How to get envelope from AM signal without phase shift
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From: WWalker on 30 Mar 2010 11:49 Eric, I agree that if the signal starts before the first filter and is then low pass filtered, the time delay of the signal is the propagation time plus the time delay of the filter. But what if the bandwidth limited signal is created directly without a low pass filter, then the the time delay is just the propagation time. For example, if the signal is created by a voltage source that is manualy slowly adjusted, such that the bandwidth is limited, and if the signal is then mixed with a carrier and sent though a nearfield dipole system, then the detected envelope will arrive earlier than a light propagated signal as I showed in my simulation. Each voltage point on the voltage vs time curve of the voltage source is information about what the voltage was at that time. If that pattern is reproduced exactly a distance away, then the time delay of each information point is the propagation time of the information. William >On 3/29/2010 3:15 PM, WWalker wrote: >> Eric, >> >> The first pulse is not the signal fed to the dipole. The first pulse is >> just used to create a narrow banded pulse, which is then sent through the >> dipole to be detected. Forget about the first pulse, the question is if I >> send a narrow banded pulse through the dipole how long will it take to >> arrive across a region of space in the nearfield of the dipole. If the >> answer is less than the speed of light to cross the same region of space, >> then the pulse has propagated faster than light. >> >> "So if press a button with the same signal characteristics as the LPF >> pulse, and if I use the threshold detector set jsut above the noise level >> to detect the pulse and explode a bomb, the bomb will explode earlier than >> if the pulse propagated at the speed of light. The pressing of the button >> (Action) results in the exploding of a bomb (Reaction) faster than light >> speed. This is clear cause and effect (information) which propagtes faster >> than light." >> >> >> William > >Okay, if you can't follow that argument (although it's still correct, >the narrow-band pulse peak isn't the information, or it's rise time >would be non-causal), then, as Glen pointed out, use your button push. > >If the button push is represented with an ideal impulse or a step >function, the rise time is the same (i.e., infinite). The narrow-band, >filtered representation of either an impulse or a step signal will have >delay, and the rise time will be proportional to the delay. The >narrower the filter, the longer the delay. > >The bandlimitation allows the possibility of prediction due to the >redundancy in the signal. Again, the same argument as before applies. > The delay through the bandlimiting filter (of the step response of the >button push) is X, a filter with negative group delay or other similar >predictive capability has a delay of X-delta WHICH IS STILL A POSITIVE >NUMBER. > >Measuring from the button push (or the incidence of an impulse, IT DOES >NOT MATTER), there will not be any acceleration of propagation beyond c, >just a reduction in filter delay in the predictive case. You can go >back a couple of days and many posts and see people suggesting to you to >measure either from signal onset or signal interruption, but you seem >unwilling to do this. I suspect you know what the result will be and >just refuse to let go of your theory. > >These are relatively simple arguments, especially to somebody who >insists on a competence level high enough to claim such an unlikely >explanation as exceeding c. > >-- >Eric Jacobsen >Minister of Algorithms >Abineau Communications >http://www.abineau.com >
From: WWalker on 30 Mar 2010 12:12 Jerry, The propagation distance in my 500MHz carrier simmulation is 10cm. But the distance can be a lot larger for lower carrier frequencies. For example, if the carrier frequency (fc) is 1MHz (typical AM radio) then the optimum propagation distance is 300m (1/6 carrier wavelength) and the envelope will arrive 80ns earlier than a light speed (propagating envelope (0.08/fc). For lower carrier frequencies, even larger distances and larger light speed time differences are possible. William >WWalker wrote: >> Eric, >> >> The first pulse is not the signal fed to the dipole. The first pulse is >> just used to create a narrow banded pulse, which is then sent through the >> dipole to be detected. Forget about the first pulse, the question is if I >> send a narrow banded pulse through the dipole how long will it take to >> arrive across a region of space in the nearfield of the dipole. If the >> answer is less than the speed of light to cross the same region of space, >> then the pulse has propagated faster than light. >> >> "So if press a button with the same signal characteristics as the LPF >> pulse, and if I use the threshold detector set jsut above the noise level >> to detect the pulse and explode a bomb, the bomb will explode earlier than >> if the pulse propagated at the speed of light. The pressing of the button >> (Action) results in the exploding of a bomb (Reaction) faster than light >> speed. This is clear cause and effect (information) which propagtes faster >> than light." > >Over what distance? > >Jerry >-- >Discovery consists of seeing what everybody has seen, and thinking what >nobody has thought. .. Albert Szent-Gyorgi >����������������������������������������������������������������������� >
From: WWalker on 30 Mar 2010 12:56 Rune, You are using insults and ridicule as arguments. Are you afraid to discuss this topic rationally? You obviously know a lot and I am sure you can contribute. Why don't you join us in the discussion. I told you I have measured the nonlinear phase responce of a magnetic dipole antenna using a RF Network analyser and it matches very well with the curve in figure 9 of my paper, also in the Sten Paper a NEC simulation shows the same results (Figure 3). There is no need to doubt the theory if: theory, simmulation, and experiment match. William >On 29 Mar, 23:25, "WWalker" <william.walker(a)n_o_s_p_a_m.imtek.de> >wrote: >> Rune, >> >> Now you are being rediculus! The dipole solution has been derived hundreds >> of times in hundreds of ways over the last 100 years. > >As I said, you are totally incompetent. The number of times >a solution has been derived is irrelevant. Whether it is correct >or not, makes all the difference in the world. Th eexpressions >you use are wrong in the near field. > >Answer me this: If the solution relies on the trivial exponential >functions - why do you spend time and space on discussing Bessel >functions? > >You don't know, because you haven't contemplated what happens. >You are merely a mysticist who thinks that reciting the prescribed >formulas is enough. > >Rune >
From: Jerry Avins on 30 Mar 2010 13:41 WWalker wrote: > Steve, > > If I place a grounded resistor (R) on the output of the nearfield dipole > dectector, then the signal voltage (V) will be converted to a current (I) > with the same signal shape as the transmitted signal. The power is > I*V = V^2/R and the energy is the the average power. This result is > proportional to how I demodulated my signal in my posted simulation, where > I squared the signal and low pass filtered it. > > William > > > >>> Steve, >>> >>> Clearly energy is also propagating faster than light in the dipole >> system. >>> If the pulsed carrier is propagating faster than light, as shown in my >>> simulaton, then the energy of this signal is just the signal squared and >>> low pass filtered. This is exactly how I detected the signal in my >>> simulation. So the detected pulse I showed in my simulation is also >>> proportional to the energy. >>> >>> William >> Squaring a signal to derive the power is based on assumptions about phase >> relationships. You are *inferring* power propagation. You are not >> demonstrating it. That's a leap needing justification. The E and H fields are in quadrature in the far field; thus the Poynting vector is normal to the wavefront and real power is conveyed. If I recall correctly, E and H are in phase in the near field and "power" is imaginary. Whatever power is developed in your resistor comes from the field being warped by the receiver, so the equations you use don't apply to the simulation. Jerry -- Discovery consists of seeing what everybody has seen, and thinking what nobody has thought. .. Albert Szent-Gyorgi �����������������������������������������������������������������������
From: Clay on 30 Mar 2010 13:58
On Mar 29, 12:18 pm, "WWalker" <william.walker(a)n_o_s_p_a_m.imtek.de> wrote: > Jerry, > > The speed of light is a corner stone in physics and if it is not a constant > then many of our theories in physics will be affected. There may be direct > practical uses as well, but I just guessing: improving accuracy of high > speed doppler radar, speeding up communication to spacecraft where time > delays are problematic, increasing speed of computers when they are > eventually limited by light speed delays etc. As I said, these are only > guesses, the main effect would be a change in many of our theories in > physics, which would eventually lead to new practical uses and > technologies. > > William > > > > >Eric Jacobsen wrote: > > > ... > > >> I think until you can demonstrate something like that the more likely > >> explanation of bandlimited prediction would be expected to prevail. > > >Even allowing the unlikely possibility that the 6-degree phase advance > >*in the near field* represents a real speed increase, and that the > >"pulse" in the far field is expected to show no advance at all, What > >practical use can this have? > > >Jerry > >-- > >Discovery consists of seeing what everybody has seen, and thinking what > >nobody has thought. .. Albert Szent-Gyorgi > >- Hide quoted text - > > - Show quoted text - Hello William, I suggest you 1st study the EPR paradox and then look up Bell's theorem and see how it applies to Relativity. You are not going to get information over any significant distance with superluminal speed. Sure there is a probability that a particle will travel faster than light for a short distance (say for example across the nucleus of an atom about 10^-14 to 10^-15 meters) but when you start to add up all of the paths in a Feynman diagram, you will see the probability of it happening across a room is not even likely in a time period of the age of the Universe. Clay |