In the video Standing Up For Standing Waves (search TH-cam) Bill Hays starts with the idea that all an antenna tuner does is make your transmitter happy, which many in his audience (members of a repeater club) agreed with. He then showed (not told) them that what it really does is make the antenna happy. He made a point: you don't care about your transmitter,as long as it's putting out full power and not getting hot, you care about the other guy's receiver. Adding a conjugal match somewhere between the transmitter and the antenna caused the latter to radiate at virtually full power.
Word salad to justify a common misunderstanding. Matching networks (essentially the same circuit hams call an antenna tuner) are tuning AM broadcast towers all over the world every day to resonate at the station's operating frequency. How do they think WLW gets their 5/8 wave tower to work? Used properly, it WILL tune the antenna!
@@CoffeeandHamRadios I think you have a basic misunderstanding of conjugate match. When you add reactance to an antenna circuit, which occurs when "j" is not 0, you change its resonant frequency. I have worked at many AM stations whose towers are not the correct height to be naturally resonant at the operating frequency. They are tuned to electrical resonance by the conjugate match, typically using a Pi network. Antenna tuners are so called because, by adding reactance, they change an antenna's resonant frequency.
@@CoffeeandHamRadios Here's what I think is the issue. You are looking at the antenna and the matching network as separate pieces. Let's say you have an antenna which is not naturally resonant at the carrier frequency. It is connected to the transmitter by a properly adjusted matching network. What is happening? You place an Operating Impedance Bridge between the matching network and antenna and see the complex impedance, with a reactive component, since the antenna is not naturally resonant at the carrier frequency. Place the OIB between the transmitter and the matching network and you see 50+j0, resonant at the carrier frequency. The matching network has matched the transmitter to the antenna, just as you say. But what about resonance? In a resonant circuit, the electric current oscillates at its resonant frequency. An antenna has a natural resonant frequency because of its length and the speed of electric propagation along its length. But, in the example above, at what frequency is the antenna current oscillating? It is oscillating, not at the antenna's natural resonant frequency, because the current is oscillating through the conjugate matching network as well as the antenna. Nowhere in the system, not in the antenna nor in the matching network, is current oscillating at the antenna's natural resonant frequency. This is why we say that the conjugate match has tuned the antenna to a new resonant frequency. So, a conjugate matching network can properly be called an antenna tuner because it does tune the antenna's resonant frequency.
The way i understand conjugate match between the antenna and tuner is that the the antenna feedpoint is equal and opposite in phase with the tuner output, wouldn't that make the antenna feedpoint resonant, is this why Maxwell constantly refers to the antenna as being tuned to resonant in his books ? The reflected power being in phase with the forward power would then add to it ,its not creating more power rather conserving the original power put into the system, obviously in real world applications there will be some loss within the feedline which may or maynit be an issue depending on frequency, main point being the tuner is helping the transmitter to produce its maximum power into the system without causing damage to transmitter
This is exactly what I was trying to convey. But the ATU doesn't change a single characteristic of the antenna, right? If you tune a piano or a guitar you change the wire right?
@@CoffeeandHamRadios you can't compare a musical instrument with an antenna, a musical instrument must be resonant to make the note you require an antenna doesn't need to be resonant to radiate efficiently, If the conjugate match is present between the tuner and antenna feedpoint there must be resonance there also ,therefore with the feedpoint being resonant then the antenna is surely, if there's no conjugate match between tuner and antenna then there's no power transfer and you tuner would heat up
No, I fully understand what is happening. I think we agree on what is taking place but you want to say "it's tuning the antenna" and I disagree and I think it's matching impedance, the antenna itself isn't being tuned. It really doesn't matter to me what language we use to describe the exact same process... for some reason it seems to matter to you.
Your method and analysis are right on. With low loss, tuning at the rig end also presents a good match to the antenna. This can be shown using Smith Charts, either paper or computer aided, or using Dean Straw's TLW program which comes with the ARRL antenna book. It can also be shown experimentally by putting 50 ohms on the transmitter side of the tuner and looking back down the coax towards the tuner, and comparing the measured complex Z and the complex Z of the antenna. They will be nearly conjugates of each other. This understanding is what can be proven and should be understood by all parties. One should also understand that as losses in either the tuner or the line increase, the ability of the tuner to provide this conjugate match to the antenna is compromised, although it still works to some extent. All the rest is just definitions, like where does the antenna stop and the "not antenna" (coax, etc) start. Before we can answer "does the tuner tune the antenna" we have to have agreement on the terms "tune" and "antenna" and that is where the discussion goes into unproductive areas.
Could adding and subtracting capacitance to create resonance be classed as tuning Could the feedline be acting as an extension lead for the antenna feedpoint
I try not to get too wrapped up in the theory and terminology. I have no issue using a tuner if necessary. At the end of the day, if I can make contacts and my transceiver is happy, all is well with me.
I think its a holy war where people just try to one up each other. There seems to be a group that likes to troll antenna tuner videos specifically looking to argue...
In the old days the tuner was actually in the transmitter. It was called a pi network. I don’t recall any hams or engineers I knew saying the coax had to be half wave long. I think maybe that was a CB myth. Today the tuner at the transmitter does the same thing it matches the fixed 50 ohm output of the new rigs to whatever is at the transmitter end of the coax. The feedline to antenna mismatch remains the same. The power ( let’s say 100 watts) is delivered from the transmitter into the feedline. In its travel from the transmitter to the antenna it is attenuated some amount. That’s the inherent loss of the coax. Let’s say it’s 3dB ( easy number to work with). Half of that 100 watts is lost in the coax. So 50 watts reaches the antenna. With a perfect match almost the complete 50 is radiated. However with a 2:1 SWR there will be voltage and current reflections. Reverse power or reflected power it’s sometimes called. So some power gets radiated but some is reflected. In the case of a 2:1 SWR that’s about 5 watts reflected. Of that 5 watts only about 2.5 gets back to the transmitter. ( 3dB loss in the cable). Essentially that 2.5 watts gets reflected back to the antenna. Again half of that is lost so only 1.5 watts makes it to the antenna, where 10% or .15 watts are reflected and half of that ( 0.075 watts) is lost on the return trip. Let’s stop here. Total loss in the feedline with the matched antenna was 50 watts. With the 2:1 SWR the loss was the sum of the losses first 50 watts, then 2.5 watts and then 1.5 watts. Total loss for the 2:1 SWR case was 50+2.5+ 1.5 equals 54 watts in our truncated example. The loss in the matched case was 50 due to coax loss. In the 2:1 case the loss increased by 4 watts. In dB that’s 3 dB loss for the matched case and less than 3.4 dB loss for the 2:1 SWR case. There are charts in all the antenna books that will give you the additional loss in coax due to SWR. That is based on the inherent or matched loss of that coax. The higher the coax loss the higher the loss due to SWR. Of course all this is based on the proper match at the transmitter end to allow the transmitter to supply power to the antenna system and to cause a 100% reflection of any reflected power back toward the antenna. The tuner may not actually tune the antenna, obviously it does not create a match between the coax and the antenna, but it does create a situation where the transmitter can deliver rated power into the coax where it can all be used up either as heat in the coax ( be it one trip or many trips bouncing back and forth) or eventually radiated. Each installation is different and loss needs to be evaluated and a determination made as to how much loss is acceptable. Also the transmitter end of the coax needs to be matched somehow so that all power reflected from the antenna terminals that makes it back to the transmitter is reflected back towards the antenna where it can either be attenuated in the coax or radiated by the antenna. So does the tuner tune the antenna? Depends on what you mean by tune! It does not match the coax to the antenna. I think it does set up a resonant condition. Is that tuning the antenna? Maybe….
@dandypoint Your comments are helpful but need one clarification. It is very true that definitions are what are the main dividing point in this argument, and so I would mention one thing. When you say "obviously it does not create a match between the coax and the antenna" you very likely mean that the tuner does not create a match between the Zo of the coax (typically 50 ohms) and the Z looking into the antenna, in your example either 25 or 100 ohms. The tuner changes nothing about the antenna itself, and also nothing about the Zo of the line, so it is indeed obvious those ratios are unchanged. Those ratios determine the actual value of SWR on the line, so that also is unchanged. But the tuner does change the Z looking towards the transmitter/receiver as seen by the antenna. In the 100 ohm case, the Z the antenna sees looking into the coax is not 50 ohms, but something closer to 100 ohms as a result of the tuner. An example I did with a particular coax and length to get 3 dB loss gave 64 + j11.3. This was calculated with the TLW program that comes with the antenna book using 20.5 meters of RG-174 at 14 MHz. This represents an SWR seen by the antenna of 1.6:1. A 50 ohm load at the transmitter end but without the tuner, the SWR for the antenna looking into the line would be 2:1, So in this rather lossy case, the tuner only partly matches the antenna to the line. (2:1 down to 1.6:1) If the above calculations are done with a 1 dB line, the antenna to coax conjugate match is much better. With a lossless tuner and a lossless line, the antenna sees looking into the 50 ohm line will be its exact complex conjugate. This is the point of this whole video.
@@JohnStanley-m3t yes. The ideal is to have the coax see an impedance of 50 + j0 ohms. When it does not it becomes an impedance transformer. Transforming the antenna Z to some other R and X at the transmitter end depending on transmission line characteristics and length. Then you accept the loss on the line due to using that particular line plus the additional loss due to SWR. The additional loss may be very small if the coax has low loss to start with. Then the tuner needs to get the power into the coax. That used to be in the transmitter itself and now it’s usually in a separate box called a tuner. Sounds like you have a good handle on it. I was trying to ahead some additional light on the subject from the perspective of an old time ham plus EE. That’s hard to do sometimes.
I don't use an antenna tuner. As a matter of fact I don't even use an antenna, I just hang the coax out the window and let the free wind take the signal.
It's definitely some kinda misunderstanding of Maxwells terminology , what does he mean when he states the antenna feedpoint impedance is tuned by the output of the feedline which is the conjugate of the tuner output, I see that as the feedline has a conjugate match between the tuner and the antenna feedpoint therefore being that the reactance has been cancelled out at the antenna feedpoint creating a resonant feedpoint therefore a resonant antenna Is this not the interpretation of others?
@Pioneer936 the best explanation I've seen recently was in a Facebook antenna group, by Tom, W8JI. His explanation made the most sense to me of any I read. It doesn't jive with what is said in these videos either, and that's because he understands what Maxwell meant, and most of us(including these videos) don't. The signal doesn't bounce back and forth, and eventually decide to exit the antenna. The wave is standing, just like it sounds like it is.
It is the understanding; bit like I have to keep replying to (over and over) is that is should like you are matching the antenna impedance not tuning the antenna. Call it whatever you want, it really doesn't matter. You seem to like claiming to have some secret that others simply don't understand.
Both sides of this argument are right to some extent, and both are wrong. Think about this: what is "power"? To calculate power, you must provide context of other variables: voltage, resistance, impedance, etc. This is one reason why high voltage electricity transmission lines are used. Most amateur radio power meters measure power in the context of a 50-ohm load. If the antenna (or antenna system) is not 50 ohms, then the power reading must be considered in that context. When that other guy says on his youtube channel that power is created when SWR is present, and then shows a "power meter" to prove his point, he is completely misunderstanding the context of a power measurement. Whether an antenna tuner actually tunes an antenna is also subject to context....and at the end of the day, it doesn't really matter as long as the transmission line is of good quality and the mismatch is not significant to cause significant loss of power due to heat in the transmission line. "Significant" is also subjective, since radiated signal effectiveness is logarithmic and not linear. The bigger thing most never mention is antenna radiation pattern if the antenna is not tuned to resonance...which can be good or bad. A 5/8 wave vertical is non-resonant, but we know that length optimizes low-angle radiation towards the horizon compared to warming the clouds. However, when we move away from a perfectly resonant dipole, energy is not lost but rather takes the form of lobes and nulls. This causes the antenna to behave in unpredicted ways and to me, this is a larger issue than arguing about power loss due to an antenna tuner or SWR. 73
"and at the end of the day, it doesn't really matter as long as the transmission line is of good quality and the mismatch is not significant to cause significant loss of power due to heat in the transmission line" 100%, great post... Thank you!
@Pioneer936 your statement is true in a perfect world. Coax and transmission line loss increases with mismatch. Energy is not conserved, it is lost in the feedline. The part about measuring power is also more important...a 50 ohm power meter will not work properly if the system is mismatched.
@daveN2MXX all power that is reflected is conserved, its not lost because of the mismatch, the only loss is because of the feed line not swr ,a 10,1 swr doesn't means that nearly 70% of the power is lost it can be as little as 3% ,the other guy states this in his videos
@daveN2MXX also just because an antenna is not resonant doesn't necessarily mean that the radiation efficiency drops, the antenna can be reduced to 25% of its original length before radiation patterns become of significance to pattern changes
If you make a ground plane, lets say out of wire and cant raise it high enough to slope the radials down to around 30 degrees to achieve 50 ohms. like an 80m or 40m vertical. It will read around 30 ohms. feeding it with 75 ohm coax (especially 1/2 WL long multiples) will give you a nice 50 ohm match. some of us cant live with 1.5/1
In the video Standing Up For Standing Waves (search TH-cam) Bill Hays starts with the idea that all an antenna tuner does is make your transmitter happy, which many in his audience (members of a repeater club) agreed with. He then showed (not told) them that what it really does is make the antenna happy. He made a point: you don't care about your transmitter,as long as it's putting out full power and not getting hot, you care about the other guy's receiver. Adding a conjugal match somewhere between the transmitter and the antenna caused the latter to radiate at virtually full power.
Bill did a great job in that video
Word salad to justify a common misunderstanding. Matching networks (essentially the same circuit hams call an antenna tuner) are tuning AM broadcast towers all over the world every day to resonate at the station's operating frequency. How do they think WLW gets their 5/8 wave tower to work? Used properly, it WILL tune the antenna!
Nah, its a matching network
@@CoffeeandHamRadios I think you have a basic misunderstanding of conjugate match. When you add reactance to an antenna circuit, which occurs when "j" is not 0, you change its resonant frequency. I have worked at many AM stations whose towers are not the correct height to be naturally resonant at the operating frequency. They are tuned to electrical resonance by the conjugate match, typically using a Pi network. Antenna tuners are so called because, by adding reactance, they change an antenna's resonant frequency.
Totally agree, where we deviate is that you say this is tuning the antenna and I say it is matching.
@@CoffeeandHamRadios How do you define "tuning" and why do you believe an antenna tuner does NOT do it?
@@CoffeeandHamRadios Here's what I think is the issue. You are looking at the antenna and the matching network as separate pieces. Let's say you have an antenna which is not naturally resonant at the carrier frequency. It is connected to the transmitter by a properly adjusted matching network. What is happening? You place an Operating Impedance Bridge between the matching network and antenna and see the complex impedance, with a reactive component, since the antenna is not naturally resonant at the carrier frequency. Place the OIB between the transmitter and the matching network and you see 50+j0, resonant at the carrier frequency. The matching network has matched the transmitter to the antenna, just as you say.
But what about resonance? In a resonant circuit, the electric current oscillates at its resonant frequency. An antenna has a natural resonant frequency because of its length and the speed of electric propagation along its length. But, in the example above, at what frequency is the antenna current oscillating? It is oscillating, not at the antenna's natural resonant frequency, because the current is oscillating through the conjugate matching network as well as the antenna. Nowhere in the system, not in the antenna nor in the matching network, is current oscillating at the antenna's natural resonant frequency.
This is why we say that the conjugate match has tuned the antenna to a new resonant frequency. So, a conjugate matching network can properly be called an antenna tuner because it does tune the antenna's resonant frequency.
The way i understand conjugate match between the antenna and tuner is that the the antenna feedpoint is equal and opposite in phase with the tuner output, wouldn't that make the antenna feedpoint resonant, is this why Maxwell constantly refers to the antenna as being tuned to resonant in his books ?
The reflected power being in phase with the forward power would then add to it ,its not creating more power rather conserving the original power put into the system, obviously in real world applications there will be some loss within the feedline which may or maynit be an issue depending on frequency, main point being the tuner is helping the transmitter to produce its maximum power into the system without causing damage to transmitter
This is exactly what I was trying to convey. But the ATU doesn't change a single characteristic of the antenna, right? If you tune a piano or a guitar you change the wire right?
@@CoffeeandHamRadios you can't compare a musical instrument with an antenna, a musical instrument must be resonant to make the note you require an antenna doesn't need to be resonant to radiate efficiently,
If the conjugate match is present between the tuner and antenna feedpoint there must be resonance there also ,therefore with the feedpoint being resonant then the antenna is surely, if there's no conjugate match between tuner and antenna then there's no power transfer and you tuner would heat up
I wasn't comparing the antenna to a musical instrument, I was discussing that act of tuning...
@@CoffeeandHamRadios think your sticking point is what the conjugate match is doing between tuner and antenna
No, I fully understand what is happening. I think we agree on what is taking place but you want to say "it's tuning the antenna" and I disagree and I think it's matching impedance, the antenna itself isn't being tuned. It really doesn't matter to me what language we use to describe the exact same process... for some reason it seems to matter to you.
Your method and analysis are right on. With low loss, tuning at the rig end also presents a good match to the antenna. This can be shown using Smith Charts, either paper or computer aided, or using Dean Straw's TLW program which comes with the ARRL antenna book. It can also be shown experimentally by putting 50 ohms on the transmitter side of the tuner and looking back down the coax towards the tuner, and comparing the measured complex Z and the complex Z of the antenna. They will be nearly conjugates of each other.
This understanding is what can be proven and should be understood by all parties. One should also understand that as losses in either the tuner or the line increase, the ability of the tuner to provide this conjugate match to the antenna is compromised, although it still works to some extent. All the rest is just definitions, like where does the antenna stop and the "not antenna" (coax, etc) start. Before we can answer "does the tuner tune the antenna" we have to have agreement on the terms "tune" and "antenna" and that is where the discussion goes into unproductive areas.
Great comment John, thank you for adding to the conversation! ~Ape
Could adding and subtracting capacitance to create resonance be classed as tuning
Could the feedline be acting as an extension lead for the antenna feedpoint
Ape, you are going to make The Florida Ham Man go nuts.😊
👀
I hope so ki4ytv
I think FHM deletes all comments that don't agree with him
I try not to get too wrapped up in the theory and terminology. I have no issue using a tuner if necessary. At the end of the day, if I can make contacts and my transceiver is happy, all is well with me.
I think its a holy war where people just try to one up each other. There seems to be a group that likes to troll antenna tuner videos specifically looking to argue...
It's called Ham OCD.
If you use balanced line instead of coax the tuner and feed line will be part of your antenna system
Agreed
In the old days the tuner was actually in the transmitter. It was called a pi network. I don’t recall any hams or engineers I knew saying the coax had to be half wave long. I think maybe that was a CB myth. Today the tuner at the transmitter does the same thing it matches the fixed 50 ohm output of the new rigs to whatever is at the transmitter end of the coax. The feedline to antenna mismatch remains the same. The power ( let’s say 100 watts) is delivered from the transmitter into the feedline. In its travel from the transmitter to the antenna it is attenuated some amount. That’s the inherent loss of the coax. Let’s say it’s 3dB ( easy number to work with). Half of that 100 watts is lost in the coax. So 50 watts reaches the antenna. With a perfect match almost the complete 50 is radiated. However with a 2:1 SWR there will be voltage and current reflections. Reverse power or reflected power it’s sometimes called. So some power gets radiated but some is reflected. In the case of a 2:1 SWR that’s about 5 watts reflected. Of that 5 watts only about 2.5 gets back to the transmitter. ( 3dB loss in the cable). Essentially that 2.5 watts gets reflected back to the antenna. Again half of that is lost so only 1.5 watts makes it to the antenna, where 10% or .15 watts are reflected and half of that ( 0.075 watts) is lost on the return trip. Let’s stop here. Total loss in the feedline with the matched antenna was 50 watts. With the 2:1 SWR the loss was the sum of the losses first 50 watts, then 2.5 watts and then 1.5 watts. Total loss for the 2:1 SWR case was 50+2.5+ 1.5 equals 54 watts in our truncated example. The loss in the matched case was 50 due to coax loss. In the 2:1 case the loss increased by 4 watts. In dB that’s 3 dB loss for the matched case and less than 3.4 dB loss for the 2:1 SWR case.
There are charts in all the antenna books that will give you the additional loss in coax due to SWR. That is based on the inherent or matched loss of that coax. The higher the coax loss the higher the loss due to SWR. Of course all this is based on the proper match at the transmitter end to allow the transmitter to supply power to the antenna system and to cause a 100% reflection of any reflected power back toward the antenna. The tuner may not actually tune the antenna, obviously it does not create a match between the coax and the antenna, but it does create a situation where the transmitter can deliver rated power into the coax where it can all be used up either as heat in the coax ( be it one trip or many trips bouncing back and forth) or eventually radiated.
Each installation is different and loss needs to be evaluated and a determination made as to how much loss is acceptable. Also the transmitter end of the coax needs to be matched somehow so that all power reflected from the antenna terminals that makes it back to the transmitter is reflected back towards the antenna where it can either be attenuated in the coax or radiated by the antenna.
So does the tuner tune the antenna? Depends on what you mean by tune! It does not match the coax to the antenna. I think it does set up a resonant condition. Is that tuning the antenna? Maybe….
@dandypoint
Your comments are helpful but need one clarification. It is very true that definitions are what are the main dividing point in this argument, and so I would mention one thing. When you say "obviously it does not create a match between the coax and the antenna" you very likely mean that the tuner does not create a match between the Zo of the coax (typically 50 ohms) and the Z looking into the antenna, in your example either 25 or 100 ohms. The tuner changes nothing about the antenna itself, and also nothing about the Zo of the line, so it is indeed obvious those ratios are unchanged. Those ratios determine the actual value of SWR on the line, so that also is unchanged.
But the tuner does change the Z looking towards the transmitter/receiver as seen by the antenna. In the 100 ohm case, the Z the antenna sees looking into the coax is not 50 ohms, but something closer to 100 ohms as a result of the tuner. An example I did with a particular coax and length to get 3 dB loss gave 64 + j11.3. This was calculated with the TLW program that comes with the antenna book using 20.5 meters of RG-174 at 14 MHz. This represents an SWR seen by the antenna of 1.6:1. A 50 ohm load at the transmitter end but without the tuner, the SWR for the antenna looking into the line would be 2:1, So in this rather lossy case, the tuner only partly matches the antenna to the line. (2:1 down to 1.6:1) If the above calculations are done with a 1 dB line, the antenna to coax conjugate match is much better. With a lossless tuner and a lossless line, the antenna sees looking into the 50 ohm line will be its exact complex conjugate. This is the point of this whole video.
@@JohnStanley-m3t yes. The ideal is to have the coax see an impedance of 50 + j0 ohms. When it does not it becomes an impedance transformer. Transforming the antenna Z to some other R and X at the transmitter end depending on transmission line characteristics and length. Then you accept the loss on the line due to using that particular line plus the additional loss due to SWR. The additional loss may be very small if the coax has low loss to start with. Then the tuner needs to get the power into the coax. That used to be in the transmitter itself and now it’s usually in a separate box called a tuner. Sounds like you have a good handle on it. I was trying to ahead some additional light on the subject from the perspective of an old time ham plus EE. That’s hard to do sometimes.
I don't use an antenna tuner. As a matter of fact I don't even use an antenna, I just hang the coax out the window and let the free wind take the signal.
If it works it works 🍻
Maxwell's stuff is a lot like the bible, the words mean what they mean, but people's misinterpretation of them is where the issues arise.......
I like this...
It's definitely some kinda misunderstanding of Maxwells terminology ,
what does he mean when he states the antenna feedpoint impedance is tuned by the output of the feedline which is the conjugate of the tuner output,
I see that as the feedline has a conjugate match between the tuner and the antenna feedpoint therefore being that the reactance has been cancelled out at the antenna feedpoint creating a resonant feedpoint therefore a resonant antenna
Is this not the interpretation of others?
@Pioneer936 the best explanation I've seen recently was in a Facebook antenna group, by Tom, W8JI.
His explanation made the most sense to me of any I read. It doesn't jive with what is said in these videos either, and that's because he understands what Maxwell meant, and most of us(including these videos) don't. The signal doesn't bounce back and forth, and eventually decide to exit the antenna. The wave is standing, just like it sounds like it is.
@@VE9ASN yes Tom had worked with Maxwell also ,I saw the post ,totally agree about standing waves standing
It is the understanding; bit like I have to keep replying to (over and over) is that is should like you are matching the antenna impedance not tuning the antenna. Call it whatever you want, it really doesn't matter. You seem to like claiming to have some secret that others simply don't understand.
Both sides of this argument are right to some extent, and both are wrong. Think about this: what is "power"? To calculate power, you must provide context of other variables: voltage, resistance, impedance, etc. This is one reason why high voltage electricity transmission lines are used. Most amateur radio power meters measure power in the context of a 50-ohm load. If the antenna (or antenna system) is not 50 ohms, then the power reading must be considered in that context. When that other guy says on his youtube channel that power is created when SWR is present, and then shows a "power meter" to prove his point, he is completely misunderstanding the context of a power measurement. Whether an antenna tuner actually tunes an antenna is also subject to context....and at the end of the day, it doesn't really matter as long as the transmission line is of good quality and the mismatch is not significant to cause significant loss of power due to heat in the transmission line. "Significant" is also subjective, since radiated signal effectiveness is logarithmic and not linear. The bigger thing most never mention is antenna radiation pattern if the antenna is not tuned to resonance...which can be good or bad. A 5/8 wave vertical is non-resonant, but we know that length optimizes low-angle radiation towards the horizon compared to warming the clouds. However, when we move away from a perfectly resonant dipole, energy is not lost but rather takes the form of lobes and nulls. This causes the antenna to behave in unpredicted ways and to me, this is a larger issue than arguing about power loss due to an antenna tuner or SWR. 73
"and at the end of the day, it doesn't really matter as long as the transmission line is of good quality and the mismatch is not significant to cause significant loss of power due to heat in the transmission line" 100%, great post... Thank you!
He doesn't state power is created he states power is conserved and adds to the forward power he is correct
@Pioneer936 your statement is true in a perfect world. Coax and transmission line loss increases with mismatch. Energy is not conserved, it is lost in the feedline. The part about measuring power is also more important...a 50 ohm power meter will not work properly if the system is mismatched.
@daveN2MXX all power that is reflected is conserved, its not lost because of the mismatch, the only loss is because of the feed line not swr ,a 10,1 swr doesn't means that nearly 70% of the power is lost it can be as little as 3% ,the other guy states this in his videos
@daveN2MXX also just because an antenna is not resonant doesn't necessarily mean that the radiation efficiency drops, the antenna can be reduced to 25% of its original length before radiation patterns become of significance to pattern changes
"Antenna Tuner" should be declared foul language and XXX rated.
This is probably true...
Man, if I can't get it to tune, I'll just bust out the rg11
75ohmLyFE
If you make a ground plane, lets say out of wire and cant raise it high enough to slope the radials down to around 30 degrees to achieve 50 ohms. like an 80m or 40m vertical. It will read around 30 ohms. feeding it with 75 ohm coax (especially 1/2 WL long multiples) will give you a nice 50 ohm match. some of us cant live with 1.5/1