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#11
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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 |
#12
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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 |
#13
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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 |
#14
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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 |
#15
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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 |
#16
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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 |
#17
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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 |
#18
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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 |
#19
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![]() "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 |
#20
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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 |
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