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where does the power when using an antenna-tuner go to ?
Hi all,
Months ago, when the C-word was something still something far away in a distant land, we had a small discussion in our radio-club. The idea was this: "fundamentals Fridays"(*), a chance to ask questions on aspects of amateur-radio that we all know that are true, but nobody seams to be able to explain why exactly they are the way they are. One of the questions that popped up is this: (although I am not sure of this is a question about physics or about antennas) It is "common knowledge" that when using an antenna with an antenna-tuner, the efficiency of an antenna goes down: the smaller the size of the antenna compared the wavelength, the less power is emitted and the more power is "lost in the tuner". But, why is that? Where does this "lost" energy go to? In essence, the goal of an antenna-tuner is to do impedance-matching: match the impedance of an antenna at a certain frequency to the (50 ohm) output impedance of the transmitter and the transmission-line. For that, it uses inductors or capacitors. (although I know that these components do also have a resistive part, but I think we can ignore this here) Now, I understand that a capacitor can "store" energy in the electrical field between the two plates, and an inductor uses electrical fields to create a current to counter changes in current, ... but why does this create a "lost" of energy? In what form is that energy then "lost"? Is it converted to heat? Is it "emitted"? I've been reading about the "Radiation resistance" of an antenna (**) and, although I am not a physicist, I kind-of understand the notion of the transfer of energy from the momentum of an electron to a photon. But physical process is at work inside an antenna-tuner? And to what kind of energy is the "lost power" converted? Heat? Does an antenna-tuner actually heat up? (again, ignoring the "resistive" loss of the components of the tuner) (*) Fundamental Fridays: (c) EEVblog (**) https://en.wikipedia.org/wiki/Radiation_resistance 73 kristoff - ON1ARF |
where does the power when using an antenna-tuner go to ?
In article , kristoff
wrote: In essence, the goal of an antenna-tuner is to do impedance-matching: match the impedance of an antenna at a certain frequency to the (50 ohm) output impedance of the transmitter and the transmission-line. For that, it uses inductors or capacitors. (although I know that these components do also have a resistive part, but I think we can ignore this here) Kristoff- Are you over-thinking this? The power is lost in resistance. For a great mis-match, currents might be very high in the tuner. Suppose you have a lousy antenna where 50 percent of your power is lost in the transmission line and tuner. Anyone listening to you would suffer a 3 DB reduced signal compared to the ideal antenna. That is one half S-Unit. They probably would not know the difference. Also your lousy antenna may have a poor pattern, transmitting your signal in the wrong direction. The tuner can not fix that. Fred |
where does the power when using an antenna-tuner go to ?
On Fri, 10 Jul 2020 23:27:37 +0200, kristoff
wrote: Does an antenna-tuner actually heat up? (again, ignoring the "resistive" loss of the components of the tuner) Yada, just ignore whatever you don't like. w. |
where does the power when using an antenna-tuner go to ?
Helnut,
On 11/07/2020 10:00, Helmut Wabnig wrote: Does an antenna-tuner actually heat up? (again, ignoring the "resistive" loss of the components of the tuner) Yada, just ignore whatever you don't like. A tuner has a current flowing through it and it has a resistance so it to heat up. But that's not the question. Resistive loss is independent of the frequency. The question is, .. are the other additional physics effects playing here that will cause it to "ventilate" energy? 73 kristoff - ON1ARF |
where does the power when using an antenna-tuner go to ?
HI Fred,
On 11/07/2020 04:57, Fred McKenzie wrote: In essence, the goal of an antenna-tuner is to do impedance-matching: match the impedance of an antenna at a certain frequency to the (50 ohm) output impedance of the transmitter and the transmission-line. For that, it uses inductors or capacitors. (although I know that these components do also have a resistive part, but I think we can ignore this here) Kristoff- Are you over-thinking this? The power is lost in resistance. For a great mis-match, currents might be very high in the tuner. Well, that's the question. (As noted, this is why we called it "fundamental Fridays" :-) ) The reason I kind-of ignored resistive loss as that component is not relative to frequency while the efficiency of an antenna+antenna-tuner system is clearly frequency dependent. It is however an interesting thought that power-dissipation due to resistance can be frequency-dependent via its current. But would this not mean that the efficiency of tuned antenna would be dependent of the design of the tuner and that a theoretical antenna-tuner without resistance would have 100 % efficiency. I have not found this in any documents I have been reading on this. Suppose you have a lousy antenna where 50 percent of your power is lost in the transmission line and tuner. Anyone listening to you would suffer a 3 DB reduced signal compared to the ideal antenna. That is one half S-Unit. They probably would not know the difference. OK, but you can just as easy apply this for -say- an antenna for 475 or 137 KHz band where the efficiency of the antenna-system is ... euh .. less then 50 % (unless you have a very very very big garden :-) ) Also your lousy antenna may have a poor pattern, transmitting your signal in the wrong direction. The tuner can not fix that. That's true and if this was the only effect playing here, then an antenna-tuner would not have a lower efficiency then a fully matched antenna, just a different radiation-pattern. But we all learned at the ham-radio academy that a tuned antenna has a lower efficiency, no? Or where things wrongly represented at the ham-radio lessons? I know. We have been chewing on this question for some time too and so-far have not come up with an answer neither. Every answer seams to produce as many counter-arguments. (I guess that what you get from asking "fundamental" questions) :-( Fred Kristoff - ON1ARF |
where does the power when using an antenna-tuner go to ?
kristoff wrote:
The reason I kind-of ignored resistive loss as that component is not relative to frequency while the efficiency of an antenna+antenna-tuner system is clearly frequency dependent. Well, with so many assumptions already cast in stone, there is not very much to discuss anymore, right? |
where does the power when using an antenna-tuner go to ?
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where does the power when using an antenna-tuner go to ?
On Fri, 10 Jul 2020 23:27:37 +0200, kristoff
wrote: Where does this "lost" energy go to? Mostly into heating the tuner inductors. The Q of the inductors is the major contributor with skin effect being a close second. That's why antenna tuners tend to use big fat silver plated conductors. This T-network antenna tuner simulation might be helpful: http://fermi.la.asu.edu/w9cf/tuner/tuner.html Download the tuner.jar file to your machine. Assuming you have a Java runtime installed, running the program will produce a front panel with adjustment knobs and VSWR meter. To minimize knob twiddling, it has an autotune button. You can adjust the component values and coil Q's with the setup button. The default frequency is in the 160 meter band, where the effects of coil Q are the worst. With the values provided (Q = 100), the tuner loss at 1.83Mhz is 2.0dB (36.3%). Capacitors also have a Q value, but losses from high Q air dielectric caps are minimal. Also, by the same author: "Estimating T-network losses at 80 and 160 meters" http://fermi.la.asu.edu/w9cf/articles/tuner/index.html Mo http://fermi.la.asu.edu/w9cf/index.html -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
where does the power when using an antenna-tuner go to ?
On 11/07/2020 14:57, Jim H wrote:
=================================== Antenna Matching Units ( I prefer not to use the word "Tuner") do have fixed resistance in inductors and wiring as has been stated in this thread. Frank , EI7KS |
where does the power when using an antenna-tuner go to ?
Jim H wrote:
On Tue, 14 Jul 2020 18:07:01 +0100, in , Jeff wrote: On 14/07/2020 14:16, wicklowham wrote: On 11/07/2020 14:57, Jim H wrote: =================================== Antenna Matching Units ( I prefer not to use the word "Tuner") do have fixed resistance in inductors and wiring as has been stated in this thread. No! The amount of inductance varies depending on how much of the inductor is used, thus the resistance of the unit varies with the setting. Resistance also varies with frequency since the skin effect is "deeper" (lower resistance) with lower frequency. And, the antenna resistance to be matched also varies. When the antenna is too short it will have a lower resistance, and thus any fixed losses in tuner and feeder will have a higher relative effect. All in all it is a completely wrong assumption that the losses will be independent from frequency, even when te resistive values in the tuner would be the same. |
where does the power when using an antenna-tuner go to ?
Hi Rob, Jim, Jef, all.
Thanks for continuing on this small thread. As said, I asked this as a fundamental" question, so I am really learning a lot here. (see inline comment) On 15/07/2020 16:27, Rob wrote: Antenna Matching Units ( I prefer not to use the word "Tuner") do have fixed resistance in inductors and wiring as has been stated in this thread. No! The amount of inductance varies depending on how much of the inductor is used, thus the resistance of the unit varies with the setting. OK. makes sense. Resistance also varies with frequency since the skin effect is "deeper" (lower resistance) with lower frequency. Correct me if I am wrong, but it looks to me that these two elements (partly) counter each other. To tune / match an antenna for a lower frequency, you need more inductor wire (i.e. greater resistor), but the skin-effect will be lower. BTW. I always had the idea that skin-effect was only important for frequencies of VHF and higher, not for HF. Are there figures of how much resistances the skin effect adds to a wire, in respect to the frequency? (Just to get an idea of the scale of things) And, the antenna resistance to be matched also varies. When the antenna is too short it will have a lower resistance This is something I do not completely understand. I guess you are talking the radiation resistance, correct? As far as I understand it, the radiation resistance is a "virtual" resistance which is created by the fact that an antenna converts electrical energy in electromagnetic waves that are radiated, thereby extracting energy from the wire. This "loss of energy" in the wire is modelled as a virtual resistance. So, saying "a short antenna has a lower resistance then a full-size antenna", is then the same as saying "a short antenna emits less energy then a full size antenna", which is equivalent to "a short antenna is less efficient" So isn't this a circular reasoning? What exactly is the reason that a short antenna has a lower resistance? .., and thus any fixed losses in tuner and feeder will have a higher relative effect. So, are there are then two different effects at play he - the resistance of the tuner/matching unit which changes with frequency due to the practical way it is build - the radiation resistance of the antenna that changes with frequency. All in all it is a completely wrong assumption that the losses will be independent from frequency, even when te resistive values in the tuner would be the same. 73 Kristoff - ON1ARF |
where does the power when using an antenna-tuner go to ?
kristoff wrote:
BTW. I always had the idea that skin-effect was only important for frequencies of VHF and higher, not for HF. So according to you the use of litze wire in medium wave (1 MHz) radios was a waste of effort? You seem to have a lot of strange ideas... |
where does the power when using an antenna-tuner go to ?
Rob,
On 20/07/2020 10:29, Rob wrote: BTW. I always had the idea that skin-effect was only important for frequencies of VHF and higher, not for HF. So according to you the use of litze wire in medium wave (1 MHz) radios was a waste of effort? You seem to have a lot of strange ideas... Well, what did you expect? I'm just a ham. You know: for 90 % no idea what I am doing as I am just an operator and for 9.9 % "no idea why it is like that, but that's what they told so it must be correct". I'm just trying to fill that 0.1 % of *really* understanding the technology I am using. Usually, I am more into DSP, SDR, data-communication, signal-processing, GNU Radio, etc. Signal processing is based on numeric representations of voltages (amplitude and phase), either the time or frequency-domain, at one particular place in the circuit. The most interesting part of this discussion here is that it requires me to think in a different way that I am used to do, so this discussion is very interesting to me. The problem is that, saying "the skin-effect also has an effect" but without really quantising it does not really help. I still do not have an answer to my question: Are there figures of how much resistances the skin effect adds to a wire, in respect to the frequency? (Just to get an idea of the scale of things) Say for a very basic HF antenna-system: 10 meter coax, balun, full-length dipole for -say- the 40 meter band, designed for 100 Watt RF power. Can you put some numbers of the impact of the skin-effect on this kind of system? 73 kristoff - ON1ARF |
where does the power when using an antenna-tuner go to ?
kristoff wrote:
Rob, On 20/07/2020 10:29, Rob wrote: BTW. I always had the idea that skin-effect was only important for frequencies of VHF and higher, not for HF. So according to you the use of litze wire in medium wave (1 MHz) radios was a waste of effort? You seem to have a lot of strange ideas... Well, what did you expect? I'm just a ham. You know: for 90 % no idea what I am doing as I am just an operator and for 9.9 % "no idea why it is like that, but that's what they told so it must be correct". Well actually this is a bit strange, because a ham usually has to pass an exam, and the theory that has to be learned from that usually includes the basic principles of HF electronics, including a discussion of things like L/C circuits, Q factor, skin effect, etc. But maybe you only did a crash course and pre-learned the 500 questions and their correct answer, without actually understanding it. Well, hopefully you will learn from the current discussion. |
where does the power when using an antenna-tuner go to ?
On 7/21/2020 1:31 PM, kristoff wrote:
Rob, On 20/07/2020 10:29, Rob wrote: BTW. I always had the idea that skin-effect was only important for frequencies of VHF and higher, not for HF. So according to you the use of litze wire in medium wave (1 MHz) radios was a waste of effort? You seem to have a lot of strange ideas... Well, what did you expect? I'm just a ham. You know: for 90 % no idea what I am doing as I am just an operator and for 9.9 % "no idea why it is like that, but that's what they told so it must be correct". I'm just trying to fill that 0.1 % of *really* understanding the technology I am using. Usually, I am more into DSP, SDR, data-communication, signal-processing, GNU Radio, etc. Signal processing is based on numeric representations of voltages (amplitude and phase), either the time or frequency-domain, at one particular place in the circuit. The most interesting part of this discussion here is that it requires me to think in a different way that I am used to do, so this discussion is very interesting to me. The problem is that, saying "the skin-effect also has an effect" but without really quantising it does not really help. I still do not have an answer to my question: Are there figures of how much resistances the skin effect adds to a wire, in respect to the frequency? (Just to get an idea of the scale of things) Say for a very basic HF antenna-system: 10 meter coax, balun, full-length dipole for -say- the 40 meter band, designed for 100 Watt RF power. Can you put some numbers of the impact of the skin-effect on this kind of system? 73 kristoff - ON1ARF Here ya go... you can put in the numbers yourself. https://chemandy.com/calculators/ski...calculator.htm |
where does the power when using an antenna-tuner go to ?
On 7/21/2020 1:31 PM, kristoff wrote:
Rob, On 20/07/2020 10:29, Rob wrote: BTW. I always had the idea that skin-effect was only important for frequencies of VHF and higher, not for HF. So according to you the use of litze wire in medium wave (1 MHz) radios was a waste of effort? You seem to have a lot of strange ideas... Well, what did you expect? I'm just a ham. You know: for 90 % no idea what I am doing as I am just an operator and for 9.9 % "no idea why it is like that, but that's what they told so it must be correct". I'm just trying to fill that 0.1 % of *really* understanding the technology I am using. Usually, I am more into DSP, SDR, data-communication, signal-processing, GNU Radio, etc. Signal processing is based on numeric representations of voltages (amplitude and phase), either the time or frequency-domain, at one particular place in the circuit. The most interesting part of this discussion here is that it requires me to think in a different way that I am used to do, so this discussion is very interesting to me. The problem is that, saying "the skin-effect also has an effect" but without really quantising it does not really help. I still do not have an answer to my question: Are there figures of how much resistances the skin effect adds to a wire, in respect to the frequency? (Just to get an idea of the scale of things) Say for a very basic HF antenna-system: 10 meter coax, balun, full-length dipole for -say- the 40 meter band, designed for 100 Watt RF power. Can you put some numbers of the impact of the skin-effect on this kind of system? 73 kristoff - ON1ARF There is abundant information of the Web about skin effect. Have you even tried searching? Or are you just trolling? |
where does the power when using an antenna-tuner go to ?
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where does the power when using an antenna-tuner go to ?
Ralph, all,
On 21/07/2020 22:52, Ralph Mowery wrote: Well actually this is a bit strange, because a ham usually has to pass an exam, and the theory that has to be learned from that usually includes the basic principles of HF electronics, including a discussion of things like L/C circuits, Q factor, skin effect, etc. But maybe you only did a crash course and pre-learned the 500 questions and their correct answer, without actually understanding it. The test of the last 20 or 30 years have been a joke. Anyone with a memory can pass those without knowing anything. Well, I have this discussion a number of times. (I man a infobooth to promote amateur-radio at FOSDEM -a yearly conference on open-source development in Brussels- so I get to explain this quite a lot) In essence, that is not the problem with the exam itself. When explaining to people why you need to do an exam for amateur-radio, I compare this to a drivers-license. A drivers-license is to show that you are technically capable to drive a car on the public road in a way that is safe for yourself and others on the road. This is very similar to the the amateur-radio exam: it is to make sure that you have sufficient technical knowledge to transmit without interfering with other radio-users and to make sure you do not blow up yourself. The only additional element here is that we are not only allowed to drive a car, but to also build one ourself; so, you have to show you are technically able to build a basic model of a transmitter. So, in essence, the exam still serves it goal: allow all users of the radio-spectrum operate without to much "bumping into each-other". But there is very different problem: The problem is that radio-technology nowadays is nowhere near the technology when the exams where conceived. I did my exam in 1992 (when I was in the 2nd year of what would now be a professional bachelor (digital) electronics). I do not think that the exam has really changed in that 28 years. The "problem" is that technology DID really change. Electronics is now a lot more digital and software, and -especially- the way you do electronics has changed dramatically. I think the exam in Belgium now has just two questions one SDR, one asking of a drawing is a FIR filter and one asking if it is a IIR filter. (and yes, most people just learn it by heart: "is there is line going back from the last block of the drawing to the beginning, , it's answer 2. If not, it is answer 1). In essence, the problem is that the amateur-radio exam requires you to know how to build a car ... a basic model of a car: chassis, 4 wheels, engine, breaks, suspension, fuel, .... However, the reality is that a car build in 2020 is 100 times more complex than that basic model. A modern car is filled with hundreds of sensors and as many microcontrollers that all talk together over any number of CAM-bus. After all, the goal is that -if the driver hits the break and the sensors in the wheels notice that the car is losing grip- some device will take over and -based on the input of a myriad of other sensors determining the state of the car- and try to keep the car going in a direction the driver wants it to go. In amateur-radio terms, almost any device you buy or build these-days is driven by DSP, SDR, microcontrollers, FPGAs, etc. We use plutoSDRs to transmit to QO100, arduino's to drive a PLL as a cheap WSPR beacon in a 3d-printed case and a raspberry-pi as signal-generator for DATV. And the exam does not reflect that. Should it do that? Should there be a question on the amateur-radio exam: "please provide a general overview of the hardware and software for a POCSAG paging transmitter using either an arduino + FM transmitter or a si4332 radio-chip"? I don't think so. .. that is simply not the goal of the exam. But, the problem is that, if you do not require this knowledge for the exam, 99 % of the amateur-radio community is completely clueless on how modern telecommunication-equipment works internally. So either they do not care "I'm just an operator and I know how to use my radio", or they have a very vague idea of how it works. As explained, my interest here is to learn. Antenna's are not my speciality (as you can guess). I learned about them in school (which was good enough to pass the ham-radio exam) but that does not mean I "understand" it. In fact, it was a presentation of my former teacher in our radio-club on the nanovna, the video of a talk by Dr. KC Kerby-Patel at MIT about antenna's beginning this year and a discussion I had at FOSDEM with a somebody working in the physics department of a university that made me for the first time see an antenna in the context of "energy". I have been playing around with the Java tool Jeff pointed out (I'm also trying to really understand the article he has provided) and been playing around with a couple of xnec2 simulations. I kind-of favour the idea that this loss is pure related to the practice components (as Jeff and Jeff have said), but I do not understand how this matches up with a statement that the resistance of a shortened antenna is less then a that of a full-size antenna. Concerning the skin-effect, I did read some information on it, and just tried the tool that John has provided (I already had that formula so it saves me time having to do the calculations :-) ), but the problem is that the result does not really say that much. What does a skin-effect depth of 24.46 μm (copper, 7.1 MHz) say concerning additional resistance to an antenna-system and how to does this compare to other resistive elements in the antenna-system and the overall behaviour? As said, there is a difference between "having learned" and "understanding". 73 kristoff - ON1ARF |
where does the power when using an antenna-tuner go to ?
In article , kristoff
wrote: What does a skin-effect depth of 24.46 μm (copper, 7.1 MHz) say concerning additional resistance to an antenna-system and how to does this compare to other resistive elements in the antenna-system and the overall behaviour? As said, there is a difference between "having learned" and "understanding". Kristoff- I can not discuss the physics of skin effect. I learned of its existence in passing, with the understanding that it is relatively insignificant. For radio systems, I think in terms of Decibels. For voice, in every step between your mouth and the ear of the receiving station, there is a series of stages of positive and negative amplification. You may have 100 Watts peak power coming out of the transmitter. The receiving station might have one Watt peak audio coming out of their speaker. By far, the greatest negative amplification (loss) is between antennas. Fred |
where does the power when using an antenna-tuner go to ?
kristoff wrote:
Well, I have this discussion a number of times. (I man a infobooth to promote amateur-radio at FOSDEM -a yearly conference on open-source development in Brussels- so I get to explain this quite a lot) In essence, that is not the problem with the exam itself. When explaining to people why you need to do an exam for amateur-radio, I compare this to a drivers-license. A drivers-license is to show that you are technically capable to drive a car on the public road in a way that is safe for yourself and others on the road. This is very similar to the the amateur-radio exam: it is to make sure that you have sufficient technical knowledge to transmit without interfering with other radio-users and to make sure you do not blow up yourself. The only additional element here is that we are not only allowed to drive a car, but to also build one ourself; so, you have to show you are technically able to build a basic model of a transmitter. So, in essence, the exam still serves it goal: allow all users of the radio-spectrum operate without to much "bumping into each-other". But there is very different problem: The problem is that radio-technology nowadays is nowhere near the technology when the exams where conceived. However, that does not apply to antennas, the current topic. For antennas, their matching, and the losses, the theory that you (should have) learned for your amateur radio exam still applies today. Maybe you should listen/join the ZX net, every Sunday 9AM on 3603 kHz, where this topic is patiently explained time after time by the moderator Bob ON9CVD. Or check his website or send him a mail asking for some of the talks he has held their on the topic of antenna matching. |
where does the power when using an antenna-tuner go to ?
Hi Rob,
On 22/07/2020 11:09, Rob wrote: The problem is that radio-technology nowadays is nowhere near the technology when the exams where conceived. However, that does not apply to antennas, the current topic. For antennas, their matching, and the losses, the theory that you (should have) learned for your amateur radio exam still applies today. Euh .. why would this not apply to antennas? Modern technology allows you to do a lot of new things that are not at all covered in the exam: Antenna-related technologies like spacial diversity reception, phased antenna-arrays) have become easier to implement with SDR. Using signal-processing, you can much easier modify (e.g. delay) a signal, and you can change that dynamically and -if needed- several times a second. I did talk to somebody at the GNURadio devroom at FOSDEM last year who wanted to make such a setup to track weather-satellites with a setup with three fixed antennas and three phase-locked SDR receivers. The exam mentions antenna-impedance and antenna tuners, but in how many clubs has there been a workshop on how (say) the hardware and software of an magnetic loop automatic antenna-tuner actually works. (I know of one club where this has been done .. :-). Same thing for tools. In how many clubs has the topic of (say) antenna simulation tools. I went to a club where there was a presentation on this topic. I was actually the only person who took the time to try this out myself beforehand and who had a real antenna with me. When after the presentation, I proposed "you know, why don't we do a workshop on this, say 5 people. Everybody brings an antenna and we can all together try to create a model of it so we can really learn the tool". The responds was ... euh .. overwhelming. (sarc) I've been trying for years now to find somebody who can give a workshop on how to design a path-antenna. No success. The same thing for physical design technology (3D printing, CNC milling, ....) for antenna applications. There now even is technology where an FPGA on the antenna is use to connect / disconnect parts of an antenna and to control the polarisation of the antenna. You can actually do it so fast that you can use it to encode bits of a digital transmission in the polarisation of a signal. (apparently, 5G will use this). Maybe you should listen/join the ZX net, every Sunday 9AM on 3603 kHz, where this topic is patiently explained time after time by the moderator Bob ON9CVD. Or check his website or send him a mail asking for some of the talks he has held their on the topic of antenna matching. Thx I will contact him. Perhaps he can help me to understand how an antenna system actually works from a physics perspective. 73 kristoff - ON1ARF |
where does the power when using an antenna-tuner go to ?
Hi Jeff,
On 28/07/2020 11:07, Jeff wrote: The problem is that radio-technology nowadays is nowhere near the technology when the exams where conceived. However, that does not apply to antennas, the current topic. For antennas, their matching, and the losses, the theory that you (should have) learned for your amateur radio exam still applies today. Euh .. why would this not apply to antennas? I think what the OP is trying to say is that antenna theory has not changed over the years, and Maxwell's equations, transmission line theory etc. still apply and have not been superseded. There has been no great leap in antenna technology compared to other branches of radio communications. What was good 50 years ago is still good today. Well, I did use the term antenna *systems* with a reason :-) But in essence, that's not the point. This message-thread is actually a reply to a message saying that the exam has become to easy. The way I see it, it is not the 90 % "operator" hams that will determine the future of amateur-radio. Operators follow the technology as it become available (DIY, commercial) and, in that sense, how easy or difficult the exam is not that relevant. What is important are the 5 to 10 % technically-minded part of the amateur-radio community, the people who are busy building and designing things, either creating new devices or combining devices to build infrastructure in a novel way. (and, to be honest, I consider this NG part of that). For me, that is the group of people that will make amateur-radio survive in the 21st century. 20 to 30 years ago, most devices consisted of one type of technology, and that was either "analog" or "digital". (with some exceptions, like using a PC to do RTTY) But in 2020, almost all devices are now a mix of analog, digital-control and digital-processing technologies, that might even use a LAN or PAN network to connect to a backend-infrastructure and do data-processing or even ML. (See the examples of the combination of antenna-technology with fields of technology like like digital-control and digital-processing in the previous message.) And that aspect makes things now completely different from technology 20 years ago: as devices have become a mix of different technologies, so has become the requirements for people interesting in developing new things. So, yes, I agree. Antenna-technology by itself is one of the fields that has changed less then other technologies; but antennas + digital-control + digital-processing + simulations + "data" + whatever is nowhere what was possible 20 years ago. Anycase, let's hope that we can find a way to get sufficient technically-minded people from ham-community interested in taking the next step so the hobby can survive in the 21st century. (but as we have now gone quite off-topic here, I propose to close this discussion) Jeff 73 kristoff - ON1ARF |
where does the power when using an antenna-tuner go to ?
Hi Jim,
Just a quick reply. On 30/07/2020 20:09, Jim H wrote: For me, that is the group of people that will make amateur-radio survive in the 21st century. Surely you're kidding... or didn't think it through well enough. It takes the other 90 - 95% (using your 5 - 10% figure) to create the critical mass needed to keep the equipment manufacturers in business... without which the hobby/service won't survive. Even if the 5 - 10% make their own rigs, we wouldn't have a critical mass of licensees to lobby successfully to keep our frequencies if our ranks were to consist of only the 5 - 10%. I think you do not really understand this issue here. This is not about boxes. "making your own rig" and "designing new technology" are two completely different things: - You can build your own radio, but just use it do plain old CW or SSB. - You can use a commercial rig to try out if by using a different FEC-system you can make GMSK-based codec2 digital-voice more robust to slow-fading then FM on 10 meter Es DX. By definition, amateur-radio is "a scientific / technical hobby that deals with everything related to radio, radio-communication and radio-technology". If you equate technology to just the device, then you're a user. If you understand and are able to manipulate the ideas behind that technology, then you are can determine the future of that technology, and of amateur radio! That is what the 90 / 10 % is about! 73 kristoff - ON1ARF |
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