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skin depth decay
For a moment I can ignore the capacitive and inductive constituents
of a radiator and concentrate on "skin depth" Ignoring my premise that the surface is covered with free electrons that are expelled from a energy storage system. I look at a piece of aluminum as a raw material which is measured and placed within a vacuum. Since it is accepted that skin depth is a volume that is decaying it would appear that the loss of this volume could be a subject of measurement. By the same token we could remove a radiator from an array and also place that part after measurement to quantisize the .. the amount of decay and compare the differences. We could then examine the decayed remanants to determine its properties. Has this been done and what were the findings? This would certainly help it determining how the material forming the skin got there in the first place! Question arise whether the skin material comes from the atmosphere or from a regenerative property of the material itself thus ruling out the sino soidal applied energy. .( Ignoring the obvious question as to how the energy got past the capacitance while retaining it's initial properties). Bear in mind that present calculations are based on the understanding that a sino soidal current is present at every segment point that can be chosen which then allows the presence of a time variant at each and every point on a radiator.(This an alternative to my viewing the radiator as a tank circuit) Ofcourse if you already know of a book that shows how the skin surface materialises from the beginning and methodically replaced as it moves from the surface to the innards of the radiator, please let me know. Regards Art |
skin depth decay
No !!!!!!!!!
Every thing is known. It must be in the books of Kraus and you know who. I keep reading that the theories of radiation is well known and widely accepted, so what is widely accepted in this area? Is the "rust" of aluminium called bauxite by any chance? And is it diamagnetic? Art Christopher Cox wrote: Sputtering? BTW, lots of luck with that subject, it would seem there is little understanding on the field of study other than it works. |
skin depth decay
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skin depth decay
Thank you for the info John.
I am not very good in the chemical area but I believe that all diamagnetic materials form hydroxides where the constituents contain a sinle Oygen and hydrogen (HO) Thus materials used for antennas generate a surface where (HO) is a constituent. This can produce particles,ions or what have you to congregate on the surface but without energy per se but possibly adverse to the high velocity release of electrons. Would that have any accurate deductions derived from the initial (HO) constituent? I also see a possibility that all contain a particular static particle such as dust that can be obtained from most if not all orbiting mass in the Universe ( something like Moon dust that cling to a astronauts outer wear in the effort to join the H2O of the human body within) I did read that NASA in an effort to remove moon dust had partial success by directing energy from a capacitor release which overcame the inertia of the dust on clothing.(They have a fear of this dust entering the space vehicle and acting as an abrasive substance.) As you may guess I am trying to determine the action of a pulsatic release of energy from a capacitor that will eject "something" from a diagmagnetic surface from which a radiator is made. Again, many thanks Art Unwin KB9MZ.....xg John Passaneau wrote: art wrote in news:09534116-d261-4f5d-aeea- : No !!!!!!!!! Every thing is known. It must be in the books of Kraus and you know who. I keep reading that the theories of radiation is well known and widely accepted, so what is widely accepted in this area? Is the "rust" of aluminum called bauxite by any chance? And is it diamagnetic? Art Christopher Cox wrote: Sputtering? BTW, lots of luck with that subject, it would seem there is little understanding on the field of study other than it works. The "rust" on aluminum is aluminum oxide. More related to Corundum {Al2O3}, sorry can't do subscripts in thunderbird, than Bauxite which is {Al2O3.2H2O}. The oxide coating forms almost instantly on aluminum when exposed to air. It is very thin and can be scratched off and will not form if air is keep away from it which is why clamping works. The oxide coating is also why soldering to aluminum is hard to do. If soldered in an atmosphere without oxygen aluminum would solder easily. When aluminum is exposed to water a white powdery coating forms. That is closer to Bauxite as it�s a hydrated aluminum oxide of which Bauxite is just one. Anodizing is process that makes the aluminum oxide coating thicker and more porous so that dye can be forced into it so it can be colored. And anodizing also is a good insulator which is why it must be scraped off where you want to make an electrical connection. John Passaneau Penn State University |
skin depth decay
On Thu, 15 Nov 2007 11:01:39 -0800 (PST), art
wrote: As you may guess I am trying to determine the action of a pulsatic release of energy from a capacitor that will eject "something" from a diagmagnetic surface from which a radiator is made. Hi Arthur, This is discussed in most Physics books. Unfortunately, not in the terms you are expecting - so essentially trash to any invention purporting to elevate this dust-buster energy to radiation status. Let's say you want to pulsatic eject "something" from a surface. It first has to exceed the work function of the material. This is pretty hard for metals exposed to any environment other than vacuum, and even more hard if insufficient voltage/temperature is applied. Given this work function barrier, we would observe it as the cessation of radiation from an antenna when potentials/temperatures dropped below a critical level. Given further that many Ham operators collect QSL cards from all over the planet on Watt power levels, there is no evidence of this at all (as a Watt power level into a resonant dipole is insufficient to supply the work function requirement). Hence, it follows that pulsatic ejection is of no consequence beyond the illusion of performance. 73's Richard Clark, KB7QHC |
skin depth decay
I am beginning to believe that levitation is at hand here.
When a magnetic fiels is imposed particles on the surface of the radiator are levitated where they MUST move to the outside of the arbitary border from Gauss which encloses the aluminum radiator and the static particles. The magnetic field upsets the equilibrium within the confined border where the border fractures in an effort to retain equilibrium which allows for full levitation outside the border Do some articles that are in the motion of levitation fail to escape when the magnetic fields is lost and thus return to the radiators surface possibly to replace particles lost from the "skin" of the radiator. I think we have a possible avenue here! Art Unwin KB9MZ....XG art wrote: Thank you for the info John. I am not very good in the chemical area but I believe that all diamagnetic materials form hydroxides where the constituents contain a sinle Oygen and hydrogen (HO) Thus materials used for antennas generate a surface where (HO) is a constituent. This can produce particles,ions or what have you to congregate on the surface but without energy per se but possibly adverse to the high velocity release of electrons. Would that have any accurate deductions derived from the initial (HO) constituent? I also see a possibility that all contain a particular static particle such as dust that can be obtained from most if not all orbiting mass in the Universe ( something like Moon dust that cling to a astronauts outer wear in the effort to join the H2O of the human body within) I did read that NASA in an effort to remove moon dust had partial success by directing energy from a capacitor release which overcame the inertia of the dust on clothing.(They have a fear of this dust entering the space vehicle and acting as an abrasive substance.) As you may guess I am trying to determine the action of a pulsatic release of energy from a capacitor that will eject "something" from a diagmagnetic surface from which a radiator is made. Again, many thanks Art Unwin KB9MZ.....xg John Passaneau wrote: art wrote in news:09534116-d261-4f5d-aeea- : No !!!!!!!!! Every thing is known. It must be in the books of Kraus and you know who. I keep reading that the theories of radiation is well known and widely accepted, so what is widely accepted in this area? Is the "rust" of aluminum called bauxite by any chance? And is it diamagnetic? Art Christopher Cox wrote: Sputtering? BTW, lots of luck with that subject, it would seem there is little understanding on the field of study other than it works. The "rust" on aluminum is aluminum oxide. More related to Corundum {Al2O3}, sorry can't do subscripts in thunderbird, than Bauxite which is {Al2O3.2H2O}. The oxide coating forms almost instantly on aluminum when exposed to air. It is very thin and can be scratched off and will not form if air is keep away from it which is why clamping works. The oxide coating is also why soldering to aluminum is hard to do. If soldered in an atmosphere without oxygen aluminum would solder easily. When aluminum is exposed to water a white powdery coating forms. That is closer to Bauxite as it�s a hydrated aluminum oxide of which Bauxite is just one. Anodizing is process that makes the aluminum oxide coating thicker and more porous so that dye can be forced into it so it can be colored. And anodizing also is a good insulator which is why it must be scraped off where you want to make an electrical connection. John Passaneau Penn State University |
skin depth decay
On 15 Nov, 19:51, Christopher Cox
wrote: I guess Art was implying sputtering. I actually posted the response sort of "tongue in cheek". It was my understanding sputtering requires a vacuum and high voltage. It would appear by Art's response, they figured out all the ins and outs of sputtering. Chris Richard Clark wrote: On Thu, 15 Nov 2007 11:01:39 -0800 (PST), art wrote: As you may guess I am trying to determine the action of a pulsatic release of energy from a capacitor that will eject "something" from a diagmagnetic surface from which a radiator is made. Hi Arthur, This is discussed in most Physics books. Unfortunately, not in the terms you are expecting - so essentially trash to any invention purporting to elevate this dust-buster energy to radiation status. Let's say you want to pulsatic eject "something" from a surface. It first has to exceed the work function of the material. This is pretty hard for metals exposed to any environment other than vacuum, and even more hard if insufficient voltage/temperature is applied. Given this work function barrier, we would observe it as the cessation of radiation from an antenna when potentials/temperatures dropped below a critical level. Given further that many Ham operators collect QSL cards from all over the planet on Watt power levels, there is no evidence of this at all (as a Watt power level into a resonant dipole is insufficient to supply the work function requirement). Hence, it follows that pulsatic ejection is of no consequence beyond the illusion of performance. 73's Richard Clark, KB7QHC- Hide quoted text - - Show quoted text - No Chris I know you are not refering to the other use of a 8877 ie spluttering as with reed switch contacts. When a time varing current toapplied to something that creats radiation I am trying to deduce an alternative to the thinking that current can hurdle a capacitor and retain it's time varience. This is why I view it in the context of adding a time varient to the laws of static particles where this action results in a tank circuit. In that case the pulsatic release of energy serves as a time varient that satisfies the laws of Maxwell without the assumption that current can leap frog a capacitor. (Roy states that this is something he doesn't understand, as well as avoiding mechanical laws since they are irrelavent in the electrical world) Whether I will be succesful in presenting a realistic alternative to jumping currents is moot . But after successfully produced an antenna, not a system, that exceeds that which follows printed theories I think I can be forgiven in not just accepting but to also pursue an understanding. Certainly, I must not pursue the idea of distributed capacitance is completly devoid of ALL characteristics of a lumped capacitance as the computor programmers would have us believe ! Food for thought for those without the herd mentallity who tend to dismiss the "unlikely" and make their fortune on only betting on polled favorites at any racing event....! I do like the thought of levitation since it fits in the idea of a Gaussian field because then the escaping/ ejected particle meet the same conditions that create levitation when in the vicinity of a diamagnetic material ala a radiator. Question remains tho that particles are removed from the arbitary field possibly skin particles. This suggest then than that radiator surfaces are resealed on the surface from that provided from the external capacitor. All in all something worth while to ponder upon Best regards Art Unwin....KB9MZ |
skin depth decay
Art wrote:
"I am trying to deduce an alternative to the thinking current can hurdle a capacitor and retain its time variation." An early demonstration of electroostatic repulsion was via an instrument called the electroscope. Put a charge on its plates and it opened like a book. It proved like charges repelled and that repulsion was proportional to charge. From that it can be imagined that if you put a charge on one insulated plate and like charges on an insulated plate nearby have an avenue of escape to the outside world, you may have produced a capacitor useful for ac coupling or bypass. It isn`t a hurdle. It is a device capable of a displacement current which blocks dc but passes ac. It`s a device formerly called a condenser, now called a capacitor. Best regards, Richard Harrison, KB5WZI |
skin depth decay
"Richard Harrison" wrote in message ... Art wrote: "I am trying to deduce an alternative to the thinking current can hurdle a capacitor and retain its time variation." An early demonstration of electroostatic repulsion was via an instrument called the electroscope. Put a charge on its plates and it opened like a book. It proved like charges repelled and that repulsion was proportional to charge. From that it can be imagined that if you put a charge on one insulated plate and like charges on an insulated plate nearby have an avenue of escape to the outside world, you may have produced a capacitor useful for ac coupling or bypass. It isn`t a hurdle. It is a device capable of a displacement current which blocks dc but passes ac. It`s a device formerly called a condenser, now called a capacitor. Best regards, Richard Harrison, KB5WZI just wait till he tries to tell you that the plates have to be diamagnetic so his fictional static particles can jump off the plate. i quit watching his direct responses after he couldn't explain why ferro magnetic plates wouldn't work when it is well known that they will. |
skin depth decay
"Christopher Cox" wrote I guess Art was implying sputtering. I actually posted the response sort of "tongue in cheek". It was my understanding sputtering requires a vacuum and high voltage. It would appear by Art's response, they figured out all the ins and outs of sputtering. Chris: Sputtering and blithering is what Art does best! Mike W5CHR |
skin depth decay
On 16 Nov, 07:06, (Richard Harrison) wrote:
Art wrote: "I am trying to deduce an alternative to the thinking current can hurdle a capacitor and retain its time variation." An early demonstration of electroostatic repulsion was via an instrument called the electroscope. Put a charge on its plates and it opened like a book. It proved like charges repelled and that repulsion was proportional to charge. From that it can be imagined that if you put a charge on one insulated plate and like charges on an insulated plate nearby have an avenue of escape to the outside world, you may have produced a capacitor useful for ac coupling or bypass. It isn`t a hurdle. It is a device capable of a displacement current which blocks dc but passes ac. It`s a device formerly called a condenser, now called a capacitor. Best regards, Richard Harrison, KB5WZI I assume you are not trying to be funny and are using the dictates of Terman to make a point. So I will respond. The antenna am referring to consists of a tank circuit where the distributed capacitance is the capacitor in the circuit. The capacitor stores energy from the time varying current and then releases the energy when the terminals are shorted. This energy is not released with the same properties that the capacitor but in a similar way that a battery does when the terminals are shorted. Thus the time variant that one sees on the energy release is not the same as the time varient possesed when delivered to the capacitor but I could be in error. I have most of Termans books so if you can point to a section that confirms your position and contradicts mine I would apreciate if you would share that section with me. Regards Art |
skin depth decay
On 16 Nov, 07:06, (Richard Harrison) wrote:
Art wrote: "I am trying to deduce an alternative to the thinking current can hurdle a capacitor and retain its time variation." An early demonstration of electroostatic repulsion was via an instrument called the electroscope. Put a charge on its plates and it opened like a book. It proved like charges repelled and that repulsion was proportional to charge. From that it can be imagined that if you put a charge on one insulated plate and like charges on an insulated plate nearby have an avenue of escape to the outside world, you may have produced a capacitor useful for ac coupling or bypass. It isn`t a hurdle. It is a device capable of a displacement current which blocks dc but passes ac. It`s a device formerly called a condenser, now called a capacitor. Best regards, Richard Harrison, KB5WZI What you must understand is t5he circuit that constitutes a capacitor part of which is a resister that is seen in parallel. So yes, a portion of energy can bypass the capacitor. However the time varient that one must measure is at best, a superinposed expellation of energy from the capacitor which changes the original time varient required for radiation. Cecil makes the point he can measure the current along the radiator, but in fact he has a measuring problem by what he is using to measure current with respect to time. Regards Art |
skin depth decay
Art wrote:
"What you nust understand is the circuit that constitutes a capacitor part of which is a resistor that is seen in parallel." That would be equivalent to a leaky capacitor. There is no time delay in a pure resistor. Its voltage drop is in-phase with the current through it. I don`t have a complete equivalent circuit in mind. Best regards, Richard Harrison, KB5WZI |
skin depth decay
On 17 Nov, 16:57, (Richard Harrison) wrote:
Art wrote: "What you nust understand is the circuit that constitutes a capacitor part of which is a resistor that is seen in parallel." That would be equivalent to a leaky capacitor. There is no time delay in a pure resistor. Its voltage drop is in-phase with the current through it. I don`t have a complete equivalent circuit in mind. Best regards, Richard Harrison, KB5WZI Right. The the sino soidal shape will go thru with its time varient which is the condition applied by programmers for EVERY segment. But that is only half the story for a TANK circuit. The capacitor stores energy just like charging a battery, it will not NOT thru. When the situation is right the capacitor/battery releases all its energy like connecting a terminal to ground or shorting it.This allows the energy to flow in dc format at a rate decides by its time constant ot time varient required for radiation. This energy release is imposed on the leakage current thus forming a new time varient rquirede for radiation. Thus at different segment points the time varient is not a reflection of a sino soidal leakage current but the summation of that PLUS the capacitor dicharge time constant. Look up a tank circuit and all will become clear when you follow the phase changes of the voltage and the current first in forward direction and then the reverse direction. Regards Art |
skin depth decay
Art wrote:
"When the situation is right the capacitor/battery releases all its energy like connecting a terminal to ground or shorting it." Not quite. The inductance, whose reactance equals the capacitance`s reactance at resonance, opposes any change in current. It only allows current to grow exponentially during the cycle by simultaneously generating a counter emf to oppose the current imposed on the inductance from outside. The impressed current will lag the voltage across a pure inductance by 90 degrees. The voltage builds across a pure capacitance with a 90 degree lag of the current through the capacitance. This is basic electricity 101. Best regards, Richard Harrison, KB5WZI |
skin depth decay
On 18 Nov, 19:00, (Richard Harrison) wrote:
Art wrote: "When the situation is right the capacitor/battery releases all its energy like connecting a terminal to ground or shorting it." Not quite. The inductance, whose reactance equals the capacitance`s reactance at resonance, opposes any change in current. It only allows current to grow exponentially during the cycle by simultaneously generating a counter emf to oppose the current imposed on the inductance from outside. The impressed current will lag the voltage across a pure inductance by 90 degrees. The voltage builds across a pure capacitance with a 90 degree lag of the current through the capacitance. This is basic electricity 101. Maybe in America! Since it is resonant then it is a tank circuit where you have to rethink the 90 degree lag Art Best regards, Richard Harrison, KB5WZI |
skin depth decay
Richard Harrison wrote:
Art wrote: "When the situation is right the capacitor/battery releases all its energy like connecting a terminal to ground or shorting it." Not quite. The inductance, whose reactance equals the capacitance`s reactance at resonance, opposes any change in current. It only allows current to grow exponentially during the cycle by simultaneously generating a counter emf to oppose the current imposed on the inductance from outside. The impressed current will lag the voltage across a pure inductance by 90 degrees. The voltage builds across a pure capacitance with a 90 degree lag of the current through the capacitance. This is basic electricity 101. A little too basic, I'm afraid. The 90 degree current lag applies only to a steady state sinusoidal voltage. For other waveforms (like ones you'd get connecting batteries or capacitors) you have to resort to the more general time relationship v = L * di/dt. (Or, if inductance is changing with time, v = d/dt (L * i).) Roy Lewallen, W7EL |
skin depth decay
Roy Lewallen wrote:
"S little too basic, I`m afraid. The 90 degree current lag applies only to a steady state sinusoidal voltage." A steady state sinusoidal voltage is exactly what I would expect on a resonant antenna in the absence of modulation when a carrier has been applied to the antenna for a short but not too short period of time. Best regards, Richard Harrison, KB5WZI |
skin depth decay
On 20 Nov, 00:07, "Jimmie D" wrote:
"Richard Harrison" wrote in message ... Roy Lewallen wrote: "S little too basic, I`m afraid. The 90 degree current lag applies only to a steady state sinusoidal voltage." A steady state sinusoidal voltage is exactly what I would expect on a resonant antenna in the absence of modulation when a carrier has been applied to the antenna for a short but not too short period of time. Best regards, Richard Harrison, KB5WZI The peril of trying to actualy answer Art's questions. Richard can be excused for making this error. This is the same fundamental reason that Ted Hart, Professor Underhill and lately Vincent failed to design a radiator that actually works efficiently. And to this day they and the ham world are totally oblivious as to why. This is a direct effect of memorizing facts in college without regard to first principles to obtain a degree. Pretty much all examinations I had to take in Europe demanded a response to a question using only first principles to avoid failure. Where failure in any subject during the year required a repeat of all subjects taken that year, even those where a pass was obtained, where one has to be successfull, or thrown out! Art Unwin KB9MZ....xg (UK) |
skin depth decay
Art wrote:
"Richard can be excused for making this error." Prove I erred! Put a sine wave in an antenna and you get a sine wave out. Kraus says: "The currents on the transmission line flow out on the antenna and end there, but the fields associated with them keep on going." Art in a previous posting said I should quote "Lady Chatterley`s Lover" as people were tiring of Terman. I read it before it was even printed in the U.K. (1960) but this is an antenna newsgroup and Terman is more appropriate. If people want something other than Terman, he gives a terrific bibliography at the bottom of page 864 in his 1955 opus. Art also said in a previous posting that Terman did not credit Maxwell with defining radiation. Let me put the lie to that. On page 864 of his 1955 opus, Terman writes: "The laws governing such radiation are obtained by using Maxwell`s equations to express the fields associated with the wire; when this is done there is found to be a component, termed the radiated field having a strength that varies inversely with the distance." Best regards, Richard Harrison, KB5WZI |
skin depth decay
On 20 Nov, 08:47, (Richard Harrison) wrote:
Art wrote: "Richard can be excused for making this error." Prove I erred! Roy pointed it out not I. He can be more specific to what he was pointing out. I have no wish to explain on his behalf Put a sine wave in an antenna and you get a sine wave out. Very true Kraus says: "The currents on the transmission line flow out on the antenna and end there, but the fields associated with them keep on going." Could be Art in a previous posting said I should quote "Lady Chatterley`s Lover" as people were tiring of Terman. I read it before it was even printed in the U.K. (1960) but this is an antenna newsgroup and Terman is more appropriate. But I have never read it! I don't believe I pointed to " Maxwell" but all of the scientists involved with radiation, and there are many. I didn't make a point of searching for the names just don't recall seeing them. If people want something other than Terman, he gives a terrific bibliography at the bottom of page 864 in his 1955 opus. I will take a look at that Art also said in a previous posting that Terman did not credit Maxwell with defining radiation. Let me put the lie to that. On page 864 of his1955 opus, Terman writes: "The laws governing such radiation are obtained by using Maxwell`s equations to express the fields associated with the wire; when this is done there is found to be a component, termed the radiated field having a strength that varies inversely with the distance." Best regards, Richard Harrison, KB5WZI Have a happy harvest festival, the name assigned before the Americans changed the name. I woinder when the word "thanksgiving" came into being? |
skin depth decay
Richard Harrison wrote:
Kraus says: "The currents on the transmission line flow out on the antenna and end there, but the fields associated with them keep on going." Actually, in a standing-wave antenna, such as a 1/2WL dipole, the antenna wave currents bounce back and forth between the open ends and the feedpoint. If there is not a Z0-match to the feedline at the feedpoint, some of the antenna current reflected from the open end of the antenna leaks back into the feedline and makes it's way back to the source. A TDR will register reflections both from the feedpoint and the open ends of the antenna. -- 73, Cecil http://www.w5dxp.com |
Thanksgiving
art wrote:
Have a happy harvest festival, the name assigned before the Americans changed the name. I wonder when the word "thanksgiving" came into being? http://showcase.netins.net/web/creat...hes/thanks.htm 73, jk |
skin depth decay
On 20 Nov, 10:58, Cecil Moore wrote:
Richard Harrison wrote: Kraus says: "The currents on the transmission line flow out on the antenna and end there, but the fields associated with them keep on going." Actually, in a standing-wave antenna, such as a 1/2WL dipole, the antenna wave currents bounce back and forth between the open ends and the feedpoint. If there is not a Z0-match to the feedline at the feedpoint, some of the antenna current reflected from the open end of the antenna leaks back into the feedline and makes it's way back to the source. A TDR will register reflections both from the feedpoint and the open ends of the antenna. -- 73, Cecil http://www.w5dxp.com An antenna I played with years ago was a sample of this search by current flow. It was a dipole where the center was a closed loop.The low current curve stated at the end of the dipole and moves to the loop where it will circulate until the match is right for it to travel on to the other end of the dipole to achieve a low current point which is required for resonance. The machanical analogy of this is a mechanical rotary pump where it deals with shear and cavitation of water flow. But I don't think that is what Roy was alluding to as much as it was a failure of understanding with respect to current and voltage phase. But I will have to wait and see what Roy meant. Regards Art Unwin KB9MZ....XG |
Thanksgiving
Jim Kelley supplied the URL of Lincoln`s Thanksgiving Day proclamation
during the American Civil War. It goes back much before Lincoln. Thanksgiving predates the joint celebration of English colonists and American Indians at Plymouth in 1621. Thanksgiving gatherings have occurred throughout the world and throughout history. In America, the natives traditionally had several of these festivals a year long before the Europeans arrived. The English colonists did not call the 1621 event a "thanksgiving". They actually had their first thanksgiving in the summer of 1623 for rain which ended a long drought. Happy Thabksgiving! Best regards, Richard Harrison, KB5WZI |
skin depth decay
Cecil, W5DXP wrote:
"A TDR will register reflections both from the feedpoint and the open ends of the antennas." Why reflections from the feedpoint if the antenna matches the feedline? Best regards, Richard Harrison, KB5WZI |
Thanksgiving
On 20 Nov, 12:34, Jim Kelley wrote:
art wrote: Have a happy harvest festival, the name assigned before the Americans changed the name. I wonder when the word "thanksgiving" came into being? http://showcase.netins.net/web/creat...hes/thanks.htm 73, jk Interesting. My first observance of Harvest festival when my church had products that had been harvested from the earth on every surface that was flat. These products were given to the poor who lived rent free on grounds owned by the church. At the same time King George dished out special coins known as "Maunday" money since he was head of the Church of England courtesy of Henry VIII.Since it was puritans that first settled in America I suspect that the church function was also connected to the Catholic church heritage. Looks like Lincoln rolled it into one celebration after the Civil War tho it is suggestive that the church holiday was in position before then but with the name unknown. Thanks JK Art |
skin depth decay
Richard Harrison wrote:
Cecil, W5DXP wrote: "A TDR will register reflections both from the feedpoint and the open ends of the antennas." Why reflections from the feedpoint if the antenna matches the feedline? If the antenna is fed with 50 ohm coax, the antenna does not match the feedline. The Z0 of a #14 wire 30 feet in the air is ~600 ohms. It takes a half-cycle of sinusoidal RF for the feedpoint impedance to begin to match the coax Z0, i.e. the feedpoint impedance of a standing wave dipole is a virtual impedance that doesn't exist until the first reflections arrive from the ends of the antenna. Before Reg died, he had something to say about that. -- 73, Cecil http://www.w5dxp.com |
skin depth decay
I wrote:
"The impressed current will lag the voltage across a pure inductance by 90 degrees." Roy wrote: "For other waveforms (like the ones you`d get connecting batteries or capacitors) you have to resort to the more general time relationship L*di/dt. Roy is correct for connecting batteries or capacitors but Art was working wih a lengthy antenna, not a lone elementary segment. He also had no step functions, just a sine wave driving his antenna. Best regards, Richard Harrison, KB5WZI |
skin depth decay
Cecil, W5DXP wrote:
"If the antenna is fed with 50 ohm coax, the antenna does not match the feedline." I get the picture. everal iterations are needed to reach a match. But, it all happens so fast there is little practical significance. Best regards, Tichard Harrison, KB5WZI |
skin depth decay
In article ,
Cecil Moore wrote: Why reflections from the feedpoint if the antenna matches the feedline? If the antenna is fed with 50 ohm coax, the antenna does not match the feedline. The Z0 of a #14 wire 30 feet in the air is ~600 ohms. It takes a half-cycle of sinusoidal RF for the feedpoint impedance to begin to match the coax Z0, i.e. the feedpoint impedance of a standing wave dipole is a virtual impedance that doesn't exist until the first reflections arrive from the ends of the antenna. Before Reg died, he had something to say about that. In the back of "TV and Other Receiving Antennas" by Arnold Bailey is an interesting section which describes a large number of commonly-used TV antenna configurations - dipoles made of wire and rod, folded dipoles with various wire diameters and spacings, bot-tie, simple Yagi, and so forth. For each such, Bailey gives two impedance figures - the "surge" impedance and the feedpoint impedance - which I believe correspond to the two impedances Cecil is referring to (i.e. before, and after the standing wave is established). It's an interesting book... out of print for years, and not (as far as I know) available electronically. -- Dave Platt AE6EO Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior I do _not_ wish to receive unsolicited commercial email, and I will boycott any company which has the gall to send me such ads! |
skin depth decay
On 20 Nov, 16:02, (Richard Harrison) wrote:
I wrote: "The impressed current will lag the voltage across a pure inductance by 90 degrees." Roy wrote: "For other waveforms (like the ones you`d get connecting batteries or capacitors) you have to resort to the more general time relationship L*di/dt. Roy is correct for connecting batteries or capacitors but Art was working wih a lengthy antenna, not a lone elementary segment. He also had no step functions, just a sine wave driving his antenna. Best regards, Richard Harrison, KB5WZI Oh Richard, you may deny my antenna but that is what I was alluding to. Again it is the LC ratio thatmust be kept for resonance. The importance of these are their characteristics as storage containers of energy the release of which is determined by their time constant. Both release their energy in turn to remove static particles from the surface of the radiator in a similar way to a battery at the time of explosion.( Note the battery comment which is what you responded to} This is the time varient required for radiation that the masters disclosed but without pertinent details. This started when the Gaussian law of statics was shown by me to equate to the laws founded by Maxwell. SO WHAT was the thread that then dominated. But for me it was not the marrying of Gauss to Maxwell it was the journey taken in pursuit of knoweledge that could only be revealed by walking in the same shoes that Gauss would have done if he had not deserted mathematics. The journey shows evidence that static particles are at rest on a radiators surface. It also provides evidence that radiators with respect to Maxwells teachings are a wavelength long and in equilibrium when placed with static particles in a arbitary border. It then points to the logic of the time varient mentioned by the masters was NOT the sino soidal current provided but instead the explosion type release of energy from the inherrent storage containers. True sino soidal current runs around the circuit but only because a bypass resister is present with all capacitors. This bypass current is extremely small compared to the energy blast from a energy container. By the same token for equilibrium to be maintained the LC ratio must be kept to simulate the action of a pendulum and its occillations. Now the above is revealed not by the proof of the final calculations but from all that is observed during the required journey., From the above it becomes obvious that the condition added by programmers was not only a fraud but also incorrect when the condition was added to existing law (which is fraudulent. When this inaccurate condition is removed and Maqxwells laws adhered to the errors generated by this false addition will disappear. From the above it can now be said that a radiator can be any shape or variety of elevation as long as it is in equilibrium (ala a wavelength long) where it can provide a lossless means of radiation when disregarding frictional losses of the circuit. It is also impotant to note that if the inductive energy level container is made larger at the same time holding to the LC ratio then the time constant required for radiation will increase. So think again when you wish to say "So What" since the above will become a lasting acceptance of science regardless of the baying crowd of this newsgroup that want to depart to newer aproaches that describe the Universe. Oh, and another side comment, I have a rotatable top band antenna on the top of by tower using the nsame principles alluded to above and yes it is directional and does not require a ground plain to attain equilibrium. Have a happy day Art Unwin ....KB9MZ..XG (uk) |
skin depth decay
On 20 Nov, 16:23, (Dave Platt) wrote:
In article , Cecil Moore wrote: Why reflections from the feedpoint if the antenna matches the feedline? If the antenna is fed with 50 ohm coax, the antenna does not match the feedline. The Z0 of a #14 wire 30 feet in the air is ~600 ohms. It takes a half-cycle of sinusoidal RF for the feedpoint impedance to begin to match the coax Z0, i.e. the feedpoint impedance of a standing wave dipole is a virtual impedance that doesn't exist until the first reflections arrive from the ends of the antenna. Before Reg died, he had something to say about that. In the back of "TV and Other Receiving Antennas" by Arnold Bailey is an interesting section which describes a large number of commonly-used TV antenna configurations - dipoles made of wire and rod, folded dipoles with various wire diameters and spacings, bot-tie, simple Yagi, and so forth. For each such, Bailey gives two impedance figures - the "surge" impedance and the feedpoint impedance - which I believe correspond to the two impedances Cecil is referring to (i.e. before, and after the standing wave is established). It's an interesting book... out of print for years, and not (as far as I know) available electronically. -- Dave Platt AE6EO Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior I do _not_ wish to receive unsolicited commercial email, and I will boycott any company which has the gall to send me such ads! How many pages does that book of Bailey's have? How much would it cost to put on the internet for all hams to enjoy? |
skin depth decay
On 20 Nov, 16:02, (Richard Harrison) wrote:
I wrote: "The impressed current will lag the voltage across a pure inductance by 90 degrees." Roy wrote: "For other waveforms (like the ones you`d get connecting batteries or capacitors) you have to resort to the more general time relationship L*di/dt. Roy is correct for connecting batteries or capacitors but Art was working wih a lengthy antenna, not a lone elementary segment. He also had no step functions, just a sine wave driving his antenna. Best regards, Richard Harrison, KB5WZI I am afraid it is more than that. Without an understanding of changing phase angles of both voltage and current you will never understand antennas. Look back at the comment you made with respect to phase angle and then re read Roy's comment where he corrected you with respect to phase angles. You will just have to refresh yourself with respect to voltage and current phase angles especially when they have the SAME phase angle . My guess is you will find it in books by Bailey, Kraus and ofcourse "you know who". And yes, I feed my antenna with a sine wave which by passes a capacitor but what on earth has that got to do with the subject of batteries e.t.c.? That sino soidal bypass is often termed "leakage" which is extremely small compared to the total energy fed to a radiator that creats radiation tho necessary for relative phase angles to change. You made a reference to" 101" for those who went to college well if you did,then refresh yourself with notes taken Art Unwin |
skin depth decay
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skin depth decay
Richard Clark wrote:
On Tue, 20 Nov 2007 16:23:45 -0800, (Dave Platt) wrote: Bailey gives two impedance figures - the "surge" impedance and the feedpoint impedance Re pg 340: "By definition, the surge impedance of a conductor for all practical purposes is that value of load resistance which, if placed at the end of the conductor, will completely prevent refelcted power from being sent back into the conductor by the load." Less conductor periphery, more surge Z. Some representative values: Thin dipole 610 Ohms (Thin = #10 wire @ 200MC) Dipole 420 Ohms (0.5" @ 200MC) Thick Dipole 240 Ohms (Thick = 2.5" @ 200MC) Vertical 260 Ohms (.25" @ 200MC) Biconical 150 Ohms YMMV Ok, I give up. I've got a dipole in free space. I connect one end of the load resistance to one end of the dipole. What do I connect the other end of the resistor to? If that's too tough, how about just a dipole a quarter wavelength above ground? Roy Lewallen, W7EL |
skin depth decay
Art wrote:
"Oh Richard, you may deny my antenna but that is what I was alluding to. Again it is the LC ratio that must be kept for resonance." I don`t know enough about Art`s antenna to deny it. I do know that resonance depends on the reciprocal of the sq. rt. of the product of LC, not its quotient. Explosive results from an inductor were introduced by Kettering, I believe, through interruption of battery current through an inductor to generate a very high voltage spark to ignite the fuel air mixture within the cylinder of an internal combustion engine for automobiles. Just as I doubt the inclusion of a pendulum in Art`s antenna, I also doubt the presence of an interruptor to discharge either the capacitance or inductance in the resonant antenna. If Art`s antenna is novel, useful, and not completely obvious from prior knowlege, he may profit from it. I wish him all the best. Best regards, Richard Harrison, KB5WZI |
skin depth decay
Art wrote:
"How many pages soes that book of Bailey`s have?" 595 and each one is valuable. Best regards, Richard Harrison, KB5WZI |
skin depth decay
Dave Platt wrote:
In the back of "TV and Other Receiving Antennas" by Arnold Bailey is an interesting section which describes a large number of commonly-used TV antenna configurations - dipoles made of wire and rod, folded dipoles with various wire diameters and spacings, bot-tie, simple Yagi, and so forth. Yes, an antenna has a surge impedance just like a transmission line has a surge impedance which is the characteristic impedance. A standing wave antenna and a transmission line with standing waves both exhibit virtual feedpoint impedances that differ from the characteristic impedances. -- 73, Cecil http://www.w5dxp.com |
skin depth decay
Roy Lewallen wrote:
Ok, I give up. I've got a dipole in free space. I connect one end of the load resistance to one end of the dipole. What do I connect the other end of the resistor to? How about a nice terminated rhombic? If that's too tough, how about just a dipole a quarter wavelength above ground? How about an inv-V dipole 0.177 wavelength above ground? -- 73, Cecil http://www.w5dxp.com |
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