#208

Ғылым және технология

This video illustrates how RF (radio frequency) standing waves are created in transmission lines - through the addition of the forward (transmitted) wave and the reflected wave that results from improperly terminating the line or matching the load or antenna to the transmission line impedance. I have done several videos that relate to transmission lines, terminations and reflections - all of which tell a piece of the story. This video is another piece, and I hope it helps you to understand how standing waves are formed and what the "look" like. This wikipedia link has some great graphics (shown in my video):
en.wikipedia.org/wiki/Standin...
Here's my video on transmission lines and terminations:
• #143: Transmission Lin...
Measuring the length and impedance of coax:
• #37: Use a scope to me...
How a directional coupler works:
• #196: How a Directiona...
Measure velocity factor of coax:
• #162: How to measure c...
RF Detector Probe used in this video:
• #161: Circuit Fun: a s...
Brilliant mechanical explanation and demonstration of wave propagation and reflections, courtesy of Bell Labs:
• AT&T Archives: Similia...
...and if you read this far, here's a challenge...
Brownie points to you if you can tell me how I created the "sliding" waveforms and displayed the static standing wave in the first half of the video.
Update: This video got posted on Hackaday!
hackaday.com/2015/08/06/visual...

Пікірлер: 368

  • @AppliedScience
    @AppliedScience9 жыл бұрын

    That is so cool! I've never seen RF power measured at different positions along a transmission line like that. I guess it's no surprise that it works, but it's always nice to see theory shown with an oscilloscope probe and a steady hand.

  • @MichaelOlsen-Engineer

    @MichaelOlsen-Engineer

    9 жыл бұрын

    Brilliant demo and explanation. Thanks for sharing!

  • @fdutrey

    @fdutrey

    9 жыл бұрын

    Applied Science Ben and Alan, you guys should meet up and do a video.

  • @w2aew

    @w2aew

    9 жыл бұрын

    Frédéric Dutrey I would *LOVE* that - too bad we're at opposite sides of the country!

  • @TheMrTape

    @TheMrTape

    9 жыл бұрын

    ***** If only there was a means by which you could collaborate and share data in real time over long distances. I long for the day when that becomes reality.

  • @w2aew

    @w2aew

    9 жыл бұрын

    Yeah, maybe when someone figures out this inter web thingy ;-)

  • @softwarephil1709
    @softwarephil17095 ай бұрын

    Outstanding demonstration of standing waves!

  • @Thesignalpath
    @Thesignalpath9 жыл бұрын

    Thanks Allen. I remember when we did this experiments when I was an undergrad during one of my courses in the lab, I had a "WOW!" moment which changed my perspective forever. :)

  • @w2aew

    @w2aew

    9 жыл бұрын

    The Signal Path Blog Yes, there's nothing like "seeing" things like this - really makes it "click!" Thanks for the comment!

  • @EETechs

    @EETechs

    9 жыл бұрын

    ***** Can you make a video explaining type 1 through 3 op amp compensation networks used for switch mode power supplies? Also, what does the "s" mean in (s+1) term in control theory for compensators and what does the H(s) function stand for?

  • @w2aew

    @w2aew

    9 жыл бұрын

    EETechs H(s) is the transfer function of the loop expressed using LaPlace transforms. This would be a more complicated topic and would likely have to encompass a few videos. I'll put it on the list though.

  • @bryceroberts581
    @bryceroberts5816 жыл бұрын

    This video is the absolute gold standard for demonstrating standing waves. A wiki page is one thing, but seeing the RF power minima and maxima being measured on an actual transmission line is quite another. Fantastic work W2AEW! 73 de W6PGS.

  • @yurikvelo

    @yurikvelo

    5 жыл бұрын

    one more animated visualization from me (made in HFSS) for coax line ypylypenko.livejournal.com/42947.html

  • @Parirash123
    @Parirash1234 жыл бұрын

    Wow, I never thought that I'll ever witness RF Standing wave so practically.

  • @hineko_
    @hineko_7 жыл бұрын

    I'm starting to think that utube is much better form of education than the universities. They never explained it this good at my U. In my case it was like here take this bunch of formulas, plug in numbers, calculate, congrats here's your bachelor's.

  • @w2aew

    @w2aew

    7 жыл бұрын

    You just have to find youtube instructors that explain things in a way that works for YOU! I'm glad that my videos do that for you.

  • @schwinn434

    @schwinn434

    5 жыл бұрын

    Unfortunately, I wasn't a very good student (and that's my fault), but I do think Alan's videos are much more educational than any lectures I received in my EE baccalaureate degree program; my lab classes didn't even use real oscilloscope probes (and, I had no knowledge what additional influences a home-made probe would have introduced , when high frequencies were used in a circuit- besides, we didn't have the equipment to generate anything over 200 megahertz, anyway, if my memory serves me well). We just used coaxial cables, stripped to the conductor on one end, with a BNC connector on the other end. It's embarrassing for me to admit, how much basic electronic science I've learned from Alan's videos - that I should have already know from my formal education as a EE student. I sure hope my university does a better job today educating future engineers - but, I doubt they do, since I can't imagine the lab classes having expensive modern electronic test equipment in them (too expensive). It blows my mind to think of the money wasted in education, when they could just buy some decent test equipment, and pay the correct people to demonstrate how to properly use the test gear - and what the equipment is measuring, and why; And I do believe in the idea of public education, and consider myself to be very much a liberal. However, just today I was reading, in our local paper, about our local convention center receiving an education award for educating children middle school and high school children- not sure of the exact grades; this convention center puts on these very silly plays, which are supposed to be comical (I guess), for which they bus in thousands of kids to watch, during the school day, and call this science education. I started watching one of the plays concerning science, and it was a joke (truly a joke), IMHO.

  • @patrickbouldinkm5l143

    @patrickbouldinkm5l143

    4 жыл бұрын

    @@WECB640 I think Walter did a great job with the pendulum explanation.

  • @MichaelLloyd
    @MichaelLloyd9 жыл бұрын

    You are very good at explaining somewhat hard to understand "things" in a way that makes them understandable. Thank you.

  • @bain5872

    @bain5872

    9 жыл бұрын

    Michael Lloyd I agree. I've never saw anyone else do it as good as he does.

  • @rameshbabu2704
    @rameshbabu27043 жыл бұрын

    Greetings from India, Alan you are my greatest RF guru

  • @ernieschatz3783
    @ernieschatz37835 жыл бұрын

    Your organized thought, visual aids and practical application is spot-on to me. So many You Tubers want to race through a subject without coming up for air. Also, you don't seem to have the tendency of diving down rabbit holes to the point where I feel I've been through a spin cycle! I rarely have to pause your videos either. I revisited this vid because memory is always the first thing to go!

  • @jmartin9865
    @jmartin98652 жыл бұрын

    This was fascinating. As a newish ham I never really got SWR until watching this. Thanks!!

  • @williamwalker8107
    @williamwalker8107 Жыл бұрын

    I like this practical literal demonstration of SWR stuff.

  • @makerspace533
    @makerspace5332 ай бұрын

    Nice demo. I have a large slotted line and an HP 415E I use to demonstrate SWR. If the crowd is very large, I hook a small amp and speaker to the amp output of the 415E so the 1000Hz tone can be heard around the room. I usually get some comments about the archaic equipment. Then I like to point out that this is the type of network analyzer that was used to design the equipment that brought back TV signals from the moon walks.

  • @VintageLabSilvioPinheiro
    @VintageLabSilvioPinheiro9 жыл бұрын

    Genius again. The best video i saw about stand waves. Clear, direct and simple. Sorry about my rusty english. Huge 59 S9+40 73 DE pu2srz

  • @jmex46
    @jmex469 жыл бұрын

    Thank you for taking the time to demonstrate standing waves. Great work!

  • @grantgiesbrecht2236
    @grantgiesbrecht22366 жыл бұрын

    Wow, I've never been able to see the effects of impedance matching as directly as you measured it here. It's very cool that you were able to measure the nodes and antinodes. Time to break out some PCBs and give it a try!

  • @Aemilindore
    @Aemilindore5 жыл бұрын

    Thanks for letting me see this phenomena. Although yuur previous video spoke of it, it was tough to believe it. This video gives the edge. Thank you so much.

  • @paulp1204
    @paulp1204 Жыл бұрын

    That was a terrific visualisation of an effect I understand, but had never witnessed so clearly. I've watched many of your fabulous videos, Alan, but this one has somehow eluded me. Glad to see it today. Thank you.

  • @naftilos76
    @naftilos763 жыл бұрын

    That is the coolest thing i have ever seen. Illustrating standing waves with this trick was just amazing. Great thinking! Bravo!

  • @borayurt66
    @borayurt667 жыл бұрын

    Great video! SWR explained without getting drowned in formulas and theory etc. Loved every moment of it. Thanks!

  • @MichaelShaw_vk2hms
    @MichaelShaw_vk2hms2 жыл бұрын

    This an excellent demonstration of VSWR. Thank you!

  • @bundangstluca
    @bundangstluca9 жыл бұрын

    Thumbs up! Great video to visualize standing waves on TML. The first time that I have seen such a kind of visualization.

  • @KB9DKA
    @KB9DKA3 жыл бұрын

    Amazing demo on Standing waves. Actuall measurement of the standing wave pattern on the live transmission line is absolutely unique. Much appreciated W2AEW !

  • @daic7274
    @daic72742 жыл бұрын

    Best demonstration of standing waves so far, and a useful function of persistence on a digital scope. Thank you.

  • @yaghiyahbrenner8902
    @yaghiyahbrenner89029 жыл бұрын

    Fantastic video. so much knowledge compressed in only 10 mins.

  • @pentachronic
    @pentachronic5 жыл бұрын

    Brilliant!! Never really understood this. Now I do !! You definitely have a gift for breaking apart the complex and showing us what is really going on.

  • @RohanSingh-py5cv
    @RohanSingh-py5cv6 жыл бұрын

    So awesome!! I'm studying about Transmission Lines right now and it's so cool to actually see all the theory presented in the books!

  • @martinhodge921
    @martinhodge9214 жыл бұрын

    In 10 minutes you've completely demystified standing waves for me. Thank you!

  • @ve6kk
    @ve6kk5 жыл бұрын

    Thanks so much again Alan. I wish I had your vids and ideas for test fixtures when I was teaching Engg. Techs. Standing waves are one of the hardest ideas to grasp so I sent this link to my basic ham class. And so happy that the classic Similarities of Wave Behavior is on KZread too. Cheers

  • @SnowyTurtleXD
    @SnowyTurtleXD Жыл бұрын

    Great video! Really helped me in understanding transmission lines for a project I'm completing for my PhD. Much appreciated!

  • @octavmandru9219
    @octavmandru92194 жыл бұрын

    You are a teacher that can do magic. Thank you for the effort you put in these teachings. Have you considered a teaching career?

  • @w2aew

    @w2aew

    4 жыл бұрын

    Maybe I'll teach after I retire...

  • @insightfool
    @insightfool2 жыл бұрын

    This is such a great intuitive explanation of things. Thanks so much!

  • @Avionics1958
    @Avionics19589 жыл бұрын

    I dont think any body can explain this any better and any clearer than you have Alain. You've nailed it.

  • @RedlabsTV
    @RedlabsTV Жыл бұрын

    Wow, your visualization methods help a lot to understand. Thank you!

  • @_egghead
    @_egghead6 жыл бұрын

    Thanks man. This does not only made me understand standing wave, but i now visualize the concept of transmission

  • @wa9kzy326
    @wa9kzy3265 жыл бұрын

    Fantastic presentation. Back in the day, we saw similar demos using "Letcher" wires. Nothing can be more informative than actually seeing the reality of the electric waves in their natural habitat, so to speak. Well done. In all of your videos, you have proven yourself to be a great teacher.

  • @RocketRoberts
    @RocketRoberts9 ай бұрын

    So great to see someone who knows the material explaining it well!

  • @forestfolks
    @forestfolks6 жыл бұрын

    Incredible! I've been struggling to understand SWR and this helped me a lot!

  • @JustSomeGuy1967
    @JustSomeGuy19679 жыл бұрын

    Your videos are always great. I'll be waiting for the next one !

  • @gerrysweeney
    @gerrysweeney6 жыл бұрын

    Thanks Alan, every time I watch one of your vids I know more about RF theory, I really like your practical illustrations of this sort of thing.

  • @w2aew

    @w2aew

    6 жыл бұрын

    Thank you Gerry!

  • @jonka1
    @jonka16 жыл бұрын

    Beautifully and perfectly illustrated.

  • @07kandarp
    @07kandarp6 жыл бұрын

    Amazing video as always, I was having a discussion with a friend of mine as to why the normalized impedance would repeat itself on a transmission line every half wavelength. This proves it. Also that is true for any termination except matched termination aka 50 ohms in most cases. Sits really well with the smith chart also. Alan you are true genius.

  • @rylanbrowne5658
    @rylanbrowne56583 жыл бұрын

    You make it so much easier to understand transmission line theory. It's pretty hard to visualise it just by reading about it.

  • @jspencerg
    @jspencerg Жыл бұрын

    Excellent practical demonstration of SW. I used to have students experience wave additions in the floor with 'super' slinkies. Similar wave behavior in different wave mediums makes understanding wave behavior so interesting.

  • @UberAlphaSirus
    @UberAlphaSirus9 жыл бұрын

    I don't know how you do it. I could read for a week on all this voodoo magic, and you Sir, sum it all up in 10 minutes. Your channel is one of the best I have have subbed.

  • @moustaphamuhammad7013

    @moustaphamuhammad7013

    5 жыл бұрын

    Yes, yes exactly!

  • @CalebDiT
    @CalebDiT7 жыл бұрын

    Great video! It's so nice to see things come together in reality after studying this stuff on paper.

  • @fjs1111
    @fjs11112 жыл бұрын

    Awesome visualization of standing waves as well as a description of constructive/destructive wave interference.

  • @PapasDino
    @PapasDino9 жыл бұрын

    As usual you make a complex topic so much easier to visualize in real life! 73 - Dino KL0S

  • @dank8981
    @dank89812 жыл бұрын

    This is really awesome. Really appreciate the demo.

  • @TheBdd4
    @TheBdd45 жыл бұрын

    Just saw saw this excellent video. I hope you are compensated in some way for all of your vauable videos! I have learned so much from you.

  • @mattkarlgaard1310
    @mattkarlgaard13109 жыл бұрын

    Thanks for sharing! I watched this video with my 9 year old and it got him excited to break out his littlebits.

  • @Impedancenetwork
    @Impedancenetwork7 жыл бұрын

    Ohhh man! That was awesome to see. I am literally learning about standing waves in my electromagnetics class right now. My brain started hurting so I stopped to watch some youtube. I just happen to type in standing waves and got this video. So nice to see what they are talking about in my EM book. All the equations and derivations just make you blind. This really helps me understand what is going on.

  • @RatedA4Aliens
    @RatedA4Aliens4 жыл бұрын

    Simply the best, this should be the supplementary video material for any transmission / Power related EE course

  • @BMRStudio
    @BMRStudio9 жыл бұрын

    Best RF teacher on the planet!

  • @acestudioscouk-Ace-G0ACE
    @acestudioscouk-Ace-G0ACE2 жыл бұрын

    To be able to "see" practically what the text books teach, is just amazing. It really helps to take the information on board. Thanks. You have so much content, I'm working my way through. Watch one, think and absorb, watch another... I could be half educated by the end of this! LOL

  • @ae6850
    @ae68505 жыл бұрын

    I've been following whenever; your way and material of explaining things is it. Thank you Sir. ae.

  • @DonzLockz
    @DonzLockz Жыл бұрын

    Amazing to actually see it in action! TY

  • @SteveTjiang
    @SteveTjiang3 жыл бұрын

    Awesome video. The visualization really helped me understand SWR

  • @alucardt3hvampireguy
    @alucardt3hvampireguy5 жыл бұрын

    I've had great trouble in the Electromagnetics course because while using Smith charts, we never went over what the transmission and reflection coefficients, nor the VSWR actually represented visually. Thanks so much for clearing this up.

  • @ekobbl2011
    @ekobbl20115 жыл бұрын

    Best explanation and practical demonstration ever! 4 thumbs up.....

  • @OscarJimenez-qo8go
    @OscarJimenez-qo8go3 жыл бұрын

    Fantastic video. Please continue making these informative videos on RF!

  • @Resonant87
    @Resonant878 жыл бұрын

    thank you so much for these videos you make understanding electricity sooo much easier.. you're doing amazing work

  • @DAVET38
    @DAVET389 жыл бұрын

    Another very interesting video Alan. Thank you.

  • @hubercats
    @hubercats2 жыл бұрын

    Another awesome demonstration, Alan. - Thank you! - Jim

  • @gurgen_a
    @gurgen_a6 жыл бұрын

    Really good demonstration!

  • @DucatiMTS1200
    @DucatiMTS12004 жыл бұрын

    Magic explanation and demo!

  • @cyberphox1
    @cyberphox111 ай бұрын

    That is an excellent video on standing waves.

  • @DenysSene
    @DenysSene7 жыл бұрын

    really great way to explain SWR.

  • @robertcalkjr.8325
    @robertcalkjr.83259 жыл бұрын

    Thanks Alan. Another great lesson.

  • @alperenalperen2458
    @alperenalperen24588 жыл бұрын

    A very clever demonstration

  • @LarsBerntzon
    @LarsBerntzon9 жыл бұрын

    Very nice and clear to see how it behaves

  • @moustaphamuhammad7013
    @moustaphamuhammad70135 жыл бұрын

    I can't stop watching that video over and over again. you are the master of desk experiment.

  • @sherwintiongson8197
    @sherwintiongson81974 жыл бұрын

    This is a fantastic video.

  • @karlfell3768
    @karlfell37689 жыл бұрын

    Another fantastic and informative video. Keep them coming. Karl

  • @EigenA
    @EigenA4 жыл бұрын

    Great job on bringing my Emag class to life. Thank you.

  • @davidgmos
    @davidgmos8 жыл бұрын

    Great demostration!

  • @sergiogarza8933
    @sergiogarza89333 жыл бұрын

    Phenomenal video, thank you so much.

  • @dannybeckett01
    @dannybeckett012 жыл бұрын

    Extremely good demo

  • @TheStoneWhisperer
    @TheStoneWhisperer2 жыл бұрын

    Well I feel like an infant listening to their first words! OMG! Some cool stuff here! I understood about 50% of it, but I took what I could from your words of wisdom! Thanks!

  • @davidcasement1296
    @davidcasement12963 жыл бұрын

    Nice Video. I clicked like and shared with some coworkers who are learning about this for FM Broadcast (Low power).

  • @andrewlamoureux2251
    @andrewlamoureux22517 жыл бұрын

    Great demonstration!

  • @RoboGenesHimanshuVerma
    @RoboGenesHimanshuVerma2 жыл бұрын

    So enjoyable and clean

  • @CoversTavo
    @CoversTavo2 жыл бұрын

    Wow dude... Excellent explanation! :)

  • @lupojacobo9892
    @lupojacobo98922 жыл бұрын

    Thanks for sharing your knowledge

  • @radiofun232
    @radiofun2324 жыл бұрын

    Perfect demo, 5 stars (cannot be explained better).

  • @rkdehury
    @rkdehury9 жыл бұрын

    excellent . great way of explanation.

  • @nlo114
    @nlo1146 жыл бұрын

    Excellent demonstration. This would have been good at my tech-college. It took me ages to understand this straight off a blackboard, in a class of semi-interested students.

  • @WilliamLaakkonen
    @WilliamLaakkonen9 жыл бұрын

    Well done indeed- reminds me of the old HP slotted lines we used at Solitron Microwave. 73

  • @davidausterman5915
    @davidausterman59153 жыл бұрын

    Brilliant video

  • @tank618
    @tank6187 жыл бұрын

    Excellently done!

  • @saarike
    @saarike4 жыл бұрын

    Absolutely great!

  • @yoramstein
    @yoramstein8 жыл бұрын

    Another great video .

  • @larrywiniarski1746
    @larrywiniarski17462 жыл бұрын

    Very very very very nice video. Thank you so much.

  • @annacersongor8553
    @annacersongor85533 жыл бұрын

    So beautiful ! Thanks sir, thanks a lot.

  • @isaacalejandroperezvazquez7143
    @isaacalejandroperezvazquez71437 ай бұрын

    Excelente video, gracias por tu conocimiento

  • @bgroisma
    @bgroisma3 жыл бұрын

    very clear and didactic video, congrats !

  • @kieranj67
    @kieranj675 жыл бұрын

    Thank you for this excellent video

  • @dougpeterson1925
    @dougpeterson19259 жыл бұрын

    Great video.

  • @wuftymerguftyguff
    @wuftymerguftyguff10 күн бұрын

    Thanks Allen, very useful

  • @dd0356
    @dd03565 жыл бұрын

    I wish we had videos like these when they taught waves & antennas in college. All the test equipment were costly, we did not have time, and the teacher wasn't really interested because we could not visualize it! but it looks so cool :)

  • @kevinobrien8803
    @kevinobrien88039 жыл бұрын

    Fantastic video

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