#275

Picking up where video #274 left off, this video gets into several practical aspects of using a Smith Chart to take care of doing complex calculations involving VSWR, reflection coefficient (gamma and rho), return loss, and the impedance transformations that occur when using transmission line between a source (generator, transmitter, etc.) and the load (antenna, amplifier input, etc.).
Show Notes:
www.qsl.net/w2aew/youtube/Smit...
Check out my friend Mike's awesome iPhone/iPad app that automates these Smith Chart and Impedance conversions, and the associated introductory video:
apps.apple.com/us/app/impedan...
• Smith Chart Calculatio...

[@theFailQuail]

this 15min video did a better job of explaining smith charts and how to use them than my EM professor did in 3 hours worth of lectures. Great work!

[@pcfreak1992]

This channel is like an RF version of the channel “Applied Science” and I love it. Every video has such an amazing value. Thank you!

[@ajinkyamunge]

You have the most lucid explanations of all things electronic. Absolutely love your videos!

[@DonDegidio]

Hi Alan, You deserve two thumbs up for that explanation and examples. You made it easily understood and I've been a ham for 40 years. 73 WB3BJU

[@WisdomVendor1]

I haven't seen a VSWR chart(that's what I called it) since I was taking microwave theory while in electrical engineering at university back in the mid '80's. This brings back a lot of memories. I recall the first one I ever saw, it scared the hell outta me. It was the most complicated graph paper I'd ever seen. It turned out to be very simple and handy. The elegance of it is amazing.

[@kellingc]

I always love your content. Smith charts was one of my weakest areas on the Extra exam, but I find I understand it a lot better now.

[@shilok21682]

Thank you so much for all the hard work you have done in making all of your videos!!! They have been extremely helpful to me in the field when I need to brush up on things. Stay healthy my friend.

[@wk2w]

Once again, can't thank you enough for another great explanation. I've spent considerable time reading about Smith charts and watching many videos on impedance matching. Your explanations, along with the practical use applications, answer many of the questions that remain unanswered from the other sources.Throwing some wire up into a tree to make an antenna is fun, but there is an inexplicable joy in learning the theory and design. Your contribution to the hobby, and to those of us who wish to learn is immeasurable. I hope you find the same joy in creating these videos.

[@epleace]

My "Intro to RF circuits" class just started this precise topic - you explanation is a great help. Thank you.

[@kalgeriax1016]

Blessed you man, Damn I was so confused when my lecture teaches this through online class. With unclear video quality and constant internet lagging my god I was dying. You save my day!

[@wxfreak]

Thank you for explaining something that I've never been able to understand on my own. You are a good teacher.

[@andycooper1684]

Two fantastic videos on Smith Charts - thanks Alan, I look forward to more on the subject.

[@josephcorteo]

Hello Alan, Thank you again for another superb video! Your videos are an invaluable resource for students and practicing engineers alike.

[@W1RMD]

Great! Started watching these after our discussion. I will practice with Smith charts in the future. I always was in rush to just put up an easy antenna before and that was good enough. I've know found a new thrill in learning how it all works. Thanks!

[@cache4pat]

This video provides a gold mine of insights; bringing 'long past learnt skills' back to life & fun to reconsider ... Thank you.

[@sraiken]

Excellent explanation. I somewhat know how to use a Smith chart. In my last project I built matching networks each time we needed to use this special antenna. My best tool for know which way to go, and how much, with either inductance or capacitance in a network under construction, was the Smith chart. I am still learning thanks to guys like you

[@conconmervin]

As always, great tutorial. I wish you were my instructor when I was still in college. Thank you very much.

[@Chris.Schulz]

This video helps me out so much. I will be watching again with a lot of other videos you have made. Thanks for the added notes also.

[@ShayneLoa]

thanks for this. watching it in April 2024!

[@PapasDino]

A great continuing saga, TNX Alan, look forward to future installments! 73 - Dino KL0S

[@WestCoastMole]

Well Done Alan. This video along with the previous will go on my 'recommended list' to hams that are looking for more information on the subjects of complex impedance and transmission line theory. This is the type of stuff the ARRL should be doing. I am genuinely impressed.

[@johnc8910]

The ARRL IS doing this, just not as elegantly (in the engineering sense).

[@stevenwilliams6258]

A little late seeing this video, you gave practical uses for the Smith chart. I haven't looked at this since college in the early 80's and only vaguely remember the name. I worked in control systems and some digital design but find this interesting. I have thought about a nanoVNA just to play with some concepts. Your video(s) make it easier to experiment with these concepts.

[@MichaelLloyd]

I have been looking for a video like this for years! Thank you very much 73 NE5U Mike

[@w2aew]

A really cool web-based Smith chart simulator can be found here: niyeradori.github.io/QuickSmith-Web/index.html SimSmith, a phenomenal FREE Smith Chart simulator for Windows: ae6ty.com/Smith_Charts.html Great KZbin videos on SimSmith, by Larry W0QE: kzbin.info/door/KSyLSu4fm_1RHoO3Jvk4YQ

[@sayantanmaiti2513]

Thanks for the links Sir.

[@RohanSingh-py5cv]

Finally I can understand Smith Charts. 🙏

[@GiNodrog]

Clearest explanation I've seen / heard. Brilliant.

[@mrkattm]

Awesome job explaining the practical uses of a smith charts, my personal epiphany moment understanding smith charts came when I was trimming a 1/4 wave matching length of coax for a delta loop that I was experimenting with, it is so funny how one little insight like that can make everything else just fall into place. Again, great job and thanks for sharing.

[@LEO22116]

The video is just great and to the point, very helpful at the same time. Keep up the good work!

[@___xyz___]

I am completely new to this, and don't understand more than a small part of what you discuss in the video. But it is really exciting and I'm hoping to learn it soon enough when it becomes relevant! Thank you very much!

[@rlamb51]

I’ve always had trouble with Smith Charts. Maybe because the text writers didn’t have much experience with smith charts themselves. I will be saving this video. Very understandable detailed explanation. Thanks.

[@DrFrank-xj9bc]

Very well prepared and performed video. Your sonorous lectures really are really restorative for brain & soul.

[@xfyang6154]

Thanks w2aew! This is a great teaching video.

[@philippe5394]

Hi Alan, well explained as usual with a very good sequence. I put it into practice on a laminated diagram. I am now waiting for the third of the série!! many thanks Alan.

[@darrenolafson5266]

This is the most thorough tutorial on the Smith chart that I've seen. Thanks again. va7deo

[@w2aew]

Thanks - there will be more to come in the future....

[@Inspironator]

Excellent refresher. Thumbs up given, as usual!

[@blickberg8404]

Awesome. I really enjoyed this lecture for breakfast this morning.

[@amanbatra8864]

Hats off! What a wonderful explanation of a complex topic.

[@barrosamanda]

thanks for your explanation. much easy understand than my teacher! best regards from Canada

[@christian67472]

Congratulations, it helps me in the classess of Microwaves and Transmission Lines.

[@AAFX-OM]

Thank you for making these great videos.

[@RadioDude1969]

Excellent video! I really enjoy your channel. Thanks!

[@swad2315]

thank you my friend may you have a wonderful day

[@topphemlig1191]

Great video Alan, this helps a lot!

[@KingLoopie1]

Old video, but extremely well done for me as I try to catch up... 👍

[@TomSny35]

Great instructional video. Thank you!

[@engineerx7180]

Thanks A lot Sir The ways you explains every thing was just awesome. it was really helpful. You deserve more then a Thumbs. I wish to be your student! Thanks Again.

[@IZ0MTW]

Amazing. Invaluable informations. Thanks also for the pdf notes. 73s

[@legionaire4017]

I always look forward to your videos! thanks again for creating these thorough explanations that you clearly spend a great deal of time preparing. The educational value of your content should be commended and I'm glad to see the comments here at you tube doing just that. Have you considered starting a Patreon? I know I'd be happy to donate to help you help me!

[@w2aew]

Thank you. Undecided about Patreon at the moment. I do have a "donate" button via PayPal on the channel page - at the moment this is the only way to financially support the channel. I'll keep Patreon in mind...

[@tekvax01]

WOW! expertly explained! Where were you back in 1994 when I had to do this in school?!

[@Luzt.]

It's strange this content was not considered "sensitive, proprietary, national security" by some three-letter-agency and blocked for viewers outside US. Superb!

[@thekaduu]

Thanks for another nice video!

[@youcefyahiaoui1465]

Beautifully done! Kudos.

[@andrewgrant396]

I would be very interested in seeing a direct application of a smith chart to RF circuit design. For example, design a matching network to go between an antenna and IC. Thanks for your videos!

[@w2aew]

I'm planning on such videos - just need to lay the ground work first....

[@danielbjohnson]

w2aew thanks for that! something that confused me in the past when doing the same sort of design was microstrip, stripline, etc for transmission lines in conjunction with antenna baluns to integrated circuit designs. Any content including this stuff in your examples as well would be helpful content.

[@moustaphamuhammad7013]

@@w2aew we are waiting for your delicious videos!

[@w2aew]

@@moustaphamuhammad7013 Seek and ye shall find - here are a few videos. The first two lay the ground work, and the last is a design example: kzbin.info/www/bejne/naiUhYyNrMupfc0 kzbin.info/www/bejne/f56xg5aXasqWfJI kzbin.info/www/bejne/f5jIg3t6fpKoocU

[@dronereaper7]

awesome! please keep them coming , thanks.

[@fishyrider3528]

Oh man. Can I call you proffesor? I really apreciate what you do. Keep it going. And a big thank you.

[@TheScarceshadow]

Thank you so much for this video, this helped me a lot with my electronics homework

[@leopoldoalvarez6787]

Excelente explicacion del uso del carta de Smith en lineas de transmisión..., muy bueno...!!, un resumen de menos de 20 minutos en una clase que dura dos semanas entenderlo..., estupendo..!!, gracias

[@mrjohhhnnnyyy5797]

What can I say, Smith chart is awesome. Makes it easy to get values that are real pain to calculate.

[@786jinga]

I love it soo much! Awesome work Alan. Eager to see a video on Design of matching N/W !!!! :) :)

[@azariahasafoagyei1580]

Thanks w2aew!

[@typedef_]

This was a really nice explanation.

[@mike4330]

Alan, this series is a good example of ham spirit. I suspect Smith charts are the amateur radio equivalent of eating your vegetables. Thanks for making it palatable! Btw, your draftsmanship is impressive! de K5ROE

[@Iffythegreat]

This was amazing and super helpful

[@ZlayaCo6aka]

FWIW, on a related subject: For V/UHF work, cut your test jumpers to a multiple of a half wavelength; it'll make your measurements and tunings better and easier. For HF, you can cobble a set of extension jumpers to add to your 10-meter jumper.

[@Radiowild]

Great explanation! Thank heavens for antenna analyzers, since this amount of math makes my head spin! lol

[@devanandmd]

U are a saviour for us

[@johanroos6348]

Very well explained. Thx

[@ct7afr326]

Excellent video, again! Thanks for your works. Vy 73 de CT7AFR, Emmanuel.

[@Aurnox47]

you made my day Boss

[@ornithopterindia]

👍Thank you sir.

[@Fh_Ndiritu]

This is amazing!

[@alaaalshurufat2998]

genius in facilitating complex subjects....

[@shortwavelistener]

Nicely done! Thank you!

[@jay16myv.]

thank you for the lesson.

[@aerorcuav]

Thank you sir.Very useful video..Great !! Subscribed !

[@relaxedvibe2382]

Thanks man. Straight up!!!

[@wemme]

Nice video. Would have been great to see the return loss plot on the vna. But thanks for the smith chart series.

[@urlkrueger]

WOW !!! Never realized there was that much capability in a Smith Chart. Makes it painful to think about how much I don't know what I don't know.

[@w2aew]

This is the tip of the iceberg on the Smith chart - there's more it can do....

[@yytvo212]

Absolutely clear and inspiring. It prompted me to think how to use Smith chart if Z0 of the transmission line does not equal to Z0 of the system, for example adding a 75 Ohm line to a 50 Ohm generator. Any suggestions?

[@siddhantnayak8773]

very nice lecture

[@jakubniemczuk]

I would LOVE to see a video on PCB rf voodo elements. Maybe an example on a PCB directional coupler or a h/4 transformer.

[@edeinsteineinstenio5058]

thank you sr.

[@funkyironman69]

Wow! Just found the website you got your smith chart from (url bottom left corner of chart). Been looking for a high quality smith chart image for awhile.

[@billigerfusel]

You explained it way better than the prof.

[@AnuritaRay-cv9jr]

While solving for the input impedance at the generator side, 8:40, did you assume the characteristic impedance of the coax to be 50 ohms? What if the charecteristic impedance is not the same as the source impedance?

[@neuralnetwork653]

Thank you!

[@nevzatsadik2145]

life saver !! thank u

[@CH_Pechiar]

Alan, excellent video, as usual. Maybe Andrew already suggested this but, in my words, it would be great to know how to use the charts to 'fix' an antenna (ie, make it resonant at the desired frequency). Once having the complex impedance of the [non resonant] antenna [or load] at that given frequency, let the charts show us what to put in parallel o series (an L, a C, a combination or even a piece of a coax of a different characteristic impedance) to fix the antenna. Thanks !!!

[@w2aew]

I do plan on doing a video or two on designing matching circuits using the Smith chart...

[@JackZimmermann]

Really looking forward to those videos! Great as always, thanks!

[@davidgrey943]

Hi, where do you get copies of the blank smith chart sheets.?

[@w2aew]

I simply used Google to find PDF or other formats of Smith charts, and then print them myself.

[@yavuzciftci8283]

hi dear can we calculate the absorbed power by absorber from only the reflection coefficient? for example calculate the absorbed power by absorber when the reflection coefficient is -20dB

[@zerovolt24]

Hello Alan, thanks for the great video. I watched it more than once and every time I grab a concept that I missed before. One question: in the last example of the 1m coax cable, is it's characteristic impedance irrelevant for the calculations of the impedance seen from the generator? It would be nice to see a video on the theory and practice of using cables with different Z0.

[@w2aew]

The Z0 actually does affect the impedance seen by the generator. It is normally simply factored in by normalizing the chart to Z0 (Z0 in the center of the Smith chart). If you plot the impedance seen at the generator as a function of transmission line length - you'll get a circle that is centered on Z0. If you have a transmission line that is not at the same Z0 as the chart, then you'll get a circle centered on the line's Z0 value.

[@johnadams9558]

Do you have any videos addressing the interaction of frequency with all those other variables? Such as when a vna performs a sweep to determine optimal frequency resonance of antennas? Also, why do you call it “real”? Reading the Smith Chart chapter in ARRL Ant. Book ch. 28 they only refer to reactance and resistance.

[@w2aew]

I do have other videos showing the operation of a VNA to do frequency sweeps. When I refer to "real", I am referring to the resistance part of the impedance. Complex impedance consists of Resistance and reactance, and are expressed mathematically with complex numbers consisting of "real" and "imaginary" parts.

[@warplanner8852]

Alan, this is flabbergasting! How did Mr Smith figure this intricate chart out snd still have time to develop those great cough drops with his brother? : -} Seriously, it is a very good explanation of a fascinating subject. It would be interesting to understand the math and geometry behind the Smith chart.

[@rolandprocell]

Honestly! How can someone gave thumbs down on a video like this one??

[@unamonoteismo1686]

I want to understand these things but i cant afford going to school for it now..how can i start..is there a good video where i can start from

[@rapsod1911]

What is characteristic impedance of scope probes coax cable?

[@russellpalmer5610]

Just out of curiosity, does the impedance develop from the wire type resistance factor? i.e.: would it vary if it were copper wire, aluminum wire, or whatever else? (regardless of size factors but dealing with length)

[@w2aew]

The transmission line impedance is derived from the distributed capacitance and inductance of the line. Ideally, the resistance will be as low as possible.

[@aborabie1572]

Thanks sir

[@sadivelakshmiprasadreddy6424]

thank you sir...

[@aneeshmp200745]

It would be great if you can show us tuning some chip or PCB antena with VNA thanks for your videos