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#1
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I find this topic very interesting, including the mandrill part
![]() We all want to have small, broadband, eficient antennas. I believe Art is right in his original post, today we can have all these characteristics in the same package. There is no law of physics forbidding that. Through advances in computation power we can achieve today in months what took decades in the past and there is much research directed at these kinds of new antennas. Eventually everyone will be able to choose and model his own antenna based on the characteristics one wants, but without the cumbersome dimensions, without significant bandwith limitations, without major efficiency compromises. I believe the tradeoff (for it has to exist one) will be ease of manufacturing. Incidentally these new antennas have a lot to do with what Art defines as equilibrium although I don't think he has a clear enough definition. But it's all related to patterns, patterns which can be found everywhere in nature an which can be expressed almost entirely through matemathical formulas. Scaling of antennas is clearly possible, despite of what the Chu-Harrington limit states ( or to be fair, by applying them in a new way ). I eagerly await the day when the 80 meter dipole will be replace by a small device the size of a shoe box ( although it might be a bit larger in the beginning ![]() Regards, Robert |
#2
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#3
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![]() "Richard Clark" wrote in message news ![]() On Mon, 31 Mar 2008 14:11:00 -0700 (PDT), wrote: Eventually everyone will be able to choose and model his own antenna based on the characteristics one wants, but without the cumbersome dimensions, without significant bandwith limitations, without major efficiency compromises. Hi Robert, 50 years ago they said Electricity would be so easy to produce they would pay us to use it. They ignored Hiroshima and discovered Chernobyl. 40 years ago they said DNA and genetics would allow us to design our own babies. They ignored Thalidomide and discovered Dolly the sheep that died before her time. 30 years ago they invented modeling software that would allow us to create the Gaussian dipole (or whatever) and discovered every dipole that came before it performed better. Nearly 20 years ago Johnny Carson retired and we are still getting jokes. Not nearly 10 years ago with the Dow at 11658 and a budget surplus at 230 billion, the Republicans promised prosperity was around the corner and their voters are now living in cardboard boxes with the Dow at 12176 and the national debt up 50%. Scaling of antennas is clearly possible, despite of what the Chu-Harrington limit states ( or to be fair, by applying them in a new way ). But you don't know how, and have never seen one either. 73's Richard Clark, KB7QHC Hi Richard, I have a pair of computer speakers sitting on my desk that completely out perform the so called ultimate hi-fi floor mounted tower system speakers I bought 35 years ago for the equivalent of several thousand dollars in today's money. The old speakers still work just fine but the audio experts have learned how to squeeze that performance out of a speaker that old audio theory predicted couldn't possibly work. Just how does a 3 inch speaker in a cabinet the size of a couple of books manage to produce notes from 20 Hz - 20 kHz? To be fair, the small speakers can't fill a room with sound in the same smooth way that a larger speaker cabinet can, but for everyday use in a small modern house or apartment they are more than adequate for the majority of people. It seems to me that Art and others are pursuing a similar path at RF. The aim being to produce an antenna that punches out a signal from a physically small area. It may not perform quite as well as a full size half or full wavelength antenna, but it will work well enough for most people with small gardens or limited real estate for an antenna farm. Clearly there are considerable differences in dealing with sound waves and RF but I believe that a principle has been established that it is possible to 'simulate' the performance of a larger system using physically small components. Art may not be the first to get there, but he seems to be having a damn good try and someone, somewhere will eventually succeed. Mike G0ULI |
#4
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On Mar 31, 5:47 pm, "Mike Kaliski" wrote:
"Richard Clark" wrote in message news ![]() On Mon, 31 Mar 2008 14:11:00 -0700 (PDT), wrote: Eventually everyone will be able to choose and model his own antenna based on the characteristics one wants, but without the cumbersome dimensions, without significant bandwith limitations, without major efficiency compromises. Hi Robert, 50 years ago they said Electricity would be so easy to produce they would pay us to use it. They ignored Hiroshima and discovered Chernobyl. 40 years ago they said DNA and genetics would allow us to design our own babies. They ignored Thalidomide and discovered Dolly the sheep that died before her time. 30 years ago they invented modeling software that would allow us to create the Gaussian dipole (or whatever) and discovered every dipole that came before it performed better. Nearly 20 years ago Johnny Carson retired and we are still getting jokes. Not nearly 10 years ago with the Dow at 11658 and a budget surplus at 230 billion, the Republicans promised prosperity was around the corner and their voters are now living in cardboard boxes with the Dow at 12176 and the national debt up 50%. Scaling of antennas is clearly possible, despite of what the Chu-Harrington limit states ( or to be fair, by applying them in a new way ). But you don't know how, and have never seen one either. 73's Richard Clark, KB7QHC Hi Richard, I have a pair of computer speakers sitting on my desk that completely out perform the so called ultimate hi-fi floor mounted tower system speakers I bought 35 years ago for the equivalent of several thousand dollars in today's money. The old speakers still work just fine but the audio experts have learned how to squeeze that performance out of a speaker that old audio theory predicted couldn't possibly work. Just how does a 3 inch speaker in a cabinet the size of a couple of books manage to produce notes from 20 Hz - 20 kHz? To be fair, the small speakers can't fill a room with sound in the same smooth way that a larger speaker cabinet can, but for everyday use in a small modern house or apartment they are more than adequate for the majority of people. It seems to me that Art and others are pursuing a similar path at RF. The aim being to produce an antenna that punches out a signal from a physically small area. It may not perform quite as well as a full size half or full wavelength antenna, but it will work well enough for most people with small gardens or limited real estate for an antenna farm. Clearly there are considerable differences in dealing with sound waves and RF but I believe that a principle has been established that it is possible to 'simulate' the performance of a larger system using physically small components. Art may not be the first to get there, but he seems to be having a damn good try and someone, somewhere will eventually succeed. Mike G0ULI Mike, I am already there. Regardless of the confidence I have in my own findings I have cinsented for a stanger in another state to test it in a way he feels comfortable with. I might also remind you that the antennas are Small full wave antennas which vastly different to electrically small antennas that is often written about by many including Chu! As far as equilibrium goes it is adviseable to go back a few hundred years when scientists observed a static bubble and wove a mathematical response to their puzzle. Most people on this thread do not have a thorough understanding of the masters laws which are derived around the term equilibrium. Many were agast at the idea of adding a time variable to Gaussian law since the correllation between a closed boundary and equilibrium was to complicated for them to understand. Then there were those who disliked the idea of static particles being electrons and wanted me to state it was a part of an electron that passed in a straight line thru the atmosphere. These people will go into a state of shock if I called partices by the name of neutrinos no less. All because of the stance they have taken that all is known about radiation. It was the small step that I took that scientists have been looking for for years when they began to lose faith in classical physics snd the laws of Newton and turned to address numourous new sciences for answers.Now they may retreat and bind themselves more firmly to the classical science and the pursuit of a universal law which Einstein seached so hard for. As far as 'all is known' older people hate change with a vengence and will fight to the death against it with the short time they have left on this earth . Fortunately the younger generation always comes along with an inquisitiveness that cannot be suppressed and are willing to rebuild where past structures disappear below the sands. Small FULL WAVE radiators are here now where a single element can supply the same gain as a planar array. Single elements that can be made with two degrees of freedom that can also be stacked to add an extra degree of freedom for the smallest WiFi device. I now await the standard comments that comes along after each of my patents, I new that already! It is really not all that special! It was me who gave you the idea in the first place. Anybody can get a patent ! That was already known and invented before. It is not my fault that people didn't make it earlier! What use is it? We already have good antennas! Yup. Small full wave antennas are now here that can cover all frequencies, not just all bands! Moxon was just a tad to late to see the new antennas for small gardens in the U.K. Best regards Art Unwin KB9MZ....xg (uk) |
#5
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On Mon, 31 Mar 2008 23:47:00 +0100, "Mike Kaliski"
wrote: Hi Richard, I have a pair of computer speakers sitting on my desk that completely out perform the so called ultimate hi-fi floor mounted tower system speakers I bought 35 years ago for the equivalent of several thousand dollars in today's money. Hi Mike, I have a set of 30 year old Pioneers that still kick ass. The Pioneer amp feeding any other set drives them into distortion where the Pioneer speakers still have more range to go. Never needed to push the amp above 4 to be heard outside. OK, so much for the merits of qualitative reports, otherwise known as testimonials. Proves nothing. The old speakers still work just fine but the audio experts have learned how to squeeze that performance out of a speaker that old audio theory predicted couldn't possibly work. Magnetics got better, and theory stayed the same. Performance followed the theory's prediction of new magnetics is all. This isn't a mystery is it? Care to name your speakers' model and manufacturer, or did you form the cone and wind the voice coils around a selected magnet by hand? 73's Richard Clark, KB7QHC |
#6
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![]() "Richard Clark" wrote in message ... On Mon, 31 Mar 2008 23:47:00 +0100, "Mike Kaliski" wrote: Hi Richard, I have a pair of computer speakers sitting on my desk that completely out perform the so called ultimate hi-fi floor mounted tower system speakers I bought 35 years ago for the equivalent of several thousand dollars in today's money. Hi Mike, I have a set of 30 year old Pioneers that still kick ass. The Pioneer amp feeding any other set drives them into distortion where the Pioneer speakers still have more range to go. Never needed to push the amp above 4 to be heard outside. OK, so much for the merits of qualitative reports, otherwise known as testimonials. Proves nothing. The old speakers still work just fine but the audio experts have learned how to squeeze that performance out of a speaker that old audio theory predicted couldn't possibly work. Magnetics got better, and theory stayed the same. Performance followed the theory's prediction of new magnetics is all. This isn't a mystery is it? Care to name your speakers' model and manufacturer, or did you form the cone and wind the voice coils around a selected magnet by hand? 73's Richard Clark, KB7QHC Hi Richard, Never one to refuse a challenge. The old speakers were a pair of Celestion Ditton 15XR's with 30 watt per channel rating and a flat sound response output from around 20Hz to 20kHz, 104db at 1 yard driven with 1 watt. The XR stood for extended range indicating that the speaker design had been modified and upgraded from the original Ditton 15 specifications. The new speakers I mentioned are a pair of Creative T20's. 14 watts per channel from a built in amp and very nice to listen to. They don't really compare with the Celestions for the smooth mellow sound that only seems to come with wooden cabinets, but for the price they are excellent. Good point about the magnets though. The super high powered magnets, ultra rigid, lightweight fibre glass cones and developments in ported cabinet design have all contributed to the superb performance of the T20's. Apparently they have been out for a while now, but it was only when I was wandering about in a PC World store that I heard a pair up and running. I was stopped in my tracks by the sound coming out of these tiny devices and spent a good couple of minutes looking for the subwoofer unit that I felt sure was hidden away somewhere. There wasn't a subwoofer and after that, I just knew I had to buy a pair. I have no connection with Creative and in fact I am a bit annoyed with the company's attitude to (not) providing proper sound card drivers for Windows Vista. Anyway, just go and check out the web reviews. Sorry everyone else, but this bit hasn't really got anything at all to do with antennas. Cheers Mike |
#7
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"Mike Kaliski" wrote in
: Apparently they have been out for a while now, but it was only when I was wandering about in a PC World store that I heard a pair up and running. I was stopped in my tracks by the sound coming out of these tiny devices and spent a good couple of minutes looking for the subwoofer unit that I felt sure was hidden away somewhere. There wasn't a subwoofer and after that, I just knew I had to buy a pair. I have no connection with Creative and in fact I am a bit annoyed with the company's attitude to (not) providing proper sound card drivers for Windows Vista. Wait for Windows 8. It can't be worse! Anyway, just go and check out the web reviews. Sorry everyone else, but this bit hasn't really got anything at all to do with antennas. What must be really wonderful is how these speaker manufacturers have not only managed to change resonant points, but managed to get these very small systems to move the massive amounts of air needed with the small speaker systems involved! Oops, sorry, I got sarcastic.. While it is true that we can get better sound from smaller speaker systems than we have been able to in the past, we have to keep in mind that those advances are available for the full size systems too. IOW, all things being equal..... No new physics are needed. |
#8
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On Thu, 3 Apr 2008 02:33:20 +0100, "Mike Kaliski"
wrote: Hi Richard, Never one to refuse a challenge. The old speakers were a pair of Celestion Ditton 15XR's with 30 watt per channel rating and a flat sound response output from around 20Hz to 20kHz, 104db at 1 yard driven with 1 watt. The XR stood for extended range indicating that the speaker design had been modified and upgraded from the original Ditton 15 specifications. Hi Mike, Pretty impressive. My own Pioneers fall 10dB below that. The new speakers I mentioned are a pair of Creative T20's. 14 watts per channel from a built in amp and very nice to listen to. Good to have a recommendation there too. They don't really compare with the Celestions for the smooth mellow sound that only seems to come with wooden cabinets, but for the price they are excellent. Good point about the magnets though. The super high powered magnets, ultra rigid, lightweight fibre glass cones and developments in ported cabinet design have all contributed to the superb performance of the T20's. Apparently they have been out for a while now, but it was only when I was wandering about in a PC World store that I heard a pair up and running. I was stopped in my tracks by the sound coming out of these tiny devices and spent a good couple of minutes looking for the subwoofer unit that I felt sure was hidden away somewhere. There wasn't a subwoofer and after that, I just knew I had to buy a pair. I would have to agree. I have no connection with Creative and in fact I am a bit annoyed with the company's attitude to (not) providing proper sound card drivers for Windows Vista. Maybe with service pack 4. Anyway, just go and check out the web reviews. I will. Sorry everyone else, but this bit hasn't really got anything at all to do with antennas. But it does show how performance correlates to numbers to theory to practice - something dreadfully missing in Art's contributions, if you can call throwing claims against the wall to see what sticks as a contribution. 73's Richard Clark, KB7QHC |
#9
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Richard Clark wrote:
But it does show how performance correlates to numbers to theory to practice - something dreadfully missing in Art's contributions, if you can call throwing claims against the wall to see what sticks as a contribution. Or one's underwear... - 73 de Mike N3LI - |
#10
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Mike Kaliski wrote:
Hi Richard, I have a pair of computer speakers sitting on my desk that completely out perform the so called ultimate hi-fi floor mounted tower system speakers I bought 35 years ago for the equivalent of several thousand dollars in today's money. The old speakers still work just fine but the audio experts have learned how to squeeze that performance out of a speaker that old audio theory predicted couldn't possibly work. Just how does a 3 inch speaker in a cabinet the size of a couple of books manage to produce notes from 20 Hz - 20 kHz? To be fair, the small speakers can't fill a room with sound in the same smooth way that a larger speaker cabinet can, but for everyday use in a small modern house or apartment they are more than adequate for the majority of people. It seems to me that Art and others are pursuing a similar path at RF. The aim being to produce an antenna that punches out a signal from a physically small area. It may not perform quite as well as a full size half or full wavelength antenna, but it will work well enough for most people with small gardens or limited real estate for an antenna farm. Nope.. there's a significant difference between the speakers and the antenna, and that's the fact that the amateur user of the antenna is power limited (by regulation). In the speaker case, they trade off efficiency (acoustic watts out for electrical watts out) because electrical watts are cheap these days (not so back in McIntosh tube amp days...) You can tolerate a 1% efficient design that puts out 100mW of acoustic power with 10W electrical power in. (note that 120dB SPL = 1 Watt.. a symphony orchestra, at full tilt, is about a watt of acoustic power, and I daresay you couldn't tolerate a whole orchestra in your office) OTOH, a 1% efficient antenna design is pretty crummy. A dipole is probably on the order of 70% efficient (RF power radiated into the far field vs RF power at the feedline). A mobile antenna (which everyone will agree is not particularly efficient, even if you argue about the actual magnitude) might be 5-10% efficient (10dB down). As a practical matter, you can get away with a 1% efficient antenna, particularly if you're not looking for "link reliability"... The propagation loss between you and some arbitrary point could easily vary by 100 dB, so you just wait until propagation is "good enough" to work the guy with the 0.1W you radiate. Of such are "worked 300 countries on two bedsprings" sorts of stories made. Folks work around the world on less than a watt radiated, just not "on demand".. they keep trying until conditions are just right and they "get lucky". So, on that basis, you could probably fire up your 1500W amplifier into a compact loop antenna that's a meter in diameter, and work the world, eventually. Clearly there are considerable differences in dealing with sound waves and RF but I believe that a principle has been established that it is possible to 'simulate' the performance of a larger system using physically small components. Art may not be the first to get there, but he seems to be having a damn good try and someone, somewhere will eventually succeed. Mike G0ULI |
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