This explanation makes perfect sense. While attending tech school and the study of an AC signal with inductors and capacitors. I learned that in an inductor the voltage across it was higher as shown on a dual channel OScope when the magnetic field of the inductor colapsed as the AC signal changed transistion. And while this applied to AC, it has a direct correlation to radio signals.
Always great stuff Mark! Not sure why some hams (and YT "content creators") can't seem to get this right - it's not THAT complicated. They continue to refuse to accept the simple truths. Anyway, keep the message coming! 73 from west Texas, ~Alan W5ARM
And once you understand it, it's logical. The transmitter is cranking out full power with a 1:1 SWR into the tuner. So full power output MUST be absorbed by the antenna!
This is all horribly misunderstood, particularly on internet forums. Unfortunately some big YT channels get this all wrong too, at least ARRL publications are subject to some peer review.
Does this conjugate match concept also apply to signals with reflections that don't necessarily have trans-match networks? I have my IC-705, which doesn't have a built-in tuner, and on 20m my SWR is 2:1 at 14.385 MHz . Does this mean that roughly 11% of my power is reflected back to the radio and is absorbed by it? The way I understand it, that no tuner is needed and as long as I am transmitting, reflected power bounces back to the antenna in-phase with the incident wave and transforms into reflection gain? And that I only need a tuner if I am getting close to a threshold of the SWR values ( that a particular radio was designed for) where protection circuits may start kicking in cutting my power? So, as long as my 705 is within the SWR range at which I get my full 10W out to the antenna I shouldn't worry too much. Am I wrong? Does this only apply if one has a tuner? On 14.385 MHz my SWR is 2:1, according to my Nano-VNA. I also measured my coax feed line loss when perfectly matched on 20m at 14.385 : -0.31dB. In the ARRL Antenna Book I looked up additional loss due to SWR of 2:1 : - 0.15dB. This brings the total loss in my transmission line system to - 0,46dB. Ludicrous!!!! Who, in their right mind, would worry about a 1/12 of an S unit? Half a dB is imperceptible for even a professional studio audio/mix engineer listening through high end monitors in an acoustically treated room and no noise floor. But on HF no one would tell a difference between S7 and S8 with average noise floor levels. And that's 6 dBs! But perhaps, this is only true with tuners? What if I don't want one? Because if this works the same without a tuner, I don't need it just to get my 1/12 of an S-unit back...
Reflected power is NOT absorbed by the transmitter, tuner or no tuner. Here's what happens with no tuner. Say you have a transmitter putting out 100 watts but 50 watts is reflected back. The transmitter output will be reduced to 50 watts and that 50 watts combines with the reflected power of 50 watts, so 100 watts is still delivered to the antenna. There is no loss. In your case with a 2:1 SWR, that's about where protection circuits click in and reduce power to protect the finals. But they are not protecting the finals from reflected power. They protect the finals from the impedance mismatch which can cause excessive voltage and current in the final states, cooking the transistors. Remember, the transistor is the fastest fuse on three legs. I personally am not comfortable with a 2:1 SWR with no tuner. Transceiver's are expensive to repair. For more reading download a series of articles from Palomar Engineering called "Kurt Speaks Out," page 12 under "Reflected Power Revisited."
@@NoMoreRadioMyths not sure what they thinking aren't reference books there for referring to ,another one they try is that you have misunderstood what has been written how ironic
I see "reflection gain" on my outboard power meter all the time, indicating I'm outputting at or above the rated output of the transmitter. Encouraging that my relatively low power is not lost!
This is a hard topic for lot of people to grasp. Everyone wants to apply simple equations. We have here R and X or I should say R+jX. This is called a complex number in math! Sometimes the term jX is called imaginary! All for good reason. When using only real resistances things are fairly easy to see but we are dealing most of the time with not only resistance but reactance. There is a phase shift involved and the current is not always in phase with the voltage. Power is not just voltage times current but it is voltage times current times the cosine of the angle in between. Lots of times the cosine factor is simply 1 and not spoken about. We know the real forward power has the voltage and current in phase but when reflections occur and direction reverses and standing waves appear because forward and reflected voltages and currents add and subtract all along the line, it gets complicated pretty quick! Keep up the good videos!
Thank you for this info and your other videos on similar topics. Really opened this newer hams eyes to experiment with non resonant antennas. Has been a game changer for me.
@wesh1061 Don't believe the baloney that a resonant antenna is better. As long as an antenna is long enough for whatever frequency it'll work just fine.
How good are you at identifying interference? Not the place for this but I don't know how to contact you otherwise. Have you ever heard this kind of interfere and do you have any idea what could cause this ticking noise? It's consistent, 24/7, and I can't seem to locate the problem. Thanks in advance. ua-cam.com/video/i2yPeg0yOx0/v-deo.htmlfeature=shared Its only on my HF base at 6m and below but not on my UHF/VHF HTs or Mobile Car UHF/VHF base. I ruled out a problem with the HF base station, so its something in the area around it. I do have a HT with some hacked firmware that can receive HF, and its there as well, so its something causing interface on the HF frequencies (all of them!) If anyone has any ideas thank you in advance. I've shut down most of the stuff in the room including the wifi. No dice.
This explanation makes perfect sense. While attending tech school and the study of an AC signal with inductors and capacitors. I learned that in an inductor the voltage across it was higher as shown on a dual channel OScope when the magnetic field of the inductor colapsed as the AC signal changed transistion. And while this applied to AC, it has a direct correlation to radio signals.
We need thesmokingape to host a round table with Mark the Ham Florida Man and K8BYP..
Always great stuff Mark!
Not sure why some hams (and YT "content creators") can't seem to get this right - it's not THAT complicated. They continue to refuse to accept the simple truths.
Anyway, keep the message coming!
73 from west Texas,
~Alan
W5ARM
And once you understand it, it's logical. The transmitter is cranking out full power with a 1:1 SWR into the tuner. So full power output MUST be absorbed by the antenna!
This is all horribly misunderstood, particularly on internet forums. Unfortunately some big YT channels get this all wrong too, at least ARRL publications are subject to some peer review.
Does this conjugate match concept also apply to signals with reflections that don't necessarily have trans-match networks? I have my IC-705, which doesn't have a built-in tuner, and on 20m my SWR is 2:1 at 14.385 MHz . Does this mean that roughly 11% of my power is reflected back to the radio and is absorbed by it?
The way I understand it, that no tuner is needed and as long as I am transmitting, reflected power bounces back to the antenna in-phase with the incident wave and transforms into reflection gain? And that I only need a tuner if I am getting close to a threshold of the SWR values ( that a particular radio was designed for) where protection circuits may start kicking in cutting my power? So, as long as my 705 is within the SWR range at which I get my full 10W out to the antenna I shouldn't worry too much. Am I wrong? Does this only apply if one has a tuner?
On 14.385 MHz my SWR is 2:1, according to my Nano-VNA. I also measured my coax feed line loss when perfectly matched on 20m at 14.385 : -0.31dB. In the ARRL Antenna Book I looked up additional loss due to SWR of 2:1 : - 0.15dB. This brings the total loss in my transmission line system to - 0,46dB. Ludicrous!!!! Who, in their right mind, would worry about a 1/12 of an S unit? Half a dB is imperceptible for even a professional studio audio/mix engineer listening through high end monitors in an acoustically treated room and no noise floor. But on HF no one would tell a difference between S7 and S8 with average noise floor levels. And that's 6 dBs!
But perhaps, this is only true with tuners? What if I don't want one? Because if this works the same without a tuner, I don't need it just to get my 1/12 of an S-unit back...
Reflected power is NOT absorbed by the transmitter, tuner or no tuner. Here's what happens with no tuner. Say you have a transmitter putting out 100 watts but 50 watts is reflected back. The transmitter output will be reduced to 50 watts and that 50 watts combines with the reflected power of 50 watts, so 100 watts is still delivered to the antenna. There is no loss.
In your case with a 2:1 SWR, that's about where protection circuits click in and reduce power to protect the finals. But they are not protecting the finals from reflected power. They protect the finals from the impedance mismatch which can cause excessive voltage and current in the final states, cooking the transistors. Remember, the transistor is the fastest fuse on three legs.
I personally am not comfortable with a 2:1 SWR with no tuner. Transceiver's are expensive to repair.
For more reading download a series of articles from Palomar Engineering called "Kurt Speaks Out," page 12 under "Reflected Power Revisited."
@@NoMoreRadioMyths Thanks for taking the time to reply and provide the explanation
Another good explanation ,some try to ridicule those that read these books with this information, is it because they can't comprehend the content?
What do they think they are doing - making up their own laws of physics?
@@NoMoreRadioMyths not sure what they thinking aren't reference books there for referring to ,another one they try is that you have misunderstood what has been written how ironic
I see "reflection gain" on my outboard power meter all the time, indicating I'm outputting at or above the rated output of the transmitter. Encouraging that my relatively low power is not lost!
Love this subject, Useful information. Thank You
Glad it was helpful!
you sir got a new subscriber, great no frill videos strait to the point. love it
Love it! Thank you very much for covering this subject in depth. 73 de N4AAJ
My pleasure!
This is a hard topic for lot of people to grasp. Everyone wants to apply simple equations. We have here R and X or I should say R+jX. This is called a complex number in math! Sometimes the term jX is called imaginary! All for good reason. When using only real resistances things are fairly easy to see but we are dealing most of the time with not only resistance but reactance. There is a phase shift involved and the current is not always in phase with the voltage. Power is not just voltage times current but it is voltage times current times the cosine of the angle in between. Lots of times the cosine factor is simply 1 and not spoken about. We know the real forward power has the voltage and current in phase but when reflections occur and direction reverses and standing waves appear because forward and reflected voltages and currents add and subtract all along the line, it gets complicated pretty quick!
Keep up the good videos!
Great explanation you sound like an engineer. Yes, it's all difficult to wrap your head around especially when you've believed otherwise.
Thank you for this info and your other videos on similar topics. Really opened this newer hams eyes to experiment with non resonant antennas. Has been a game changer for me.
@@NoMoreRadioMyths yes. EE (Electronics) from Virginia Tech.
@wesh1061 Don't believe the baloney that a resonant antenna is better. As long as an antenna is long enough for whatever frequency it'll work just fine.
Is always longer antenna better? What is the most important to make efficient antenna?
Thank you for the video. Ki7RJS😁
How good are you at identifying interference?
Not the place for this but I don't know how to contact you otherwise. Have you ever heard this kind of interfere and do you have any idea what could cause this ticking noise? It's consistent, 24/7, and I can't seem to locate the problem. Thanks in advance.
ua-cam.com/video/i2yPeg0yOx0/v-deo.htmlfeature=shared
Its only on my HF base at 6m and below but not on my UHF/VHF HTs or Mobile Car UHF/VHF base. I ruled out a problem with the HF base station, so its something in the area around it. I do have a HT with some hacked firmware that can receive HF, and its there as well, so its something causing interface on the HF frequencies (all of them!)
If anyone has any ideas thank you in advance. I've shut down most of the stuff in the room including the wifi. No dice.
I see you figured it out. Good work!