Demystifying Smith Charts for Ham Radio Beginners
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- เผยแพร่เมื่อ 17 ก.พ. 2024
- Are you ready to take your ham radio game to the next level? Well, look no further than mastering Smith Charts. Smith Charts are essential tools for analyzing RF circuits and antennas. They can help you understand impedance matching, transmission lines, and much more.
But they can be overwhelming at first glance. That's why in this video, we will break down the basics of Smith Charts to help you become more comfortable using them. By the end of this video, you will have a solid foundation in using Smith Charts for your ham radio projects. So grab your notebook and pen, and let's dive in together.
Thanks for watching! Don't forget to subscribe to our channel for more ham radio tutorials and tips.
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A video with more detail on Impedance: th-cam.com/video/orS0Qodaats/w-d-xo.htmlsi=LFCmomVvpDaVW2VF
The reference to 7200 khz is priceless!
Hey Tam, the response to this video was more positive than I expected. I will do more on the Smith Chart 👍
Professor Ape in the house! If it matters, These are my favorite type of videos.. Well done, thanks for making this. Shared it
Howdy Andy, glad you liked it bro!
This actually clears away a lot of the fog that I had about Smith Charts that I encountered studying for my extra. Thanks!!
Glad to hear it Dell, thanks for watching 👍
A nice and easy introduction of the Smith Chart.
Glad you liked it!
You had me lmfao when you said 7.200. 😂. I hope everyone else gets it.
Haha, thanks for watching 👍
@@TheSmokinApe my pleasure you have good videos plus educational content
Gald you like them
That comment had me choking on my morning coffee. 😂
I was laughing, too. I can’t believe what a train wreck that freq is. It’s embarrassing, actually.
4:40 LOL! 🤣 This is excellent Ape. Keep educating and raising the bar. 73
haha, thanks for checking it out Hollywood!
I really like this video. If possible, I would love for you to build on this, please. For me, it would help to see actual numbers from a current system plotted, and then how to interpret and use the Smith Chart to adjust and improve the current system.
Hey Tam. The response to this video has been better than what I expected. I will do more stuff on the Smith Chart in the future 👍
Thanks Ape. First science class I've taken in 45 years. I could have used this when I self-taught for my Extra!
Hey Doug, glad you liked it 👍
Very good description of a Smith Chart! Probably one of the best. And, I liked the “stab” at 7200 gang 😆
Thanks Rohn, glad you liked it 👍
I really enjoy these "actually informative " videos. Every now and then, it helps knock the rust off of the deeper understanding of your topics. 73, K1DLA
Thanks Don, glad you like them 👍
Thank you for making this video!
Thanks for watching Scott 👍
Hands down the best Smith Chart explanation I have ever seen. The last time I tried to wrap my head around Smith Charts was while studying the ARRL Extra License Manual. I have been avoiding them since.
When I found the smith chart on the NanoVNA it was everything I wanted / needed to know to get my antennas working
I have SWR / Logmag, but it is the Smith chart I go to to work out how to fix issues.
For example, a friend was putting up a fan dipole for 40 & 80. We could get a match on 40, but the match on 80 was pretty ordinary. Best SWR was 1.8:1
I had a look at the smith chart and it showed, what I expected, that the impedance was a little low at resonance because of its proximity to the ground.
Simple fix. Increase the impedance at resonance by feeding the 80m dipole slightly off centre. Worked a treat….until the weather took it down a few months later. :-/
Thanks SF, glad it was helpful 👍
Awesome story MidLife, I agree. Once I got the Nano I started to understand antenna behavior much better 👍
@@TheSmokinApe I used to use a home made gate dip oscillator. Had a set of coils wound on wooden kite dowel shoved into a 3 pin DIN plug. Used that to find resonance and then add some sort of L match at the feed to get the SWR right.
These days we are so spoilt for affordable tech to home brew, VNAs Spectrum analyzers. Storage Oscilloscopes and function generators. Even component testers for $20
Almost no excuse not to be making stuff. Antennas, match units, radio gear…you just have to get over the optional anxiety of which one project to start on 😊
Wow! Seeing graph paper and a fancy compass sent my mind back to college in the 1980’s and made me want to hold my HP-41CX calculator. 😊
lol, thanks for watching Brian 👍
now I feel that I have to look for more videos to see the effect of the other variables. Please keep these videos coming
I can do more more on Smith Charts, I do have a few on Impedance 👍
Hopefully the start of a series! Looking forward to it, being able to read the smith chart on the NanoVNA lets you do all sorts of things with ease, like finding distance to a cable break, ideal components needed to match an antenna, adjusting baluns for that perfect 1:1 SWR, making perfect 90 degree phasing lines etc.
The NanoVNA spoils us and is a very powerful tool, and the online "will kelsey smith chart" will let you muck around with matching networks and give you an intuitive feeling for how they work.
Hey GDL, this video had a better response than I expected, so I will do more. AND you are right, there are a few good online tools that are helpful, thanks for watching bro 👍
Massively useful and very interesting video. I really appreciate you taking the time to do this ❤
Glad you liked it, thank you for watching 👍
Excellent Ape, thank you for sharing that Smith Chart information.
Thanks for watching Janice 👍
a very VERY good presentation. Bravo!
Thank you very much!
Good stuff!! I learned this years ago and really needed a refresher.
Thanks for watching Mark, glad you liked it 👍
G'day Ape,
It was me that asked for you to do this video and I'm really glad I asked!
Great to see that some other folks found some value in it too.
Just a note for people that are new to Smith Charts and struggle to remember which hemisphere of the chart is which, IndUctance has a U in it, this is the Upper hemisphere.
I realised that as soon as I saw your diagram!
Oddly enough Ape, where did you get that Smith Chart print-out from?
That looks like a really handy tool for a newbie to charts, like me.
Cheers,
Mike T
Hey Mike, it wasn't just you. There are a few flavors of Smith Charts, here is the one I used for the video: www.eeweb.com/wp-content/uploads/smith-chart.pdf
Many thanks. Love these. You get to the point without bloviating. Very helpful.
Hey James, glad you liked it. Thanks for watching 👍
Very informative Ape! Thanks bro!
Hey BA, glad you liked it 👍
K got me @ 11 p.m est this is new too me let's check this out ..honestly as a 11 meter person in my late 40s and thinking about going futher i find your videos very informative..keep up the good work cheers
THanks Adam, glad you like the videos 👍
OMFG Dude I needed this so much you have no idea. Finally I get it.
Thanks awesome Ben, glad to hear it was helpful 👍
Nice one! Thanks!!!
Thanks for watching SS
Great video Ape. 👍
Thanks Dan 🍻
Nice dude!!
Thanks Allen 👍
👍Thank you sir,
Thanks for watching 👍
I get to go to bed smarter than when i woke up
Haha, thanks for watching Cliff
Good start on the Smith chart! by the way, an antenna can be resonant on more than one frequency, and they can line up right on or near the other bands we have privileges on because of the harmonics. it was designed that way. and the guy who told you about the open feed line was giving you information. if you have an antenna field 400ft away from your shack, instead of running high-dollar massive coax use an open feed line it will save a lot of money and be better. there are places to use all of the different designs. everyone lives in a different situation with different problems to overcome.
I have a lot of friends who use open wire feedline, I put comments in like that to joke with them. So, when it comes to antenna like EFHW that are harmonically "resonate" on multiple bands, that's not really the case. An antenna generally "that's the word I used in the video" is resonate on a single frequency and near resonate on harmonically related frequencies. I have bult, bought and tested a great number of them and I have never seen one that was truly resonate on any HF frequency much less multiples. Thanks for watching Curt 👍
you need to do a 1/4 wave. the matching network will make them resonate on single frequencies. try a simple 40 meter dipole you will be resonant on multiple frequencies. don't expect a 1:1 match every where, but you will be able to use a lot.@@TheSmokinApe
You don't know how bad I needed this
SideBoom!
@@TheSmokinApe you know us CB'ers can't read nothing but swinging needles
@@ubergeek318 well, I wasn’t gonna say anything…
Well explained. Lol, this wouldn't made for easier studying for the extra ticket. Thanks and 73, KF0NNQ.
Hey Bill, thanks for checking it out 👍
Now i know when I find that package of smith charts in my shack as I move that I should keep them.
Right
Thanks for the video that I needed.
What area of the country are you at?
Glad you like the videos 👍 I'm going with south central USA!
Hi. Any possibility you might make a Part 2 to show how the Nano traces the response on the Smith Chart as the frequency slowly sweeps?
I'll work something out. The response to this video is more positive than I expected so I will do more.
Damn ape you now have me thinkin your primate nickname is a ruse! Might think about going with “The Professor” 🧐 and it also goes well with your cahr buddies. Let’s see Chuck be “Mr. Howell” 💰 Jeem be like “Gilligan” 🤪 even though he more resembles the “Skipper” TO is kinda a hybrid “Skipper as he’s always jabbing at Jeem but he also has a lot of professor qualities. 👨✈️🧐 I’m sure someone can come up with a catchy new theme song for y’all! Oh and what an excellent video right here explaining the smith chart🧐
Haha, thanks Goober, I will let the boys know we have a new show idea...
Great help, thanks. So, in an ideal word that SWR circle needs to be as small as possible and centred slap bang in the centre of the chart? If the centre of the circle is above the "equator" then you need to add capacitance to the antenna and similarly if the centre of the SWR circle is below the "equator" you need to add inductance? Any tips on how to do this? I suppose that would be dependent on the type of antenna?
In reality, resonant or near-resonant dipoles can be thought of electrically as loops. What comes around goes around. So if you have a dipole, somewhat near the center feedpoint you can add inductance or capacitance to counter what reactance you have measured. Lets say you have 100 ohms capacitive measured at the dipole feedpoint. you can add near the feedpoint a coil with an XL of 100 ohms. Remember I said it looks electrically like a loop, you can add 2-50 ohm coils on each side of the dipole instead of 1-100 ohm on one side. Which side doesn't matter. It's like a loop.
That being said, the impedance of a halfwave changes so if you have a OCFD or an end-fed. do the correction near the center of the halfwave antenna and not at the feedpoint as the correction can be smaller. That's going to require some calculation as to what you will need to have, but it can be done.
The length of the antenna determines the radiation resistance. The resistive losses will be fairly constant. I say this because we all know that the center fed dipole is around 72 ohms. You can shorten the antenna until it's 50 ohms and you can add the inductance to cancel the added capacitive reactance of the antenna. Then you can approach a perfect match at some point in the band. Not the whole band.
Of course use good workmanship techniques and use strain relief and strong wires and coil forms. If you have an inductive antenna, be concerned with your capacitance voltage ratings and it needs to be a tough capacitor. You can look at a doorknob capacitor for some of the strongest components or build your own with a capacitance or NanoVNA meter to make adjustments.
So you need capacitance to cancel too much inductance, an inductor to cancel too much capacitance and a transmission line transformer to correct to the center of the Smith Chart.
Good luck. N9XR
Hey M7BXR, you are on the right track. I would appear my friend, at least I think we are friends, Mr. BDRFI nailed it as always.
@@TheSmokinApe I liked his last 2 letters on the callsign.
@@BusDriverRFI I knew it had to be something 👍
I was wondering if you could address the topic of how the shape of induction coils affects the bandwidth. I built a 110 micro Henry coil for my end fed half wave, but I’m wondering what shape would give me the best performance, long and thin, or fat and short.
I can, I will put it on the long list. Short answer is fat, short with space between the coils is more efficient.
Hey, can you make a smith chart video?
I’ll get to it one of these days, kinda busy with cat videos at the moment
@@TheSmokinApe Oh my.
Right
Is there any way to take what you discover on your rig expert or similar device and translate that to determining what your incidence angle is, and can you take the data collected and incorporate that into any antenna modeling software like EZNEC or MMANA-GAL?
There's no correlation between the Smith Chart and the radiation pattern. Whatsoever.
The Smith Chart discussion is one topic. Radiation patterns is another topic. You can determine the Smith Chart data from an antenna design, but you can't determine an antenna design or radiation pattern from a Smith Chart set of data.
de N9XR.
Hey HVACER, Mr. BDRFI is correct.
Thanks for the video but I will suggest a more down to earth video like in a 10k feet above where I can just take my antenna analyzer or nano VNA, do a sweep and understand what is telling me IN BASICS in regard of "the antenna is good for my purpose"?, etc but VERY "for dumb people" like me which are not interest in all that information you provided (which is great for other people) and we can just do a sweep and in less than 10 seconds understand where we at, like when reading SWR. Also ive seen many times when shopping for an antenna where the manufacturer shows a smith chart and I have no clue what is telling me, it will be great if at that time in 5 seconds I could understand if is good for my purpose or not. If you can give examples even better. I hope I'm explaining myself. Thanks for all your help understanding stuff
Hey Angel. Sometimes folks feel dumb, but that's because they are exposed to something new, over time the complex will become simple. We are all new at first and feel this way. Look at it like this, in order to interpret a Smith Chart at a glance you need to know the parts of the Smith Chart and what they mean, that's what I covered in the video along with some extra stuff. If you even only take that part away you have a stronger understanding than before AND the next time, it's less complex. Thanks for watching 👍
You are completely right my friend. Is just that sometimes we live a life so busy that the little bit of time we have to play radios is to take a tool and find “it works? No? Move one” you know. I hope one day (probably when retire) have the time and brain to learn all the ins and outs. Thanks for your honest and down to earth reply.
Thanks for watching Angel 👍
How about the equator being the path of least "resistance".
Maybe, but I think the OMs say "pure resistance" 👍
Yeah I know, I was just desperate to squeeze in a cheap pun! I loved your explanation. These diagrams used to make me dizzy!@@TheSmokinApe
What does SWR mean?
Standing wave ratio
This dont look basic Son!😂
I needs moe edumacating!😁
C'mon son!
@@TheSmokinApe 😄👍
Not all of the power bounces back and forth like a ping-pong ball. Just as a majority of the forward power passes into the antenna except for the reflected power, a portion of the reflected power passes through the trans-match into the radio. How much depends on the impedance mismatch between the 50 ohm cable and the impedance of the trans-match.
That's a totally loaded question.
1. First of all, the signal doesn't bounce back and forth if you use a transmatch and it is set for 1:1 SWR. It only bounces back and forth if you have an unmatched transmatch or no transmatch with a reasonably high SWR. Of course it can only be matched at one frequency, yada yada yada. I'm talking about staying within your tolerance you set.
2. Second. Look at your smith chart. Where it's at is important. If it's RESONANT, then your transmatch should load to your antenna well. The transmatch will transform the voltage and set the voltage to optimize the power into the antenna.
3. Third. If it's inductive or capacitive, your antenna is setting up a power factor that will shift the current phase and common mode currents will then exist. Your feedline will radiate. Even if your SWR at the transmitter says 1:1, your transmission line is radiating.
4. Lastly, if the antenna is very close to 50+j0 you don't need a transmatch.
Where you are along that circle you can draw in the middle is important to know beyond the fact that everywhere along the circle it's at the same SWR. Good Luck.
de N9XR
I thought you said this was for beginners?😂😂
Absorb what you can and re-run the video. Absorb more. This one is fairly good.
@BusDriverRFI I'll revisit it after I learn some other things that pertains to antenna propagation
@@deplorable-0ne Smith Charts has really little to do with propagation. It has little to do with radiation patterns. You can derive smith chart values from an antenna design but you can't derive an antenna design from a Smith Chart.
@BusDriverRFI so it's basically plotting the electrical values of an antenna on a chart after its built?
Thanks BDRFI
Reeeee trans match. He’s making fun of rot pockets!!!!
Everyone loves hot pockets 👍
@@TheSmokinApe mmmmmmm. Yes indeed.
Right
Thanks! Now I have a headache! I recently got a Nano and you have taught me a lot. WB7WBW
lol, thanks for watching bro 👍
It is probably a niggly point but... reflected waves are created at impedance discontinuities. Very common at the junction of feed lines and antennas. That might be the Transmatch but doesn't have to be. The entire feed might be 50 Ohm non-reactive right up to the internals of the output stage of the transmitter (and is especially evident in tube type amplifiers). Transistor amplifiers disguise a lot of useful metrics that tube amplifiers are metered to present.
And that brings up another useful to know concept. All discussions regarding SWR need to consider the different effects on the signal source, depending largely on technology. The impedance of tube amplifiers are thousands of Ohms away from transistor amplifiers and tubes are voltage devices whereas transistors are current devices. This means things. When working with transmission impedance transforms the in-phase voltages have very different impacts on system survivability in full-power transient mismatches such as a falling limb might produce. Theories then, to be consistent, have to consider the specific technologies involved. Nobody running a micropower QRP rig is going to see flames issue from their breadboard rig if the neighbor's walnut tree falls on their antenna, but if they are running 1KW from a pair of grounded grid 3-500Z tubes they may have an entirely different experience.
Thanks for the info on the tube amps, I really don't have much experience with them.
🤷 *promosm*
Bitter much?