Out of all the videos on TH-cam I've watched and all the articles I've read on the subject, the clearest explanation is this 50 year old short out of Canada. Thank you.
Same here. I were looking for an explanation of antennas everywhere and all I could find was kindergarten level explanations and advanced university stuff.
Oh my gosh. That was one of the most informative and well illustrated videos I have seen on radio waves on youtube. The old school videos are doing it right
Great video! One of the few videos, perhaps only, that shows the actual movement of electrons and explains advanced concepts conceptually. The viewer gains a true, intuitive understanding of the subject. Excellent!
You know why this video is so effective? The narrator pauses between explanations, it gives you time to think. Modern videos just want to cram as much content as possible, so they just transition very quickly.
Although it seems very very very old, it is very very very useful to me . Thanks. The E and H fields build and collapse 90 degrees out of phase with each other!!!
Great video, but there is one thing I don't quite understand. Maybe someone can help me out. If the current standing wave "H field" and the voltage standing wave "E field" are 90 degrees out of phase w/ each other (see from time 4:30), then how are the two waves that make up the propagating EM field both back in phase in time (see from time 5:45). Really trying to learn what all is going on here, can anyone help? Thanks.
Can someone explain why the E and H fields maximums are 90 out of phase of each other at the dipole in the near-field, but EM Waves have E and H peaks in phase as they radiate out in the far-field?
Dragos Minea ofeyofey I hope you both are fine. I think I can explain that. For example, in the infinitesimal dipole analysis, when you acquire the H and E fields, the E field has two components (radial and polar) and H field has only one component (azimuthal ), in the Near-Field-Region you take the two fields (H and E) and you make an approximation (kr1) and that eliminates the radial E field component, and only remains the polar component from E and the azimuthal component of H, also, both Fields become IN phase and the cross product of E and H is in the radial direction which is the Poynting's Vector direction (power radiated). I hope you both understand. Saludos!
@@redknight344 it's been a while, but the one question I've never gotten a clear answer to is how the E&H fields go from 90 degrees out of phase at first (4:35), only to end up in phase later (5:45). This doesn't make sense.
@@ThatEEguy2818 The EM field consist of two parts the reactive field and the radiation field in the near field region the reactive one is prominent and this is 90 degrees out of phase but in the far field region the radiation one is promiment and this is in phase. but in the two regions both always exist only that their strengh varies from region to region.
Here is a copy of my latest TOE, followed by the 'gravity' test that would recognize 'gravity' as being the force that makes the sine wave of em expand and contract and would act basically 90 degrees to the em forces, which of course act basically 90 degrees to each other. Revised TOE: 3/25/2017. My Current TOE: THE SETUP: 1. Modern science currently recognizes four forces of nature: The strong nuclear force, the weak nuclear force, gravity, and electromagnetism. 2. In school we are taught that with magnetism, opposite polarities attract and like polarities repel. But inside the arc of a large horseshoe magnet it's the other way around, like polarities attract and opposite polarities repel. (I have proved this to myself with magnets and anybody with a large horseshoe magnet and two smaller bar magnets can easily prove this to yourself too). 3. Charged particles have an associated magnetic field with them. 4. Protons and electrons are charged particles and have their associated magnetic fields with them. 5. Photons also have both an electric and a magnetic component to them. FOUR FORCES OF NATURE DOWN INTO TWO: 6. When an electron is in close proximity to the nucleus, it would basically generate a 360 degree spherical magnetic field. 7. Like charged protons would stick together inside of this magnetic field, while simultaneously repelling opposite charged electrons inside this magnetic field, while simultaneously attracting the opposite charged electrons across the inner portion of the electron's moving magnetic field. 8. There are probably no such thing as "gluons" in actual reality. 9. The strong nuclear force and the weak nuclear force are probably derivatives of the electro-magnetic field interactions between electrons and protons. 10. The nucleus is probably an electro-magnetic field boundary. 11. Quarks also supposedly have a charge to them and then would also most likely have electro-magnetic fields associated with them, possibly a different arrangement for each of the six different type of quarks. 12. The interactions between the quarks EM forces are how and why protons and neutrons formulate as well as how and why protons and neutrons stay inside of the nucleus and do not just pass through as neutrinos do. THE GEM FORCE INTERACTIONS AND QUANTA: 13. Personally, I currently believe that the directional force in photons is "gravity". It's the force that makes the sine wave of EM energy go from a wide (maximum extension) to a point (minimum extension) of a moving photon. When the EM gets to maximum extension, "gravity" flips and EM goes to minimum, then "gravity" flips and goes back to maximum, etc, etc. A stationary photon would pulse from it's maximum extension to a point possibly even too small to detect, then back to maximum, etc, etc. 14. I also believe that a pulsating singularity (which is basically a pulsating photon) is the energy unit in this universe. 15. When these pulsating energy units interact with other energy units, they tangle together. Various shapes (strings, spheres, whatever) might be formed, which then create sub-atomic material, atoms, molecules, and everything in existence in this universe. 16. When the energy units unite together they would tend to stabilize and vibrate. 17. I believe there is probably a Photonic Theory Of The Atomic Structure. 18. Everything is basically "light" (photons) in a universe entirely filled with "light" (photons). THE MAGNETIC FORCE SPECIFICALLY: 19. When the electron with it's associated magnetic field goes around the proton with it's associated magnetic field, internal and external energy oscillations are set up. 20. When more than one atom is involved, and these energy frequencies align, they add together, specifically the magnetic field frequency. 21. I currently believe that this is where a line of flux originates from, aligned magnetic field frequencies. NOTES: 22. The Earth can be looked at as being a massive singular interacting photon with it's magnetic field, electrical surface field, and gravity, all three photonic forces all being 90 degrees from each other. 23. The flat spiral galaxy can be looked at as being a massive singular interacting photon with it's magnetic fields on each side of the plane of matter, the electrical field along the plane of matter, and gravity being directed towards the galactic center's black hole where the gravitational forces would meet, all three photonic forces all being 90 degrees from each other. 24. As below in the singularity, as above in the galaxy and probably universe as well. 25. I believe there are only two forces of nature, Gravity and EM, (GEM). Due to the stability of the GEM with the energy unit, this is also why the forces of nature haven't evolved by now. Of which with the current theory of understanding, how come the forces of nature haven't evolved by now since the original conditions acting upon the singularity aren't acting upon them like they originally were, billions of years have supposedly elapsed, in a universe that continues to expand and cool, with energy that could not be created nor destroyed would be getting less and less dense? My theory would seem to make more sense if in fact it is really true. I really wonder if it is in fact really true. 26. And the universe would be expanding due to these pulsating and interacting energy units and would also allow galaxies to collide, of which, how could galaxies ever collide if they are all speeding away from each other like is currently taught? DISCLAIMER: 27. As I as well as all of humanity truly do not know what we do not know, the above certainly could be wrong. It would have to be proved or disproved to know for more certainty. -------------------------------------------------------------------------------------------------------------------------- Now the test for 'gravity': Here is the test for the 'gravity' portion of my TOE idea. I do not have the necessary resources to do the test but maybe you or someone else reading this does, will do the test, then tell the world what is found out either way. a. Imagine a 12 hour clock. b. Put a magnetic field across from the 3 to 9 o'clock positions. c. Put an electric field across from the 6 to 12 o'clock positions. (The magnetic field and electric field would be 90 degrees to each other and should be polarized so as to complement each other.) d. Shoot a high powered laser through the center of the clock at 90 degrees to the em fields. e. Do this with the em fields on and off. (The em fields could be varied in size, strength, density and depth. The intent would be to energy frequency match the laser and em fields for optimal results.) f. Look for any gravitational / anti-gravitational effects. (Including the utilization of ferro cells so as to be able to actually see the energy field movements.) (An alternative to the above would be to shoot 3 high powered lasers, or a single high powered laser split into 3 beams, each adjustable to achieve the above set up, all focused upon a single point in space.) 'If' effects are noted, 'then' further research could be done. 'If' effects are not noted, 'then' my latest TOE idea is wrong. But still, we would know what 'gravity' was not, which is still something in the scientific world. Science still wins either way and moves forward.
How do you reconcile the explanation at around 3:00 where the E-field is max when B-field zero, and vice versa, with the later statement that the traveling wave has the E and B fields in phase?
it seems they made a mistake in the video because they are really synchronized according to Mr. Maxwell :p en.wikipedia.org/wiki/Maxwell%27s_equations#/media/File:Electromagneticwave3D.gif
E & H fields are in time phase because both are at max value at the same time and at min value the same time E & H fields are in space ortogonal, thet is at 90 degrees to each other
This is not explained at all well. Electrons in motion create the magnetic field, whereas zero motion ( no current ) has no magnetic field. While the electrons begin travelling, from the time of zero voltage at the feed point, the magnetic field and electric field rise together and fall together as the feed voltage rises and fall in the sine wave. It may not seem intuitive that there is a changing current, because the wires are open circuit to normal DC voltage, however a voltage applied to any open unterminated cable pair will cause a current flow right up to the point where the electrons can travel no further. If the frequency of the changing voltage is such that the direction of electron flow (current) is reversed just as they reach the end of the wires you begin to have the makings of antenna theory. The speed of travel of the driving energy along the wires match with the length of the antenna wires in proportions related to the type of antenatal.
Current flow produces magnetic field. Polarity (accumulation of electrons on one side due to voltage) creates electric field. Now, the CHANGE in current direction produces a VARYING magnetic field which in-turn creates an electric field. and CHANGE in polarity (change in the side of accumulation of electrons) produces VARYING electric field which in-turn creates magnetic field. So, magnetic field is produced due to current in the antenna AND ALSO due to the change in electric field. and electric field is produced due to polarity in the antenna AND ALSO due to the change in magnetic field. Hence, both fields are produced at all times and these fields are perpendicular to each other. Hope this offers some clarity :)
Merci pour cette vidéo. Est-ce qu'un plan d'eau (bassin de rétention etc.) peut modifier la qualité de réception d'une antenne qui fait que de la réception? Et en particulier dans la gamme VLF?
Answer supplied by researchgate.net: The answer lies in the boundary conditions. the divergence of E field is rho/e0, that means something is coming out of the surface , depending on the surface the thing which is coming out will change or in other words the electric lines need a termination point so surface plays a role in it. Wheras the divergence of b is zero, so nothing is coming out so surface has no role to play, in other words magnetic field lines are closed and surface do not modulate them. I hope this answers your question.
Earlier in the video, we see that at a time, only one i.e. either electric and magnetic have their peaks (in electron flow pattern) but now during sign wave representation of the fields, both electric and magnetic fields have peaks at same time. How is this possible now?
H for "Half cycle" DOH! I've been trying to get through my ARRL book and that's been bugging me...maybe I missed it, and maybe I'm mixing things up, but now I can at least remember H :)
Why are magnetic field fluxes not even at any point in the wire? Because I remember that electricity is even at any given point. Why the edges of wire have smaller magnetic field lines and the center has greater line? Wasn't it supposed to be like a cylinder rising in diameter and collapsing, but diameter even at any given point ?
Great vedio, but i am a little puzzle about the amplitude of E plan and H plan, the 2 plan could not get the maximum value at the same time, there should be 90 degree phase difference, is this a typo?
No Mr 世鹏胡, they are with a 90° phase difference when they are in the "Near-Field-region" and there is no average power radiated , when the fields are in the "Far-Field-Region" they lose their 90° phase difference and now there is an non-zero average power radiated. I hope that answer your questions. Have a nice day.
Let me tell you my experience. All theories in RF transmission are good for classroom teaching. One has to practically do and learn in laboratory to understand antenna basics. I find huge differences between theory and practice. Infact I find certain things in books are entirely wrong or opposite. If it works it works because it works. Nothing works in deterministic way as the theory say. Simple things like material, conduction material, type of wire, grounding etc etc which makes huge difference in operation are conveniently neglected in books.
![SAFEPLANET - ดาวเคราะห์ [ THE PLANET ]](http://i.ytimg.com/vi/4X1XL3I_k3c/mqdefault.jpg)
I’m an antenna engineer but still like watching videos like this.
I have been waiting 25 years for this . Wonderful. Old is the best.
Thanks
Did you serve Canadian Armded force?
Same here. What a fantastic explanation
Out of all the videos on TH-cam I've watched and all the articles I've read on the subject, the clearest explanation is this 50 year old short out of Canada. Thank you.
Same here. I were looking for an explanation of antennas everywhere and all I could find was kindergarten level explanations and advanced university stuff.
Fantastic
It's good stuff eh? ;D
Literally this is the best thing I've ever found
Oh my gosh. That was one of the most informative and well illustrated videos I have seen on radio waves on youtube. The old school videos are doing it right
Thought this was going to be rubbish but it's the best video on the subject I've found! ✅
Great video! One of the few videos, perhaps only, that shows the actual movement of electrons and explains advanced concepts conceptually. The viewer gains a true, intuitive understanding of the subject. Excellent!
You know why this video is so effective? The narrator pauses between explanations, it gives you time to think. Modern videos just want to cram as much content as possible, so they just transition very quickly.
Best explanation of how antennas work I've ever seen. Why didn't I find this sooner?
Now I finally get what explains to me like a 5 year old, your videos just demystefied and cleared one hell of haze. This is the old is gold.
Gosh I love these old training and education films. My favorites are the Bell Science series. Thanks for posting this old relic!
the best video that i have seen, explanation upto the core, wow simple amazing
thanks a lot
This helped me tremendously.
I don’t know when I’ve seen so many positive comments on any video.
Geez I just wanted to know how to set up my TV antenna so I can watch the hockey playoffs. Now I want to go university.
Bost1 hi
Itll do that
😄
That is why they say old is gold. Very informative video
Very clear and interesting way of teaching a complex subject. Thanks a lot.
I felt much relieved after seeing this animation video describing antenna.... thank u so much for creating dis video!!!
I always know when I see a really old educational video (usually military) i'm going to learn something new.
Although it seems very very very old, it is very very very useful to me . Thanks.
The E and H fields build and collapse 90 degrees out of phase with each other!!!
Excellent video for understanding basics of EM-Propagation !!!
Thanks for your lecture. It's very clear and interesting way of teaching a complex subject 😍
Best explanation... Old is gold...
this is the best explanation that i never ever heard:-) short time but a lot!!!!! great job:-) thanks
Estos vídeos educativos de esa época parecen mejores que los de ahora.
Thank you for this great and simple to understand video!
Best explanation ... Much better than modern 3d explanations
Excellent video!! I have been confused by this problem for a long time!
Great video, but there is one thing I don't quite understand. Maybe someone can help me out. If the current standing wave "H field" and the voltage standing wave "E field" are 90 degrees out of phase w/ each other (see from time 4:30), then how are the two waves that make up the propagating EM field both back in phase in time (see from time 5:45). Really trying to learn what all is going on here, can anyone help? Thanks.
Damn they don't make them like this anymore...
Very conceptual...grt work
I can feel the electrons splashing on the cathode ray tube display that these guys are using for illustration
Can someone explain why the E and H fields maximums are 90 out of phase of each other at the dipole in the near-field, but EM Waves have E and H peaks in phase as they radiate out in the far-field?
Exactly what I don't understand also.
Dragos Minea ofeyofey I hope you both are fine.
I think I can explain that.
For example, in the infinitesimal dipole analysis, when you acquire the H and E fields, the E field has two components (radial and polar) and H field has only one component (azimuthal ), in the Near-Field-Region you take the two fields (H and E) and you make an approximation (kr1) and that eliminates the radial E field component, and only remains the polar component from E and the azimuthal component of H, also, both Fields become IN phase and the cross product of E and H is in the radial direction which is the Poynting's Vector direction (power radiated). I hope you both understand.
Saludos!
Edward Medina Guerra
Hi Thanks for the explanation. Would take a bit of reading to understand but thanks.
ofeyofey Hello, you're welcome. Have a nice day.
im a rf test engineer and this is a great video :) thanks for posting
Hi Leonard. Can I ask you a few questions about how this works?
@@ThatEEguy2818 which questions?
@@redknight344 it's been a while, but the one question I've never gotten a clear answer to is how the E&H fields go from 90 degrees out of phase at first (4:35), only to end up in phase later (5:45). This doesn't make sense.
@@ThatEEguy2818 The EM field consist of two parts the reactive field and the radiation field in the near field region the reactive one is prominent and this is 90 degrees out of phase but in the far field region the radiation one is promiment and this is in phase. but in the two regions both always exist only that their strengh varies from region to region.
@@redknight344 so how is the far field created?
I love old school, so simple without any stupid animations.
... and without an annoying and unnecessary music track under the voice.
Gracias por recordarme el conocimiento adquirido en la Escuela !
Slds desde Argentina 🇦🇷👋
This is good material, thanks
OMG, this is bloody awesome, any more releases you have, please tell.
Here is a copy of my latest TOE, followed by the 'gravity' test that would recognize 'gravity' as being the force that makes the sine wave of em expand and contract and would act basically 90 degrees to the em forces, which of course act basically 90 degrees to each other.
Revised TOE: 3/25/2017.
My Current TOE:
THE SETUP:
1. Modern science currently recognizes four forces of nature: The strong nuclear force, the weak nuclear force, gravity, and electromagnetism.
2. In school we are taught that with magnetism, opposite polarities attract and like polarities repel. But inside the arc of a large horseshoe magnet it's the other way around, like polarities attract and opposite polarities repel. (I have proved this to myself with magnets and anybody with a large horseshoe magnet and two smaller bar magnets can easily prove this to yourself too).
3. Charged particles have an associated magnetic field with them.
4. Protons and electrons are charged particles and have their associated magnetic fields with them.
5. Photons also have both an electric and a magnetic component to them.
FOUR FORCES OF NATURE DOWN INTO TWO:
6. When an electron is in close proximity to the nucleus, it would basically generate a 360 degree spherical magnetic field.
7. Like charged protons would stick together inside of this magnetic field, while simultaneously repelling opposite charged electrons inside this magnetic field, while simultaneously attracting the opposite charged electrons across the inner portion of the electron's moving magnetic field.
8. There are probably no such thing as "gluons" in actual reality.
9. The strong nuclear force and the weak nuclear force are probably derivatives of the electro-magnetic field interactions between electrons and protons.
10. The nucleus is probably an electro-magnetic field boundary.
11. Quarks also supposedly have a charge to them and then would also most likely have electro-magnetic fields associated with them, possibly a different arrangement for each of the six different type of quarks.
12. The interactions between the quarks EM forces are how and why protons and neutrons formulate as well as how and why protons and neutrons stay inside of the nucleus and do not just pass through as neutrinos do.
THE GEM FORCE INTERACTIONS AND QUANTA:
13. Personally, I currently believe that the directional force in photons is "gravity". It's the force that makes the sine wave of EM energy go from a wide (maximum extension) to a point (minimum extension) of a moving photon. When the EM gets to maximum extension, "gravity" flips and EM goes to minimum, then "gravity" flips and goes back to maximum, etc, etc. A stationary photon would pulse from it's maximum extension to a point possibly even too small to detect, then back to maximum, etc, etc.
14. I also believe that a pulsating singularity (which is basically a pulsating photon) is the energy unit in this universe.
15. When these pulsating energy units interact with other energy units, they tangle together. Various shapes (strings, spheres, whatever) might be formed, which then create sub-atomic material, atoms, molecules, and everything in existence in this universe.
16. When the energy units unite together they would tend to stabilize and vibrate.
17. I believe there is probably a Photonic Theory Of The Atomic Structure.
18. Everything is basically "light" (photons) in a universe entirely filled with "light" (photons).
THE MAGNETIC FORCE SPECIFICALLY:
19. When the electron with it's associated magnetic field goes around the proton with it's associated magnetic field, internal and external energy oscillations are set up.
20. When more than one atom is involved, and these energy frequencies align, they add together, specifically the magnetic field frequency.
21. I currently believe that this is where a line of flux originates from, aligned magnetic field frequencies.
NOTES:
22. The Earth can be looked at as being a massive singular interacting photon with it's magnetic field, electrical surface field, and gravity, all three photonic forces all being 90 degrees from each other.
23. The flat spiral galaxy can be looked at as being a massive singular interacting photon with it's magnetic fields on each side of the plane of matter, the electrical field along the plane of matter, and gravity being directed towards the galactic center's black hole where the gravitational forces would meet, all three photonic forces all being 90 degrees from each other.
24. As below in the singularity, as above in the galaxy and probably universe as well.
25. I believe there are only two forces of nature, Gravity and EM, (GEM). Due to the stability of the GEM with the energy unit, this is also why the forces of nature haven't evolved by now. Of which with the current theory of understanding, how come the forces of nature haven't evolved by now since the original conditions acting upon the singularity aren't acting upon them like they originally were, billions of years have supposedly elapsed, in a universe that continues to expand and cool, with energy that could not be created nor destroyed would be getting less and less dense? My theory would seem to make more sense if in fact it is really true. I really wonder if it is in fact really true.
26. And the universe would be expanding due to these pulsating and interacting energy units and would also allow galaxies to collide, of which, how could galaxies ever collide if they are all speeding away from each other like is currently taught?
DISCLAIMER:
27. As I as well as all of humanity truly do not know what we do not know, the above certainly could be wrong. It would have to be proved or disproved to know for more certainty.
--------------------------------------------------------------------------------------------------------------------------
Now the test for 'gravity':
Here is the test for the 'gravity' portion of my TOE idea. I do not have the necessary resources to do the test but maybe you or someone else reading this does, will do the test, then tell the world what is found out either way.
a. Imagine a 12 hour clock.
b. Put a magnetic field across from the 3 to 9 o'clock positions.
c. Put an electric field across from the 6 to 12 o'clock positions.
(The magnetic field and electric field would be 90 degrees to each other and should be polarized so as to complement each other.)
d. Shoot a high powered laser through the center of the clock at 90 degrees to the em fields.
e. Do this with the em fields on and off.
(The em fields could be varied in size, strength, density and depth. The intent would be to energy frequency match the laser and em fields for optimal results.)
f. Look for any gravitational / anti-gravitational effects.
(Including the utilization of ferro cells so as to be able to actually see the energy field movements.)
(An alternative to the above would be to shoot 3 high powered lasers, or a single high powered laser split into 3 beams, each adjustable to achieve the above set up, all focused upon a single point in space.)
'If' effects are noted, 'then' further research could be done.
'If' effects are not noted, 'then' my latest TOE idea is wrong. But still, we would know what 'gravity' was not, which is still something in the scientific world. Science still wins either way and moves forward.
Fantastic explanation. Superb
When the E field is maximum, H field is zero and vice versa as shown in the animation at 04:20. Then at 05:47 How come the peaks occur simultaneously?
How do you reconcile the explanation at around 3:00 where the E-field is max when B-field zero, and vice versa, with the later statement that the traveling wave has the E and B fields in phase?
Same question in my head?
how did they make this video? did they use an 8 bit computer to create these CGIs?
reeglyson escabal i asked my self the same question !! its amazing in that time to do this vedio
Probably done with drawings and stop motion photography
NARRATED IN AN UNDERSTANDABLE WAY
Tanks a lot for posting, helps me and more important helps newbe hams im trying to explain!
73's de PA2KGF
How the E and H fields appear in time phase in the pattern? They are out of time phase (90 deg) at the begging of the video ...
Thank you! I've been struggling with this part too
it seems they made a mistake in the video because they are really synchronized according to Mr. Maxwell :p en.wikipedia.org/wiki/Maxwell%27s_equations#/media/File:Electromagneticwave3D.gif
E & H fields are in time phase because both are at max value at the same time and at min value the same time
E & H fields are in space ortogonal, thet is at 90 degrees to each other
This is not explained at all well. Electrons in motion create the magnetic field, whereas zero motion ( no current ) has no magnetic field. While the electrons begin travelling, from the time of zero voltage at the feed point, the magnetic field and electric field rise together and fall together as the feed voltage rises and fall in the sine wave. It may not seem intuitive that there is a changing current, because the wires are open circuit to normal DC voltage, however a voltage applied to any open unterminated cable pair will cause a current flow right up to the point where the electrons can travel no further. If the frequency of the changing voltage is such that the direction of electron flow (current) is reversed just as they reach the end of the wires you begin to have the makings of antenna theory. The speed of travel of the driving energy along the wires match with the length of the antenna wires in proportions related to the type of antenatal.
Current flow produces magnetic field.
Polarity (accumulation of electrons on one side due to voltage) creates electric field.
Now, the CHANGE in current direction produces a VARYING magnetic field which in-turn creates an electric field.
and CHANGE in polarity (change in the side of accumulation of electrons) produces VARYING electric field which in-turn creates magnetic field.
So, magnetic field is produced due to current in the antenna AND ALSO due to the change in electric field.
and electric field is produced due to polarity in the antenna AND ALSO due to the change in magnetic field.
Hence, both fields are produced at all times and these fields are perpendicular to each other.
Hope this offers some clarity :)
Merci pour cette vidéo. Est-ce qu'un plan d'eau (bassin de rétention etc.) peut modifier la qualité de réception d'une antenne qui fait que de la réception? Et en particulier dans la gamme VLF?
how did you know i wanted a video on wave propagation?
it is really very good video to understand the concept of antenna. Is it possible to use this video for educational purpose.
Excellent explanation - where do you get this stuff?
Thanks for putting this up .
With the beginning of this video, I thought it was Monty Python LOL.
thankyou..... wht a gret expalanion which i never seen before
Hi Javier, I was wondering if you knew the date this video was made? Im doing a presentation on animation in the 1950s and would like to use it.
This is VERY informative.
Excelent explanation!
If H and E are out of phase by 90 deg, then how are the peaks occurring simultaneously at around 5:30 in the video?
Why isn't the H-field changed by the surface? Does anybody care to explain?
Answer supplied by researchgate.net: The answer lies in the boundary conditions. the divergence of E field is rho/e0, that means something is coming out of the surface , depending on the surface the thing which is coming out will change or in other words the electric lines need a termination point so surface plays a role in it. Wheras the divergence of b is zero, so nothing is coming out so surface has no role to play, in other words magnetic field lines are closed and surface do not modulate them. I hope this answers your question.
Javier Anderson Clear as mud. :)
Anyone have an easier explanation?
+senormedia you want him to dumb it down for ya?
That would seem to be implied in my question. . .
Great video. Thanks for sharing
This is just like my university professor - 60 years old, slow and boring, but conceptual masterpiece if you actually pay attention.
If you had to project a real live image of that, what would it look like?
Earlier in the video, we see that at a time, only one i.e. either electric and magnetic have their peaks (in electron flow pattern) but now during sign wave representation of the fields, both electric and magnetic fields have peaks at same time.
How is this possible now?
are you in Canada? where did you find this Royal Candians Air Force Film? secondly how did you copy it so well? NFB?
THIS IS GOLD
H for "Half cycle" DOH! I've been trying to get through my ARRL book and that's been bugging me...maybe I missed it, and maybe I'm mixing things up, but now I can at least remember H :)
Great, at last animation I can get my head around to understand..
Thanks
How we connect magnetron antenna to emitter antenna
excelent videos where and how did you got them, there is more videos? thanks
Do bugs with antennas produce radio waves?
thank you great explanations
best info film, thanks CAF.
Thanks for uploading this..
Hello sir! is there any way to connect with you?
student from india
Why are magnetic field fluxes not even at any point in the wire? Because I remember that electricity is even at any given point. Why the edges of wire have smaller magnetic field lines and the center has greater line? Wasn't it supposed to be like a cylinder rising in diameter and collapsing, but diameter even at any given point ?
this is perfect ! thank you
Muito obrigado por esse vídeo!!!
why do waves reflect from surfaces?
Because it is an obstacle , and there is no way to lose the energy of the wave so it just changes direction.
best ever
can microwave reflect from receiving antenna ? while receiving?
Great vedio, but i am a little puzzle about the amplitude of E plan and H plan, the 2 plan could not get the maximum value at the same time, there should be 90 degree phase difference, is this a typo?
No Mr 世鹏胡, they are with a 90° phase difference when they are in the "Near-Field-region" and there is no average power radiated , when the fields are in the "Far-Field-Region" they lose their 90° phase difference and now there is an non-zero average power radiated.
I hope that answer your questions.
Have a nice day.
Let me tell you my experience. All theories in RF transmission are good for classroom teaching. One has to practically do and learn in laboratory to understand antenna basics. I find huge differences between theory and practice. Infact I find certain things in books are entirely wrong or opposite. If it works it works because it works. Nothing works in deterministic way as the theory say. Simple things like material, conduction material, type of wire, grounding etc etc which makes huge difference in operation are conveniently neglected in books.
HOW can electron current flow without returning to the generator ?
Great video
Epic
the E field is a eléctric field??.
yes
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Why electric field produce magnetic field even when there is no charge in atmosphere?
great explaination
Very simplistic, but everyone has to start somewhere...
really helpfull!!thanks !
Wie is ook hier as gevolg van EERI 415?
it helped alot !!
thank you very much !
He says collapsing e and h fields are out of phase in the middle and e and h fields are in time and space quadrature??
How is it??
Javier Multisimas gracias thank you very much
How to make antina circuit
THNKS
salah ahmed no no out
Awesome!!!
Why the h field is maximum at centre of dipole? Can any one explain me plss
Great fun!
thank you
The H field?
magnetic field vector
i dont get anything in this world..why does the field reverse direction? why does it go back and forth why does the polarity change? why not just go?
Because of alternating current.
Very didactic!
Good video