Art's when he isn't here complaining about the nails in his hands. I would give this, maybe, 3 yuks. 73's Richard Clark, KB7QHC |
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