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Antenna physical size
I have searched quite a bit for evidence that states that performance
of antennas can be rated by it's size. Formulas do not refere to radiator size or volume and aparture is referenced to gain. I understand that sort of thinking based on Yagi design but the idea that all small radiators are inefficient is rather ludicrouse. My work, based on the sciences of the masters, show that a efficient radiator can be any size,shape and configuration as long as it is in equilibrium . Period No where can I find reference to "size" in what the masters state Regards Art |
Antenna physical size
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Antenna physical size
Art wrote:
"No where can I find reference to "size" in what the masters state" More diligence! Terman never failed to have an answer for me. On page 864 of his 1955 0pus he writes: "The simplest wire radiator or antenna is the elementary doublet shown in Fig. 23-1a. This consists of a conductor of length small-delta l that is short compared with the wavelength lambda, and which is assumed to have such large capacitance areas associated with each end that current flowing throughout the length of the doublet everywhere has the same value I. The strength E of the field radiated from such an elementary antenna in volts per unit length by a current I cos (omega t + 90 degrees) is given by the formula E = 60 pi/d l/lambda Icos theta cos omega (t-d/c) Eqn. (23-1) Here d is the distance from the doublet to a distant receiving point P, and theta is the direction of P with respect a plane perpendicular to the axis of the doublet while c is the velocity of light. The strength of the radiated field is distributed in space in accordance with the doughnut pattern with a figure-of-eight cross section shown in Fig. 23-1b." The above is only the beginning of Terman`s chapter on antennas. Fig. 23-2 shows how contributions from multiple doublets in a larger antenna combine to produce the pattern of the larger antenna. Point to be noted is that length over lambda is a multiplier in Eqn.(23-1). Obviously size (length) does make a difference. Best regards, Richard Harrison, KB5WZI |
Antenna physical size
On Mar 7, 2:08 pm, (Richard Harrison) wrote:
Art wrote: "No where can I find reference to "size" in what the masters state" More diligence! Terman never failed to have an answer for me. On page 864 of his 19550pus he writes: "The simplest wire radiator or antenna is the elementary doublet shown in Fig. 23-1a. This consists of a conductor of length small-delta l that is short compared with the wavelength lambda, and which is assumed to have such large capacitance areas associated with each end that current flowing throughout the length of the doublet everywhere has the same value I. The strength E of the field radiated from such an elementary antenna in volts per unit length by a current I cos (omega t + 90 degrees) is given by the formula E = 60 pi/d l/lambda Icos theta cos omega (t-d/c) Eqn. (23-1) Here d is the distance from the doublet to a distant receiving point P, and theta is the direction of P with respect a plane perpendicular to the axis of the doublet while c is the velocity of light. The strength of the radiated field is distributed in space in accordance with the doughnut pattern with a figure-of-eight cross section shown in Fig. 23-1b." The above is only the beginning of Terman`s chapter on antennas. Fig. 23-2 shows how contributions from multiple doublets in a larger antenna combine to produce the pattern of the larger antenna. Point to be noted is that length over lambda is a multiplier in Eqn.(23-1). Obviously size (length) does make a difference. Best regards, Richard Harrison, KB5WZI I disagree. Laws written are all based on the assumption of equilibrium and that includes Maxwell's laws. These laws hav e zero refernce to size as such though many would seek for the word volume. Pertinent factors are wave length of frequency in use and root LC. For equilibrium there is zero reference to size or volume. I ofcourse fall back to the term equilibrium which is a basic for Gauss's law of statics to which a variable time can be added. Thus it can be seen that a law can be stated that a radiator can be any size, shape or configuration as long as it is in equilibrium. The problem here is that amateur radio is wellded to the yagi design which is not one of equilibrium and the fact that amateurs and many of the higher educated have pushed the term of equilibrium outside the box. This shows up when the uneducated refer to small antennas as being inefficient based purely on the connection to a specific design without regard to whether equilibrium exists so that all the laws of the masters can be applied. Again, it is implicite that all laws apply when there is equilibrium, if there is not then the laws do not apply as is. With respect to the term "length", this is not synonimous to "size" because it has only one degree of freedom. There is no reason why a radiator can be rolled up into any shape as long as the laws of Maxwell are adhered to and such a sample has been assigned for testing and I have to be satisfied with the results as they arrive.I will be soon using one on the radio for QSO's and I apologise if its use offends anybody Seems like the group is in quite a tizzy that a person would have a small radiator that defies that which has taken them years to memorize. I gave all pertinent details how to make them I also gave the mathematics and a sample where established computor programs confirm the above and now to upset all again I have given a sample for testing to a independent reviewer. There is no need for anybody to worry, Yagi designs still exist for those who abore change,worry about transmission line radiation or even radiators melting. When you all understand the relevence of equilibrium you can then procede to review the math, until then you are all in left field. Best regards Art There is nothing in Maxwells laws that prohibit a "wavelength" from being condensed into the size of a pinhead or smaller and still be "efficient" with respect to stated paramitors. |
Antenna physical size
"Art Unwin" wrote in message ... On Mar 7, 2:08 pm, (Richard Harrison) wrote: I disagree. Laws written are all based on the assumption of equilibrium and that includes Maxwell's laws. These laws hav e zero refernce to size as such though many would seek because contrary to what those male enhancement product adds tell you, size doesn't matter. for the word volume. Pertinent factors are wave length of frequency in The problem here is that amateur radio is wellded to the yagi design which is not one of equilibrium WAIT JUST ONE GOSH DARN MINUTE! you have said in the past that the simple half wave dipole WAS a prefect example of equilibrium! NOW it isn't??? have you had a new revelation while i had your old email address plonked?? |
Antenna physical size
On Mar 7, 4:45 pm, "Dave" wrote:
"Art Unwin" wrote in message ... On Mar 7, 2:08 pm, (Richard Harrison) wrote: I disagree. Laws written are all based on the assumption of equilibrium and that includes Maxwell's laws. These laws hav e zero refernce to size as such though many would seek because contrary to what those male enhancement product adds tell you, size doesn't matter. for the word volume. Pertinent factors are wave length of frequency in The problem here is that amateur radio is wellded to the yagi design which is not one of equilibrium WAIT JUST ONE GOSH DARN MINUTE! you have said in the past that the simple half wave dipole WAS a prefect example of equilibrium! NOW it isn't??? have you had a new revelation while i had your old email address plonked?? David, You admit to not understanding the term "equilibrium" so what do you care what I say and in what content. If you consider a half wave dipole as being in equilibrium you have to consider the electrical circuit consisting of a capacitance from the antenna to ground or the route thru the center of of the radiator, both of thes circuits can be considered as being in equilibrium. However, on this newsgroup a fractional wavelength radiator is considered as an open circuit for some reason and thus under those circumstances the half wave dipole is not in equilibrium. Now your views on radiation is all over the place so it is very hard for me to determine the context of what you say. Art |
Antenna physical size
Art wrote:
"I sisagree." Most correspondents here know from experience that radiation efficacy falls in too-short antennas.Terman refers to E.A. Laport`s "Radio Antenna Engineering". Laport has charted Degree-amperes versus Field Strength or radiation resistance to which Field Strength is proportional. Laport gives an example on page 23: "A straight vertical radiator of height 30 degrees or less has a radiation resistance Rr following the equation Rr = Go squared. where Go is the electrical height in radians (One radian is 57.3 degrees.) Best regards, Richard Harrison, KB5WZI |
Antenna physical size
"Art Unwin" wrote in message ... On Mar 7, 4:45 pm, "Dave" wrote: "Art Unwin" wrote in message ... On Mar 7, 2:08 pm, (Richard Harrison) wrote: I disagree. Laws written are all based on the assumption of equilibrium and that includes Maxwell's laws. These laws hav e zero refernce to size as such though many would seek because contrary to what those male enhancement product adds tell you, size doesn't matter. for the word volume. Pertinent factors are wave length of frequency in The problem here is that amateur radio is wellded to the yagi design which is not one of equilibrium WAIT JUST ONE GOSH DARN MINUTE! you have said in the past that the simple half wave dipole WAS a prefect example of equilibrium! NOW it isn't??? have you had a new revelation while i had your old email address plonked?? David, You admit to not understanding the term "equilibrium" so what do you care what I say and in what content. If you consider a half wave dipole as being in equilibrium you have to no, it wasn't me that said that, you said that a half wave dipole was an example of your equilibrium gaussian antenna. don't put words in my mouth, i don't think any antenna is in 'equilibrium' if it is working right, there is always a flow of power either in or out... equilibrium means not going anywhere, i want my antennas to radiate and receive, not just sit there and look pretty! |
Antenna physical size
On Mar 7, 6:02 pm, "Dave" wrote:
"Art Unwin" wrote in message ... On Mar 7, 4:45 pm, "Dave" wrote: "Art Unwin" wrote in message ... On Mar 7, 2:08 pm, (Richard Harrison) wrote: I disagree. Laws written are all based on the assumption of equilibrium and that includes Maxwell's laws. These laws hav e zero refernce to size as such though many would seek because contrary to what those male enhancement product adds tell you, size doesn't matter. for the word volume. Pertinent factors are wave length of frequency in The problem here is that amateur radio is wellded to the yagi design which is not one of equilibrium WAIT JUST ONE GOSH DARN MINUTE! you have said in the past that the simple half wave dipole WAS a prefect example of equilibrium! NOW it isn't??? have you had a new revelation while i had your old email address plonked?? David, You admit to not understanding the term "equilibrium" so what do you care what I say and in what content. If you consider a half wave dipole as being in equilibrium you have to no, it wasn't me that said that, you said that a half wave dipole was an example of your equilibrium gaussian antenna. don't put words in my mouth, i don't think any antenna is in 'equilibrium' if it is working right, there is always a flow of power either in or out... equilibrium means not going anywhere, i want my antennas to radiate and receive, not just sit there and look pretty! David, please plonk me again under my new server. Thanks Art |
Antenna physical size
On Mar 7, 6:09 pm, Art Unwin wrote:
On Mar 7, 4:45 pm, "Dave" wrote: "Art Unwin" wrote in message ... On Mar 7, 2:08 pm, (Richard Harrison) wrote: I disagree. Laws written are all based on the assumption of equilibrium and that includes Maxwell's laws. These laws hav e zero refernce to size as such though many would seek because contrary to what those male enhancement product adds tell you, size doesn't matter. for the word volume. Pertinent factors are wave length of frequency in The problem here is that amateur radio is wellded to the yagi design which is not one of equilibrium WAIT JUST ONE GOSH DARN MINUTE! you have said in the past that the simple half wave dipole WAS a prefect example of equilibrium! NOW it isn't??? have you had a new revelation while i had your old email address plonked?? David, You admit to not understanding the term "equilibrium" so what do you care what I say and in what content. If you consider a half wave dipole as being in equilibrium you have to consider the electrical circuit consisting of a capacitance from the antenna to ground or the route thru the center of of the radiator, both of thes circuits can be considered as being in equilibrium. However, on this newsgroup a fractional wavelength radiator is considered as an open circuit for some reason and thus under those circumstances the half wave dipole is not in equilibrium. Now your views on radiation is all over the place so it is very hard for me to determine the context of what you say. Art Long before we rode our dinosaurs to club meetings the bright lights had completely agreed that the strength of radio signals at far off places was a function of the integral of i·dl where dl is the bigness of the aerial. Maybe it's in Sears and Zemansky. I dunno . . nor do I really care. w3rv |
Antenna physical size
On Mar 7, 6:13 pm, Brian Kelly wrote:
On Mar 7, 6:09 pm, Art Unwin wrote: On Mar 7, 4:45 pm, "Dave" wrote: "Art Unwin" wrote in message .... On Mar 7, 2:08 pm, (Richard Harrison) wrote: I disagree. Laws written are all based on the assumption of equilibrium and that includes Maxwell's laws. These laws hav e zero refernce to size as such though many would seek because contrary to what those male enhancement product adds tell you, size doesn't matter. for the word volume. Pertinent factors are wave length of frequency in The problem here is that amateur radio is wellded to the yagi design which is not one of equilibrium WAIT JUST ONE GOSH DARN MINUTE! you have said in the past that the simple half wave dipole WAS a prefect example of equilibrium! NOW it isn't??? have you had a new revelation while i had your old email address plonked?? David, You admit to not understanding the term "equilibrium" so what do you care what I say and in what content. If you consider a half wave dipole as being in equilibrium you have to consider the electrical circuit consisting of a capacitance from the antenna to ground or the route thru the center of of the radiator, both of thes circuits can be considered as being in equilibrium. However, on this newsgroup a fractional wavelength radiator is considered as an open circuit for some reason and thus under those circumstances the half wave dipole is not in equilibrium. Now your views on radiation is all over the place so it is very hard for me to determine the context of what you say. Art Long before we rode our dinosaurs to club meetings the bright lights had completely agreed that the strength of radio signals at far off places was a function of the integral of i·dl where dl is the bigness of the aerial. Maybe it's in Sears and Zemansky. I dunno . . nor do I really care. w3rv Nothing wrong with that with respect to yagis it just doesn't refer to all antennas |
Antenna physical size
On Mar 7, 11:46 am, Jim Lux wrote:
wrote: I have searched quite a bit for evidence that states that performance of antennas can be rated by it's size. Formulas do not refere to radiator size or volume and aparture is referenced to gain. I understand that sort of thinking based on Yagi design but the idea that all small radiators are inefficient is rather ludicrouse. My work, based on the sciences of the masters, show that a efficient radiator can be any size,shape and configuration as long as it is in equilibrium . Period No where can I find reference to "size" in what the masters state Regards Art The work by Chu (Journal of Applied Physics, p1163, v19, Dec 1948) and subsequently by Harrington (IEEE Trans Ant & Prop, V18#6, Nov 1965, p896) , Thiele (IEEE Trans on Ant and Prop, v51, #6, June 2003, p1263) and later others, discusses fundamental limits on performance. Watch out, though, for the assumptions in the constraints (e.g. whether the device attached to the feedpoint is reciprocal), and, of course, where the boundary of the system is. Watch out also for the definition of "Q", which in this context is the ratio of stored to disspated/radiated energy, not the ratio of center frequency/bandwidth. In short, there is a tradeoff between Q, directivity, and size. And, because high Q implies high stored energy, for physically realizable antennas with loss, efficiency is in the mix too. Googling "chu harrington limit" often turns up useful stuff. Googled Chu harrington and find that his work is basically empirical around known arrangements. When he brought the question of Q into the picture he made the statement that small antennas are usually of a low impedance which is correct empirically with respect to existing designs but it is not exclusive when dealing with all radiators that can be made that comply with Maxwells laws. As I have said before it is implicite in Maxwells laws that a efficient radiator can be any size shape or configuration as long as it complies with Maxwells law. In my case my small antenna can have any impedance value for equilibrium and it is quite easy to have a resistive impedance in the hundreds of ohms as well as minuit impedances. I conform to 50 ohms purely because of component availability. As another aside my small antennas have a much wider bandwidth than any other available! As far as gain or energy transmitted that all depends on what frequencies get thru the bandpass filter and in no way directs out of pass energy to be be redirected to band pass status and augment energy transmitted. Stored energy has no relationship to Q in my mind since it goes around or circulates as with a tank circuit energy that lies within the pass bandof the tank circuit filter. To summate, my antenna design is considered small yet complies with Maxwells laws and yet does not have a narrow bandwidth or low impedance thus Chu's comments cannot be inclusive of all radiators. Best regards Art |
Antenna physical size
On Mar 7, 5:54 pm, (Richard Harrison) wrote:
Art wrote: "I sisagree." Most correspondents here know from experience that radiation efficacy falls in too-short antennas.Terman refers to E.A. Laport`s "Radio Antenna Engineering". Laport has charted Degree-amperes versus Field Strength or radiation resistance to which Field Strength is proportional. Laport gives an example on page 23: "A straight vertical radiator of height 30 degrees or less has a radiation resistance Rr following the equation Rr = Go squared. where Go is the electrical height in radians (One radian is 57.3 degrees.) Best regards, Richard Harrison, KB5WZI Note. that applies to a particular straight antenna and not to all radiators as a whole. Maxwell does not state that a radiator must be straight or any particular shape for his law to be applicable. Art |
Antenna physical size
On Mar 7, 7:29 pm, Art Unwin wrote:
When he brought the question of Q into the picture he made the statement that small antennas are usually of a low impedance which is correct empirically with respect to existing designs but it is not exclusive when dealing with all radiators that can be made that comply with Maxwells laws. I take it your version is gifted and suffers not from a low Q... :/ As I have said before it is implicite in Maxwells laws that a efficient radiator can be any size shape or configuration as long as it complies with Maxwells law. Sure it can. Common knowledge. It's also common knowledge that the trick with building a small efficient antenna is not really the size of the radiator itself, it's actually getting power to that small radiator. In my case my small antenna can have any impedance value for equilibrium and it is quite easy to have a resistive impedance in the hundreds of ohms as well as minuit impedances. I conform to 50 ohms purely because of component availability. As another aside my small antennas have a much wider bandwidth than any other available! As previously noted, you have reinvented the air cooled dummy load. Your performance specs sure seem to mimic one anyway.. :/ As far as gain or energy transmitted that all depends on what frequencies get thru the bandpass filter and in no way directs out of pass energy to be be redirected to band pass status and augment energy transmitted. Stored energy has no relationship to Q in my mind since it goes around or circulates as with a tank circuit energy that lies within the pass bandof the tank circuit filter. To summate, my antenna design is considered small yet complies with Maxwells laws and yet does not have a narrow bandwidth or low impedance thus Chu's comments cannot be inclusive of all radiators. Best regards Art As far as the rest, my cat has mittens.. :/ BTW, you need to define "equilibrium". After several months you still are lagging at this task. MK |
Antenna physical size
On Mar 7, 5:09 pm, Art Unwin wrote:
David, You admit to not understanding the term "equilibrium" so what do you care what I say and in what content. I don't think anyone here really knows how you define that word as it pertains to your antenna design. Once I saw where you said it meant the antenna was resonant, "eham?" but that seems to change with the direction of the wind and the amount of snowfall on the ground. MK |
Antenna physical size
On Mar 7, 8:32 pm, wrote:
On Mar 7, 5:09 pm, Art Unwin wrote: David, You admit to not understanding the term "equilibrium" so what do you care what I say and in what content. I don't think anyone here really knows how you define that word as it pertains to your antenna design. Once I saw where you said it meant the antenna was resonant, "eham?" but that seems to change with the direction of the wind and the amount of snowfall on the ground. MK What is your real p;roblem? You have not seen my antenna and obviously dont understand the mathematics and you are not an engineer, Yet you have made so many comments and opinions that berate the design and seem un willing to wait until the independent review comes in. On top of that you want help with the word equilibrium!. Give me a break.You should have pursued an education instead of bragging how often you quit going to school then you would not appear so ignorant about antennas. Treat it as a hobby and forget about the being an expert side of things, for you it is to late. And yes the antenna is resonant but rezonance does not always equate to equilibrium. With respect to feeding a small antenna it is not that difficult especially if you choose a resonance of 50 ohm resistive. With respect to your world beating antenna that is so easy when you get rid of those loading antics that you use. I know you can work all you can hear but what about all that your inefficient antenna is n0lt hearing? Art |
Antenna physical size
On Mar 7, 9:36 pm, Art Unwin wrote:
On Mar 7, 8:32 pm, wrote: On Mar 7, 5:09 pm, Art Unwin wrote: David, You admit to not understanding the term "equilibrium" so what do you care what I say and in what content. I don't think anyone here really knows how you define that word as it pertains to your antenna design. Once I saw where you said it meant the antenna was resonant, "eham?" but that seems to change with the direction of the wind and the amount of snowfall on the ground. MK What is your real p;roblem? You have not seen my antenna and obviously dont understand the mathematics and you are not an engineer, Yet you have made so many comments and opinions that berate the design and seem un willing to wait until the independent review comes in. On top of that you want help with the word equilibrium!. Give me a break.You should have pursued an education instead of bragging how often you quit going to school then you would not appear so ignorant about antennas. Treat it as a hobby and forget about the being an expert side of things, for you it is to late. And yes the antenna is resonant but rezonance does not always equate to equilibrium. With respect to feeding a small antenna it is not that difficult especially if you choose a resonance of 50 ohm resistive. With respect to your world beating antenna that is so easy when you get rid of those loading antics that you use. I know you can work all you can hear but what about all that your inefficient antenna is n0lt hearing? Art |
Antenna physical size
Art wrote:
"No where can I find reference to "size" in what the masters state." It`s there if you look. Kraus is a certified master. In the newest edition, the 3rd, of "Antennas" is found on page 12: "The basic equation of radiation may be expressed simply as IL=QV, where I=time changing current L=length of current element Q=charge,C V=time change of velocity or acceleration Thus, time changing current radiates and accelerated charge radiates. For steady-state harmonic radiation, we usually focus on current. For transients or pulses, we focus on charge." The above is the beginning of the chapter on "Antenna Basics". Everyone interested in antennas needs ready access to this important book. Best regards, Richard Harrison, KB5WZI |
Antenna physical size
"Brian Kelly" wrote in message ... On Mar 7, 6:09 pm, Art Unwin wrote: On Mar 7, 4:45 pm, "Dave" wrote: "Art Unwin" wrote in message ... On Mar 7, 2:08 pm, (Richard Harrison) wrote: I disagree. Laws written are all based on the assumption of equilibrium and that includes Maxwell's laws. These laws hav e zero refernce to size as such though many would seek because contrary to what those male enhancement product adds tell you, size doesn't matter. for the word volume. Pertinent factors are wave length of frequency in The problem here is that amateur radio is wellded to the yagi design which is not one of equilibrium WAIT JUST ONE GOSH DARN MINUTE! you have said in the past that the simple half wave dipole WAS a prefect example of equilibrium! NOW it isn't??? have you had a new revelation while i had your old email address plonked?? David, You admit to not understanding the term "equilibrium" so what do you care what I say and in what content. If you consider a half wave dipole as being in equilibrium you have to consider the electrical circuit consisting of a capacitance from the antenna to ground or the route thru the center of of the radiator, both of thes circuits can be considered as being in equilibrium. However, on this newsgroup a fractional wavelength radiator is considered as an open circuit for some reason and thus under those circumstances the half wave dipole is not in equilibrium. Now your views on radiation is all over the place so it is very hard for me to determine the context of what you say. Art Long before we rode our dinosaurs to club meetings the bright lights had completely agreed that the strength of radio signals at far off places was a function of the integral of i·dl where dl is the bigness of the aerial. Maybe it's in Sears and Zemansky. I dunno . . nor do I really care. w3rv Antennas for All Applications, 3rd Edition, Kraus & Marhefka, McGraw-Hill, page 12. Begin quote Regardless of antenna type, all involve the same basic principle that radiation is produced by accelerated (or decelerated) charge. The basic equation of radiation may be expressed simply as IL = Qv (A m / s) where I = time-changing current, A/s L = length of current element, m Q = charge, C v = time change of velocity which equals the acceleration of the charge, m/s Thus, time-changing current radiates and accelerated charge radiates. For steady-state harmonic variation, we usually focus on current. For transients or pulses, we focus on charge. The radiation is perpendicular to the acceleration, and the radiated power is proportional to the square of IL or Qv. end quote Cheers, John |
Antenna physical size
On Mar 7, 9:36 pm, Art Unwin wrote:
On Mar 7, 8:32 pm, wrote: On Mar 7, 5:09 pm, Art Unwin wrote: David, You admit to not understanding the term "equilibrium" so what do you care what I say and in what content. I don't think anyone here really knows how you define that word as it pertains to your antenna design. Once I saw where you said it meant the antenna was resonant, "eham?" but that seems to change with the direction of the wind and the amount of snowfall on the ground. MK What is your real p;roblem? Dunno..The price of motor fuel? Ammunition prices keep going up? My butt itches? I dunno.. I'll ponder this further and get back to you. You have not seen my antenna and obviously dont understand the mathematics and you are not an engineer, Yet you have made so many comments and opinions that berate the design and seem un willing to wait until the independent review comes in. What mathematics? You haven't given any. Not a bit that I recall. You only talk about winding loads of thin 22 gauge wire onto a form about the size of a shoe box or two, and and mutter something about a garbage can lid, and that freaking "E" word over and over.. I guess I missed all the math you providing on this marvel of engineering. Who said I can't wait? I'm in no hurry. Take all the time you want. If you can turn a turd into a diamond, I'll be the first to applaud. I'm not going to hold my breath though.. On top of that you want help with the word equilibrium!. I'm well aware of how most normal people define the word. I want to know how you define it. You use it in nearly every post, but you seem to refuse to define how it applies to an antenna system. Give me a break.You should have pursued an education instead of bragging how often you quit going to school then you would not appear so ignorant about antennas. Art, you kill me. At least I have an excuse... What is yours? Treat it as a hobby and forget about the being an expert side of things, for you it is to late. I don't need to be an expert to smell a turd. How come an self proclaimed expert like you can't smell one? And yes the antenna is resonant but rezonance does not always equate to equilibrium. Well, does it always equate to? This may or may not be a trick question... This is a fine example of the silly crap you pull that compels me to tweak your differential every once in a while. You can't answer a straight question without using some form of bafflegab to try to confuse the questioner, or to imply that he/she must surely be brain dead to even ask the question in the first place. With respect to feeding a small antenna it is not that difficult especially if you choose a resonance of 50 ohm resistive. How are you going to choose this value when the 160m antenna is the size of a shoebox? Seems to me you are going to get what you get, and then have to match to it. If your design is that small and requires no matching... Oh, forget it... Art, you are killing me with your voodoo logic.. I succumb.. With respect to your world beating antenna that is so easy when you get rid of those loading antics that you use. What in the world are you babbling about now? Which one of antennas are you referring to? None of my antennas require loading "antics" except my mobile whips. All my others are manly full size antennas which require no loading antics, equilibrium, or quivers in the force to function properly. I know you can work all you can hear but what about all that your inefficient antenna is n0lt hearing? Art How would you know what I can work? You don't ever get on the air. How do you know I even get on the air? I might just leave it on all day and do nothing but look at the lights and blinky things for all you know. Also, I hate to break it to a whiney horses ass like you, but none of my home antennas are inefficient. Not a one. And I'd wager my mobile antenna is more efficient than your shoe box sized 160m device. I'm curious... Being you are so educated, how come a dumbass uneducated hick like me has a bit better writing skills than you? And English was probably my least liked subject to boot... I slept through most all of those classes as I recall. Yet you spell resonance as rezonance. You almost make me feel gifted in some way. :/ MK |
Antenna physical size
On Mar 7, 9:36 pm, Art Unwin wrote:
On Mar 7, 8:32 pm, wrote: On Mar 7, 5:09 pm, Art Unwin wrote: David, You admit to not understanding the term "equilibrium" so what do you care what I say and in what content. I don't think anyone here really knows how you define that word as it pertains to your antenna design. Once I saw where you said it meant the antenna was resonant, "eham?" but that seems to change with the direction of the wind and the amount of snowfall on the ground. MK What is your real p;roblem? You have not seen my antenna and obviously dont understand the mathematics and you are not an engineer, Yet you have made so many comments and opinions that berate the design and seem un willing to wait until the independent review comes in. On top of that you want help with the word equilibrium!. Give me a break.You should have pursued an education instead of bragging how often you quit going to school then you would not appear so ignorant about antennas. Treat it as a hobby and forget about the being an expert side of things, for you it is to late. And yes the antenna is resonant but rezonance does not always equate to equilibrium. With respect to feeding a small antenna it is not that difficult especially if you choose a resonance of 50 ohm resistive. With respect to your world beating antenna that is so easy when you get rid of those loading antics that you use. I know you can work all you can hear but what about all that your inefficient antenna is n0lt hearing? Art Tell you what... Instead of tweaking you further, I'll just sit back and watch the show. Take all the time you want. I have enough confidence in known "living in the past" theory to see that what you are trying to achieve, "full size performance and efficiency from a very small radiator" is not going to pan out how you expect it to. Good luck in the contest. But when you are ready to divulge the reports of the comparision and tests, don't be overly offended when people ask pertinent questions about possible feedline radiation and other sorts of RF augmentation, intentional, or not. Evasion of these questions will invoke my tweaking reflex, which could get ugly to passersby. :/ MK |
Antenna physical size
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Antenna physical size
"Art Unwin" wrote in message ... On Mar 7, 6:02 pm, "Dave" wrote: "Art Unwin" wrote in message ... On Mar 7, 4:45 pm, "Dave" wrote: "Art Unwin" wrote in message ... On Mar 7, 2:08 pm, (Richard Harrison) wrote: I disagree. Laws written are all based on the assumption of equilibrium and that includes Maxwell's laws. These laws hav e zero refernce to size as such though many would seek because contrary to what those male enhancement product adds tell you, size doesn't matter. for the word volume. Pertinent factors are wave length of frequency in The problem here is that amateur radio is wellded to the yagi design which is not one of equilibrium WAIT JUST ONE GOSH DARN MINUTE! you have said in the past that the simple half wave dipole WAS a prefect example of equilibrium! NOW it isn't??? have you had a new revelation while i had your old email address plonked?? David, You admit to not understanding the term "equilibrium" so what do you care what I say and in what content. If you consider a half wave dipole as being in equilibrium you have to no, it wasn't me that said that, you said that a half wave dipole was an example of your equilibrium gaussian antenna. don't put words in my mouth, i don't think any antenna is in 'equilibrium' if it is working right, there is always a flow of power either in or out... equilibrium means not going anywhere, i want my antennas to radiate and receive, not just sit there and look pretty! David, please plonk me again under my new server. Thanks Art why, you don't like someone to point out inconsistencies in your rantings? i'll probably keep you un-plonked for a bit, wx is bad this weekend, no big contests, and tx5c hasn't landed yet to listen to that zoo, so i could use some entertainment. |
Antenna physical size
On Mar 7, 11:19 pm, (Richard Harrison)
wrote: Art wrote: "No where can I find reference to "size" in what the masters state." It`s there if you look. Kraus is a certified master. In the newest edition, the 3rd, of "Antennas" is found on page 12: "The basic equation of radiation may be expressed simply as IL=QV, where I=time changing current L=length of current element Q=charge,C V=time change of velocity or acceleration Thus, time changing current radiates and accelerated charge radiates. For steady-state harmonic radiation, we usually focus on current. For transients or pulses, we focus on charge." The above is the beginning of the chapter on "Antenna Basics". Everyone interested in antennas needs ready access to this important book. Best regards, Richard Harrison, KB5WZI But you arer forgettfull Richard, my antenna is a full wavelength which meets Maxwells requirements, it is just that the volume is small despite the wavelength. It is also not in conflict with "antenna basics" alluded to above. I don't understandwhat the beef is. Why are so many hams alarmed at the idea? Regards Art |
Antenna physical size
"Art Unwin" wrote in message ... On Mar 7, 11:19 pm, (Richard Harrison) wrote: Art wrote: "No where can I find reference to "size" in what the masters state." It`s there if you look. Kraus is a certified master. In the newest edition, the 3rd, of "Antennas" is found on page 12: "The basic equation of radiation may be expressed simply as IL=QV, where I=time changing current L=length of current element Q=charge,C V=time change of velocity or acceleration Thus, time changing current radiates and accelerated charge radiates. For steady-state harmonic radiation, we usually focus on current. For transients or pulses, we focus on charge." The above is the beginning of the chapter on "Antenna Basics". Everyone interested in antennas needs ready access to this important book. Best regards, Richard Harrison, KB5WZI But you arer forgettfull Richard, my antenna is a full wavelength which meets Maxwells requirements, it is just that the volume is small despite the wavelength. It is also not in conflict with "antenna basics" alluded to above. I don't understandwhat the beef is. Why are so many hams alarmed at the idea? Regards Art its called 'experience' by most and 'knowledge' by those in the know. |
Antenna physical size
Art wrote:
"---my antenna is a full wavelength which meets Maxwell`s requirements, it is just that the volume is small despite the wavelength." In 1949, I worked at the KPRC-KXYZ broadcast plant. Another operator there, J.L. Davis, W5LIT had a new 1949 Ford in which he installed a surplus ART-13 and a PE-103 dynamotor. For an antenna he wound wire turn by turn on a bamboo pole until it was resonant on a slice of the 75-meter band. When J.L. modulated, Q in the coil produced a tip corona on the first good peak and modulation became loud without a receiver. The 20th edition of the ARRL Antenna Book on page 16-13 says this about continuously loaded antennas: "The general approach has been to use a coil made from heavy wire (#14 or larger), with length-to-diameter ratios as high as 21. British experimeters have reported good results with 8-foot overall length on the 1.8- and 3.5 MHz bands. The idea of making the entire antenna out of one section of coil has been tried with some success." Art`s antenna containing a "full wavelength" of wire would likely feature a greater loss than J.L.`s 1/4-wave resonant coil from simply a greater length of wire while both have peactances balanced to zero. Art`s lower Q would probably kill the corona, increase the bandwidth, while losing the gain that a fullwave straight conductor enjoys. Cecil can probably report on results of continuously loaded mobile antennas versus a bug catcher loaded whip in the California shoot-outs. Best regards, Richard Harrison, KB5WZI |
Antenna physical size
On Mar 8, 10:21 am, (Richard Harrison)
wrote: Art wrote: "---my antenna is a full wavelength which meets Maxwell`s requirements, it is just that the volume is small despite the wavelength." In 1949, I worked at the KPRC-KXYZ broadcast plant. Another operator there, J.L. Davis, W5LIT had a new 1949 Ford in which he installed a surplus ART-13 and a PE-103 dynamotor. For an antenna he wound wire turn by turn on a bamboo pole until it was resonant on a slice of the 75-meter band. When J.L. modulated, Q in the coil produced a tip corona on the first good peak and modulation became loud without a receiver. The 20th edition of the ARRL Antenna Book on page 16-13 says this about continuously loaded antennas: "The general approach has been to use a coil made from heavy wire (#14 or larger), with length-to-diameter ratios as high as 21. British experimeters have reported good results with 8-foot overall length on the 1.8- and 3.5 MHz bands. The idea of making the entire antenna out of one section of coil has been tried with some success." Art`s antenna containing a "full wavelength" of wire would likely feature a greater loss than J.L.`s 1/4-wave resonant coil from simply a greater length of wire while both have peactances balanced to zero. Art`s lower Q would probably kill the corona, increase the bandwidth, while losing the gain that a fullwave straight conductor enjoys. Cecil can probably report on results of continuously loaded mobile antennas versus a bug catcher loaded whip in the California shoot-outs. Best regards, Richard Harrison, KB5WZI There are no loads on my antenna so your statements are irrelavent Art |
Antenna physical size
"Art Unwin" wrote in message ... On Mar 8, 10:21 am, (Richard Harrison) wrote: Art wrote: "---my antenna is a full wavelength which meets Maxwell`s requirements, it is just that the volume is small despite the wavelength." In 1949, I worked at the KPRC-KXYZ broadcast plant. Another operator there, J.L. Davis, W5LIT had a new 1949 Ford in which he installed a surplus ART-13 and a PE-103 dynamotor. For an antenna he wound wire turn by turn on a bamboo pole until it was resonant on a slice of the 75-meter band. When J.L. modulated, Q in the coil produced a tip corona on the first good peak and modulation became loud without a receiver. The 20th edition of the ARRL Antenna Book on page 16-13 says this about continuously loaded antennas: "The general approach has been to use a coil made from heavy wire (#14 or larger), with length-to-diameter ratios as high as 21. British experimeters have reported good results with 8-foot overall length on the 1.8- and 3.5 MHz bands. The idea of making the entire antenna out of one section of coil has been tried with some success." Art`s antenna containing a "full wavelength" of wire would likely feature a greater loss than J.L.`s 1/4-wave resonant coil from simply a greater length of wire while both have peactances balanced to zero. Art`s lower Q would probably kill the corona, increase the bandwidth, while losing the gain that a fullwave straight conductor enjoys. Cecil can probably report on results of continuously loaded mobile antennas versus a bug catcher loaded whip in the California shoot-outs. Best regards, Richard Harrison, KB5WZI There are no loads on my antenna so your statements are irrelavent Art the whole antenna is a load. |
Antenna physical size
Art,
"Why are so many hams alarmed at the idea?" Because of the way you describe things, words used for a distinction between things that just don't make sense. At least that's why I 'wonder' at times. After seeing your 'methods' of doing/saying things, you just don't 'alarm' me much. You DO make me 'wonder' though... - 'Doc |
Antenna physical size
On Mar 9, 7:16 am, wrote:
Art, "Why are so many hams alarmed at the idea?" Because of the way you describe things, words used for a distinction between things that just don't make sense. At least that's why I 'wonder' at times. After seeing your 'methods' of doing/saying things, you just don't 'alarm' me much. You DO make me 'wonder' though... - 'Doc You may be right We will just have to wait and see how things turn out. If it works then I am smart and if it is useless then I fit what everybody thinks of me. No damage done either way. |
Antenna physical size
On Mar 9, 9:23 am, Art Unwin wrote:
On Mar 9, 7:16 am, wrote: Art, "Why are so many hams alarmed at the idea?" Because of the way you describe things, words used for a distinction between things that just don't make sense. At least that's why I 'wonder' at times. After seeing your 'methods' of doing/saying things, you just don't 'alarm' me much. You DO make me 'wonder' though... - 'Doc You may be right We will just have to wait and see how things turn out. If it works then I am smart and if it is useless then I fit what everybody thinks of me. No damage done either way. My replacement antenna for the one I sent away is comming along just fine and I will probably be active on the air in a few weeks. The new one is about two shoe box size and will be connected to a tilt/ scan mechanism so that I can fully determine all the characteristics in real life circumstances. The frequency spread is down to the top of the broadcast band and it will be controlled by my Icom where I will disconect the inbuilt tuner motors and reconnect to my antenna. This should then ensure that the antenna is always in equilibrium screw driver style when I am on the air regardless of the band in use.Hoping to change polarity in QSO's to investigate the differences. Hopefully this summer the pan tilt will also be made automatic for best polarity reception which will then allow for the addition of a dish reflector. Bought myself a new thin Mac laptop which is exciting to use. There is a free NEC 2 program available(cocoanec) so it is getting difficult to determine what to work on. Spring is coming and life is good despite the naysayers. Have a happy day Regards Art |
Antenna physical size
Art Unwin wrote:
On Mar 7, 11:46 am, Jim Lux wrote: wrote: I have searched quite a bit for evidence that states that performance of antennas can be rated by it's size. Formulas do not refere to radiator size or volume and aparture is referenced to gain. I understand that sort of thinking based on Yagi design but the idea that all small radiators are inefficient is rather ludicrouse. My work, based on the sciences of the masters, show that a efficient radiator can be any size,shape and configuration as long as it is in equilibrium . Period No where can I find reference to "size" in what the masters state Regards Art The work by Chu (Journal of Applied Physics, p1163, v19, Dec 1948) and subsequently by Harrington (IEEE Trans Ant & Prop, V18#6, Nov 1965, p896) , Thiele (IEEE Trans on Ant and Prop, v51, #6, June 2003, p1263) and later others, discusses fundamental limits on performance. Watch out, though, for the assumptions in the constraints (e.g. whether the device attached to the feedpoint is reciprocal), and, of course, where the boundary of the system is. Watch out also for the definition of "Q", which in this context is the ratio of stored to disspated/radiated energy, not the ratio of center frequency/bandwidth. In short, there is a tradeoff between Q, directivity, and size. And, because high Q implies high stored energy, for physically realizable antennas with loss, efficiency is in the mix too. Googling "chu harrington limit" often turns up useful stuff. Googled Chu harrington and find that his work is basically empirical around known arrangements. When he brought the question of Q into the picture he made the statement that small antennas are usually of a low impedance which is correct empirically with respect to existing designs but it is not exclusive To summate, my antenna design is considered small yet complies with Maxwells laws and yet does not have a narrow bandwidth or low impedance thus Chu's comments cannot be inclusive of all radiators. Best regards Art which is why I mentioned: "Watch out, though, for the assumptions in the constraints" However, I believe it is incorrect to characterize his analysis as empiricism (i.e. getting experimental data and fitting curves). His analysis (and that of Harrington and Thiele) is entirely theoretical, and actually doesn't deal with loss in the antenna, per se. Indeed, Chu's analysis is based on a simple case (a dipole), but that's more because it's a good first example (and he could use the previous work of Schelkunoff as a starting point). I believe the analysis is generally valid, regardless of what the actual antenna is. |
Antenna physical size
On Mar 10, 11:19 am, Jim Lux wrote:
Art Unwin wrote: On Mar 7, 11:46 am, Jim Lux wrote: wrote: I have searched quite a bit for evidence that states that performance of antennas can be rated by it's size. Formulas do not refere to radiator size or volume and aparture is referenced to gain. I understand that sort of thinking based on Yagi design but the idea that all small radiators are inefficient is rather ludicrouse. My work, based on the sciences of the masters, show that a efficient radiator can be any size,shape and configuration as long as it is in equilibrium . Period No where can I find reference to "size" in what the masters state Regards Art The work by Chu (Journal of Applied Physics, p1163, v19, Dec 1948) and subsequently by Harrington (IEEE Trans Ant & Prop, V18#6, Nov 1965, p896) , Thiele (IEEE Trans on Ant and Prop, v51, #6, June 2003, p1263) and later others, discusses fundamental limits on performance. Watch out, though, for the assumptions in the constraints (e.g. whether the device attached to the feedpoint is reciprocal), and, of course, where the boundary of the system is. Watch out also for the definition of "Q", which in this context is the ratio of stored to disspated/radiated energy, not the ratio of center frequency/bandwidth. In short, there is a tradeoff between Q, directivity, and size. And, because high Q implies high stored energy, for physically realizable antennas with loss, efficiency is in the mix too. Googling "chu harrington limit" often turns up useful stuff. Googled Chu harrington and find that his work is basically empirical around known arrangements. When he brought the question of Q into the picture he made the statement that small antennas are usually of a low impedance which is correct empirically with respect to existing designs but it is not exclusive To summate, my antenna design is considered small yet complies with Maxwells laws and yet does not have a narrow bandwidth or low impedance thus Chu's comments cannot be inclusive of all radiators. Best regards Art which is why I mentioned: "Watch out, though, for the assumptions in the constraints" However, I believe it is incorrect to characterize his analysis as empiricism (i.e. getting experimental data and fitting curves). His analysis (and that of Harrington and Thiele) is entirely theoretical, and actually doesn't deal with loss in the antenna, per se. Indeed, Chu's analysis is based on a simple case (a dipole), but that's more because it's a good first example (and he could use the previous work of Schelkunoff as a starting point). I believe the analysis is generally valid, regardless of what the actual antenna is. You may well be correct. I cannot enter the IEEE papers that you allude to to study it furthur. The fact that my impedences are high and the bandwith is large is really putting me in a unknown area and I have a lot to learn about it Regards Art |
Antenna physical size
You can pretty much sum up the characteristics of small antennas as:
Small - Broadband - Efficient: Pick any two. Roy Lewallen, W7EL |
Antenna physical size
On Mar 10, 1:56 pm, Roy Lewallen wrote:
You can pretty much sum up the characteristics of small antennas as: Small - Broadband - Efficient: Pick any two. Roy Lewallen, W7EL Who knows what "efficiency" represents in the electrical world? It is the word "small" that confuses everybody when the word should be" fractional wavelength". Small and large are meaningles in the antenna world. No I diddn't overlook the sniping. |
Antenna physical size
Jimmie D wrote:
"Roy Lewallen" wrote in message ... You can pretty much sum up the characteristics of small antennas as: Small - Broadband - Efficient: Pick any two. Roy Lewallen, W7EL Don't you mean, You can pretty much sum up the characteristics of antennas as: Small - Broadband - Efficient: Pick any two. Jimmie And what Chu, Harrington, etc., tell you is a mathematical basis for that statement. You can also add "directivity" into the mix. |
Antenna physical size
Art Unwin wrote:
On Mar 10, 1:56 pm, Roy Lewallen wrote: You can pretty much sum up the characteristics of small antennas as: Small - Broadband - Efficient: Pick any two. Roy Lewallen, W7EL Who knows what "efficiency" represents in the electrical world? I think the conventional meaning would be power radiated vs power into the system. If you define "power radiated" to mean "power radiated in a particular direction" then you're adding directivity into the mix. If you define "power into the system" to be 120V Wall power that's different than RF power at the feedpoint of the antenna which is different than RF power out at the output of the transmitter. So, you have to define the appropriate reference plane. The antenna literature tends to draw the boundary at the feedpoint of the antenna, because the rest is "circuit theory". The ham world tends to draw the boundary at the output of the transmitter (so we include loss in feedlines and matching networks), because the FCC power limit is usually measured at that point. (although nothing in the rules says you can't measure after the matching network) In the commercial broadcast world, there's a sort of hybrid, because there's an RF power limit AND a requirement to have a particular field strength in the far field at a particular distance. It is the word "small" that confuses everybody when the word should be" fractional wavelength". Nope.. small in an absolute sense. An antenna that is 10 times bigger will have more directivity or other figure of merit. Applies pretty much whether you're comparing an antenna that is 0.01 wavelength to 0.1 or comparing one that is 10 wavelengths to one that is 100 wavelengths. What you can't say is that the amount of change from 0.01 to 0.1 is the same as from 10 to 100. Small and large are meaningles in the antenna world. They have meaning as far as relative. large is better than small. And, "directive" antennas that are small relative to a wavelength tend to have high Q (in the stored vs radiated energy sense, which may or may not imply narrow bandwidth) It's probably worth finding a library that can get you copies of the papers, rather than relying on interpretations and summaries. The most common misinterpretation is to conceptually equate antenna Q to antenna bandwidth. No I diddn't overlook the sniping. |
Antenna physical size
"Art Unwin" wrote in message ... On Mar 8, 12:25 am, "John KD5YI" wrote: "Brian Kelly" wrote in message ... On Mar 7, 6:09 pm, Art Unwin wrote: On Mar 7, 4:45 pm, "Dave" wrote: "Art Unwin" wrote in message ... On Mar 7, 2:08 pm, (Richard Harrison) wrote: I disagree. Laws written are all based on the assumption of equilibrium and that includes Maxwell's laws. These laws hav e zero refernce to size as such though many would seek because contrary to what those male enhancement product adds tell you, size doesn't matter. for the word volume. Pertinent factors are wave length of frequency in The problem here is that amateur radio is wellded to the yagi design which is not one of equilibrium WAIT JUST ONE GOSH DARN MINUTE! you have said in the past that the simple half wave dipole WAS a prefect example of equilibrium! NOW it isn't??? have you had a new revelation while i had your old email address plonked?? David, You admit to not understanding the term "equilibrium" so what do you care what I say and in what content. If you consider a half wave dipole as being in equilibrium you have to consider the electrical circuit consisting of a capacitance from the antenna to ground or the route thru the center of of the radiator, both of thes circuits can be considered as being in equilibrium. However, on this newsgroup a fractional wavelength radiator is considered as an open circuit for some reason and thus under those circumstances the half wave dipole is not in equilibrium. Now your views on radiation is all over the place so it is very hard for me to determine the context of what you say. Art Long before we rode our dinosaurs to club meetings the bright lights had completely agreed that the strength of radio signals at far off places was a function of the integral of i·dl where dl is the bigness of the aerial. Maybe it's in Sears and Zemansky. I dunno . . nor do I really care. w3rv Antennas for All Applications, 3rd Edition, Kraus & Marhefka, McGraw-Hill, page 12. Begin quote Regardless of antenna type, all involve the same basic principle that radiation is produced by accelerated (or decelerated) charge. The basic equation of radiation may be expressed simply as IL = Qv (A m / s) where I = time-changing current, A/s L = length of current element, m Q = charge, C v = time change of velocity which equals the acceleration of the charge, m/s Thus, time-changing current radiates and accelerated charge radiates. For steady-state harmonic variation, we usually focus on current. For transients or pulses, we focus on charge. The radiation is perpendicular to the acceleration, and the radiated power is proportional to the square of IL or Qv. end quote Cheers, John John If Kraus said "The radiation is perpendicular to the accelleration" then the book is worthless. Review the scalar quantities of a radiator. It is impossible for the resultant to be at 90 degrees to the antenna axis. I suspect the roots of this untruth was the invention of the planar antenna. For maximum horizontal radiation a radiator will be around 10 degrees out of parallel to the earth surface, not parallel. The king is dead, long live the king. Old books just cannot keep up to date Regards Art ie the yagi Art - I was actually replying to W3RV. However, since you piped up... Have you had any books on the subject published? How about research papers? Anything published at all? Do you have any presentations with equations prepared to support your claim? To which companies have you sold your expertise in this field? Have your taught any classes? It is laughable to think anybody would consider you an authority on the subject, much less a greater authority than Kraus or any other contributor to this group. You really should get some psychiatric help to quell those delusions of grandeur you have. Cheers, John |
Antenna physical size
On Mar 11, 8:42 am, "John KD5YI" wrote:
"Art Unwin" wrote in message ... On Mar 8, 12:25 am, "John KD5YI" wrote: "Brian Kelly" wrote in message ... On Mar 7, 6:09 pm, Art Unwin wrote: On Mar 7, 4:45 pm, "Dave" wrote: "Art Unwin" wrote in message .... On Mar 7, 2:08 pm, (Richard Harrison) wrote: I disagree. Laws written are all based on the assumption of equilibrium and that includes Maxwell's laws. These laws hav e zero refernce to size as such though many would seek because contrary to what those male enhancement product adds tell you, size doesn't matter. for the word volume. Pertinent factors are wave length of frequency in The problem here is that amateur radio is wellded to the yagi design which is not one of equilibrium WAIT JUST ONE GOSH DARN MINUTE! you have said in the past that the simple half wave dipole WAS a prefect example of equilibrium! NOW it isn't??? have you had a new revelation while i had your old email address plonked?? David, You admit to not understanding the term "equilibrium" so what do you care what I say and in what content. If you consider a half wave dipole as being in equilibrium you have to consider the electrical circuit consisting of a capacitance from the antenna to ground or the route thru the center of of the radiator, both of thes circuits can be considered as being in equilibrium. However, on this newsgroup a fractional wavelength radiator is considered as an open circuit for some reason and thus under those circumstances the half wave dipole is not in equilibrium. Now your views on radiation is all over the place so it is very hard for me to determine the context of what you say. Art Long before we rode our dinosaurs to club meetings the bright lights had completely agreed that the strength of radio signals at far off places was a function of the integral of i·dl where dl is the bigness of the aerial. Maybe it's in Sears and Zemansky. I dunno . . nor do I really care. w3rv Antennas for All Applications, 3rd Edition, Kraus & Marhefka, McGraw-Hill, page 12. Begin quote Regardless of antenna type, all involve the same basic principle that radiation is produced by accelerated (or decelerated) charge. The basic equation of radiation may be expressed simply as IL = Qv (A m / s) where I = time-changing current, A/s L = length of current element, m Q = charge, C v = time change of velocity which equals the acceleration of the charge, m/s Thus, time-changing current radiates and accelerated charge radiates. For steady-state harmonic variation, we usually focus on current. For transients or pulses, we focus on charge. The radiation is perpendicular to the acceleration, and the radiated power is proportional to the square of IL or Qv. end quote Cheers, John John If Kraus said "The radiation is perpendicular to the accelleration" then the book is worthless. Review the scalar quantities of a radiator. It is impossible for the resultant to be at 90 degrees to the antenna axis. I suspect the roots of this untruth was the invention of the planar antenna. For maximum horizontal radiation a radiator will be around 10 degrees out of parallel to the earth surface, not parallel. The king is dead, long live the king. Old books just cannot keep up to date Regards Art ie the yagi Art - I was actually replying to W3RV. However, since you piped up... Have you had any books on the subject published? How about research papers? Anything published at all? Do you have any presentations with equations prepared to support your claim? To which companies have you sold your expertise in this field? Have your taught any classes? It is laughable to think anybody would consider you an authority on the subject, much less a greater authority than Kraus or any other contributor to this group. You really should get some psychiatric help to quell those delusions of grandeur you have. Cheers, John Let's keep to the subject and put the other comments aside. Do you have any antenna computor programs that you have confidence in? What are they so I can give you thr figures to prove it to yourself Art |
Antenna physical size
On Mar 11, 9:46 am, Art Unwin wrote:
On Mar 11, 8:42 am, "John KD5YI" wrote: "Art Unwin" wrote in message ... On Mar 8, 12:25 am, "John KD5YI" wrote: "Brian Kelly" wrote in message .... On Mar 7, 6:09 pm, Art Unwin wrote: On Mar 7, 4:45 pm, "Dave" wrote: "Art Unwin" wrote in message ... On Mar 7, 2:08 pm, (Richard Harrison) wrote: I disagree. Laws written are all based on the assumption of equilibrium and that includes Maxwell's laws. These laws hav e zero refernce to size as such though many would seek because contrary to what those male enhancement product adds tell you, size doesn't matter. for the word volume. Pertinent factors are wave length of frequency in The problem here is that amateur radio is wellded to the yagi design which is not one of equilibrium WAIT JUST ONE GOSH DARN MINUTE! you have said in the past that the simple half wave dipole WAS a prefect example of equilibrium! NOW it isn't??? have you had a new revelation while i had your old email address plonked?? David, You admit to not understanding the term "equilibrium" so what do you care what I say and in what content. If you consider a half wave dipole as being in equilibrium you have to consider the electrical circuit consisting of a capacitance from the antenna to ground or the route thru the center of of the radiator, both of thes circuits can be considered as being in equilibrium. However, on this newsgroup a fractional wavelength radiator is considered as an open circuit for some reason and thus under those circumstances the half wave dipole is not in equilibrium. Now your views on radiation is all over the place so it is very hard for me to determine the context of what you say. Art Long before we rode our dinosaurs to club meetings the bright lights had completely agreed that the strength of radio signals at far off places was a function of the integral of i·dl where dl is the bigness of the aerial. Maybe it's in Sears and Zemansky. I dunno . . nor do I really care. w3rv Antennas for All Applications, 3rd Edition, Kraus & Marhefka, McGraw-Hill, page 12. Begin quote Regardless of antenna type, all involve the same basic principle that radiation is produced by accelerated (or decelerated) charge. The basic equation of radiation may be expressed simply as IL = Qv (A m / s) where I = time-changing current, A/s L = length of current element, m Q = charge, C v = time change of velocity which equals the acceleration of the charge, m/s Thus, time-changing current radiates and accelerated charge radiates. For steady-state harmonic variation, we usually focus on current. For transients or pulses, we focus on charge. The radiation is perpendicular to the acceleration, and the radiated power is proportional to the square of IL or Qv. end quote Cheers, John John If Kraus said "The radiation is perpendicular to the accelleration" then the book is worthless. Review the scalar quantities of a radiator. It is impossible for the resultant to be at 90 degrees to the antenna axis. I suspect the roots of this untruth was the invention of the planar antenna. For maximum horizontal radiation a radiator will be around 10 degrees out of parallel to the earth surface, not parallel. The king is dead, long live the king. Old books just cannot keep up to date Regards Art ie the yagi Art - I was actually replying to W3RV. However, since you piped up... Have you had any books on the subject published? How about research papers? Anything published at all? Do you have any presentations with equations prepared to support your claim? To which companies have you sold your expertise in this field? Have your taught any classes? It is laughable to think anybody would consider you an authority on the subject, much less a greater authority than Kraus or any other contributor to this group. You really should get some psychiatric help to quell those delusions of grandeur you have. Cheers, John Let's keep to the subject and put the other comments aside. Do you have any antenna computor programs that you have confidence in? What are they so I can give you thr figures to prove it to yourself Art By the way John, read the book and determine why he points to a pitch angle for best results Thus pitch angle is not at right angles so perhaps you can explain that. You can't learn just by belittling facts Art |
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