@@BobDarlington Perhaps we could all learn something if you share what you believe these errors are? Otherwise your comment is not only useless, but annoying.
This man is the best eletronics and DYI TH-camr, not only he explains why things work like they do but also tells the truth and shows what he means. Thank you Andreas for making these videos and helping thousands making little projects that seemed impossible before!
I watched this video in the past and now I went back to watch it again to ask questions. I'm just frustrated that I can't press the "Like" button again. Thank you again master.
The expensive equipment had unlocked the, "black art of RF" to me decades ago. (It's easy with the right tools.) THANK YOU for your _perfectly_ concise explanation of the theory, and FOR SHOWING THESE _DELIGHTFULLY AFFORDABLE_ DIY TOOLS!
Ok, Ok....... so once again you introduce me to another topic (I thought I had no interest in). Once again your enthusiasm for the subject, along with the way you present, is just a dream. At the speed you are going, I have to wonder what wonders you have for us in the future. My life is enriched every Sunday by your work and often I spend the week thinking it over. I’m surprised you hardly mentioned how much you loved your new tool 🤥 Keep going Andreas, you are an authority on so many subjects.
I had 61 years to learn. So, some things are buried somewhere in my brains. Like antenna theory. I had to build my own antennas when I was a radio operator in the war zone of N'Djamena already in the 1980s ;-)
Thank you Andreas, as a French, I like your Swiss accent, and I remain admirative in front of the simplicity with which you can explain complex subjects ...I'll keep watching your multiple videos and keep learning ... Your experiments basically save me the hassle of trial and errors, and help me to go straight to the right solution. Bravo !
That does it !!! It's 40 years since I used a Smith chart. 15 years working with HF/VHF/UHF antennas with the old tools. What would we have given for tools like that? Yes, I see why you fell in love with it! I'm off to your Patreon channel - give us more like this.
I have been using a nanovna for a couple of years and have found it very useful for tuning and troubleshooting antennas. Every time I use it I am amazed that such a cheap tool can give me the same information as the $80,000 analyzer I use at work. Obviously I don't expect it to be perfect but I have compared it and found it surprisingly close.
I agree. When the first cheap devices appeared on the market, I had suspicions and also compared it with an expensive instrument. Already then, the results were usable for my purposes.
I was a Microwave Technician and took a 9 month Special class about antennas, learned all the basics, theory and use of the Smith Chart and went on to work to help build 4-18 Ghz microwave amplifiers here in Silicon Valley, there were a lot of tuning using the microcope, tuning is like black magic with a skill using those little gold chips and soldering / tacking them when the desired SWR was achieved. I would like to buy one of these... hahaha... I'd like to learn how to use this HIGH TECH DEVICE 'AWESOME'...
As a life long antenna building nerd, I really appreciated this video. I've had my eye on one of these inexpensive VNAs for some time. Now I'll be sure to get one.
LOL! I remember in trade school asking the head of the electronics department about antenna matching. "Complex impedance.... That is a dark art of the field" Nice to see it described as such from you.
I typically transmit signals from 300 mW to 3 W when trying to communicate with my Amateur Radio. Prior to recent times the technology that you describe was not available to most hobbyists. Glad that technology is making measuring devices like this that I can afford on my retirement pension. I enjoy building my antennas, mostly for HF.
They do, or at least they try. But it's presented as if you're an electrical engineering student. That's doesn't work with everyone. Definitely didn't with me, and I spent a career in technology.
This is good work, Andreas. You explain things very clearly so that I can understand things that I have not understood for many years. Thank you so much.
OH WOW, THANK YOU! !!!. This is one of your best videos to date. Antennae theory and practice is something that most of electronics hobbyists have to always rely on others, such as vendors and manufacturers, when we build with RF modules such as Lora etc. Using this video the theory and practice is now approachable. - IN A COLOUR GRAPH!!!! You have really showed us how we can optimise our own antennae using tools that even we hobbyists can consider getting. Thank you again! One question please Andreas, please could tell us if this device can be used for wifi/ES32/ESP82xx, GSM and other similar modules that all play with. I know you said that the 2.2 GHz band is covered, but is it just as effective in that range? Sorry if I missed this the video but it wasn't clear to me. Ps. The other thing that wasn't clear was whether you loved this new tool? :-)
Concerning 2.4 GHz: We did not focus on that range so I cannot tell you if the results are as good as they were below 1 GHz. But I assume they are ok, too. I saw a video somewhere where the guy used it for WiFi antenna testing.
@@AndreasSpiess Hello Andreas, Do you have experience with the management of Rigexpert? I have the AA-600, but it remains at 600mhz maximum. I was looking at several models, which at least could analyze the 2.4-2.5Ghz band, for wifi antennas, and have appeared yours N1201A, the Vna Tiny and another one that is much more expensive, the KC901V, which comes to cover the wifi antennas of double band. I would like to know if the measurements of the N1201A are quite accurate, since I would like to use it to make high sensitivity Bluetooth antennas. Thanks for your mythical tutorials. I wait your answer. Best regards from Barcelona, Catalonia.
Great video .. You should have included how to measure the antenna impedance using the NS1201SA. You can tune the radials by bending them at an angle and measuring the change in impedance at the specific frequency. You can also use the VNA to cut optimum length feed lines. Did I mention I love this tool too :-)
Excellent video! It's worth adding that altering an RF transmitter's performance in any way can easily put you on the wrong side of the law in one's home country, and that doing so is obviously (and entirely) at their own risk.
Being a engineer this is a great video, love that tool as well for something simple and portable when I don't want to drag out the analyzer and extension cord.
Thank you for getting into antenna theory. Because your explanations are so easy to understand, I think I will be able to learn basics of antennae theory from this series
Andreas, the length of the coax is also important. Perhaps you can make a video on how, some time is better to put the amplifier also with the antenna on the roof.. .. And measure the comparison on power reflected.
Great video again, I will have to have one of those analysers, I was brought up on an HP VNA and have seen that the price of professional equipment has tumbled down in recent years. Remember the Anritsu Sitemaster? So helpful to have the comparison with a 'known good' analyser - better than any sales pitch. Now, what would be interesting (because you like testing outdoors and now have the tools) it would be really interesting to show the impact of antenna optimisation on your radio link budget in real terms of RSSI. Again, great video, keep it up. (Ian T) :-)
Super great video, I love this N1201SA device. BTW: The open/closed SMA connectors are easy to build for everyone. For the 50 Ohm load, a 100 Ohm 0.1% (two parallel ERA-6AEB101V Panasonic) resistors will do the job.
Andreas, thanks for the great video. I think it would be a nice idea to set up a website where the performance, or resonating frequency of these antennas is documented. These VNA tools are still quite expensive for the regular maker, also because you usually have to pay custom fees for more expensive items. Maybe a simple public Google sheets will work for this, or a Google sites website?
Sometimes there are maker spaces that have all the fancy equipment. Maybe build your antenna and take it there! :) Then everyone shares all the equipment. I hear some places even have the thing that goes bleep! ;)
@@AndreasSpiess but yours videos are the best - lot of useful knowledge put in a human friendly way. I really appreciate the way in which you explain complex things. N1201SA looks like a nice small analyzer. But still not as affordable as it could be. Did you heard about Nano-VNA (~50$ VNA which works up to 900 MHz)? Do you plan to show it in your videos? In my opinion it looks like a game changer for amateur RF engineers/ham radio operators. Vy 73 de Juliusz SQ2JUL
Order for the tester placed. My guess is that Shenzhen Boss Digital Electronic Co is going to be very happy for this video also. :) Tip for people not using the AliExpress app - very often products are discounted for mobile orders. In this case 6% discount. I've been wondering why this is with a tin foil hat in my head.
A very informative video, but I listened to the "power transfer" explanation at 5:20 to 5:45 minutes into the video multiple times to try to make sense of what was said. I concluded that there was a misunderstanding between the phrase "power transfer" and "current flow". The current flow is maximum at dc because the reactance of the inductor vanishes there. The current flow is also maximum at infinite frequency because the reactance of the capacitor vanishes there. But the "power transfer" also vanishes at both ends because the voltage drops to zero there, and power is the product of voltage and current. Power transfer is maximum at resonance precisely because that is the frequency at which there is an optimum compromise between voltage and current.
Maybe you are right. I assumed the circuit is in series (comparable with a cable) and assumed, that, if I have no voltage across this "cable", 100% of the power is transferred into the load. Your view is probably a little different.
Thanks for your reply. The video describes a parallel LC combination, which is why the current is maximum at the frequency extremes. There is no voltage drop across the LC combination, and all of the power is disastrously deposited in the source. If it had been a series LC, then there would be no current at the extremes, and again no power transfer to the LC combination at the extremes. In either case, maximum power transfer occurs at resonance, n'est-ce-pas?
The net effect is that the LC combination, which is simulating the antenna, gets maximum power transfer at resonance. If it is a parallel combination, then the source is in danger of being destroyed by too a high current at the frequency extremes. If it is a series combination, then the source is in danger of being over-voltaged (a factor of two, and maybe more).
You make very nice videos, for me some parts are review but some is new, kind of to radio stuff but have done electronics for years. Thanks again for sharing!
After watching this video I ordered the N1202SA. And Sir, You were right, it is a great tool! I have tried to find an adapter that could be used to measure the IPX connector small antennas. Can You give some tips where to find adapter that makes it possible to test antennas having u.fl and IPX female connector? You are doing excellent job helping people to get in to electronics. Oh, and did I already mention that I love Your videos ;-)
@@AndreasSpiess - Good day, and apologies for not responding to your kind reply above. - Did you ever measure the FINAL cut length of your TUNED antenna ??? >82mm or
Another, possibly less expensive, way to do it is in reverse using an RF spectrum analyzer; set your transmitter to output a constant signal, measure the received signal, and trim the transmitter antenna until you get the best result on the spectrum analyzer. It could be argued that this is even more useful because the nature of your overall project design can greatly de-tune your antenna, and this way you can visualize what works best for your specific needs. I am not ashamed to admit I have made commercial products using this approach, as simply designing an antenna to make a VNA happy does not tell you anything about how that antenna actually performs in-circuit, next to other parts, inside an enclosure, etc.
I would not agree that a VNA does not tell you anything in the situations we generally use (the antenna is outside the case). I used a similar method you propose also in a video (only on one frequency). It is dependable if you are able to put the antenna at the place where it stays, but also creates a little more effort. If you move the antenna you have the same issues as with a VNA. Another problem could be the law if you want to scan larger frequency bands. BTW: Where do you get your Spectrum Analyzers for less than 150$ ;-)
In my case I virtually always use an antenna that is inside the enclosure, which does cost me a little radiated power but keeps the design small and clean (especially good when my project is to be used by non-technical people). I did not mean to suggest a VNA has no use, just that it cannot tell you how an antenna performs "in place". Most SDRs cover the necessary frequency range, and some of them are shockingly inexpensive (although I do use a $300 handheld spectrum analyzer, the "RF Explorer"). I forgot to say that I really liked this video, and think that this is of GREAT value to new engineers who are understandably afraid of the RF dark arts! :)
This video is awesome Andreas, Just wondering who are those 6 jealous people which dislike this wonderful video? 1.4K(up to the present) is much much bigger than 6 !!!! Probably their antennas are not adjusted exactly to your channel frequency !!!
I find the N1201SA analyzer very usefull. I have one. I would recommend it too. I would prefer a good spectrum analyzer with larger bandwidth but I cannot justify the cost.
Hi, thanks for the video, which introduced the N1201sa to me. I looked for further information and was astonished to learn there are not many information at all, beside of a few TH-cam Videos. E.g. There are many different models now. N1201sa the one you introduced N1201sa+ with an extended frequency range down to 37MHz N1201sac which adds a ttl serial port for communication. Then there seems to be a successor N2201SS, which seem to add a TX port, but Infos on that is very spare and most is misleading, e.g. the description of the N1201sa is given albeit the N2201SS is for sale. No infos whether different versions of the N2201 exists. Finally some sellers offer a N2061SA which also seems to offer a TX port for a frequency range from 1.1 MHz to 1.3 GHz. Albeit no more infos can be found. Esp. Further spec differences between the N2201 and the N2061 would be interesting. All Infos so fare are from Chinese sellers on the usual platforms. We all know how much we can trust those information... Heck, I couldn't even find the original manufacture homepage. No comparison tables, no reviews for the later two models. Nothing... even in Chinese information on the internet are rather spare. Much interesting would be a miniVNA tiny vs a N2201SS comparison, to get an idea about the performance in this price range. Both follow different ideas about usability etc. but at the end those might be what a hobbyist is looking for. Maybe that is a good idea for a part two of this video. ;)
I cannot Test VNAs. The only I tested with a colleague is the one I showed. The mini seems to be ok and the software works. For the moment I do not plan an additional video. I use the small one for my antenna tuning and the miniVna if I want to learn about Smith chart.
Well, I understand this. Was hoping that others can provide more information about all those different models. Identifying the original manufacturer would be a good start already. If you would have to decide for one, the N1201sa or the minivna tiny, which would you give a preference?
Thank you, very useful info on Antennas. I'd love to learn what are the things to be considered if you soldered a LoRa module to a PCB. So then routing a track from LoRa module to the antenna. I'd imagine you could make quite a mess.
I would never take it apart. The risk is too high that it does not work anymore. That would be a catastrophe for my relation to this small device ;-) For your info: It consists of an ADF4350 and a SA612A mixer plus the usual STM processor and charging circuits.
1:14 I'd say the ground plane antenna has been the #1 most common antenna type in the world for over half a century, there's been one on almost every car and truck ever made that came with an AM/FM radio for well over the last 80+ years and by 1946 there were an estimated 9 million AM car radios in use and currently over 1 billion estimated on the roads today not counting the ones no longer being used. Mobile device antennas might have changed that though.
If you call all vertical antennas "Ground Planes" you are right. Often, the word "GP" is used for 1/4 wavelength radiating elements. Then An AM antenna would have been quite long ;-) That's why they often were loaded/shortened with inductors.
@@AndreasSpiess no, not ALL vertical antennas are GP's, there are vertical dipoles after all... But in the case of vehicles we are not typically talking about a "radiating" vertical element like we would expect for a ham "transistor" radio that can transmit too as well as just receive. Vehicle AM/FM radio antennas typically only have to "receive" which is much more forgiving and can be MUCH smaller fractions of a full, half or even a quarter λ to work...
@@AndreasSpiess I would even imagine "some" mobile radios could be considered a GP antenna too because your body acts as the ground plane. With my cheap UV-5R radio my hand capacitance acts as either the bottom of a dipole or a ground plane depending who you ask and the same could be said of other mobile devices too. What is your opinion on that matter Andreas?
This was the last video on antennas for a while. There are better channels for that if you are interested in antennas. I want to keep this channel broad, and not trivial, but not only for specialists.
Please note that, for low power transmitters, it's often worthwhile to design it to attach directly to the antenna. This removes coaxial cable losses totally. If you need to get data some distance to the transmitter, a data cable is much cheaper than coax at any length.
I see that you are very close to explaining the Smith chart and it's usefullness :-) But it would be hard without complex impedance :-) Very nice video!
Great tool, I am wating for one that can measure 5.8GHz for FPV so that I can get a better idea why some of my penny antennas are doing as good or better than some commercial ones. BTW you have an interesting last name, makes one think.
The best Andreas video in my opinion... and yes, we must keep politicians in the resonance regime so that they can cancel themselves... Is there a video of the VNA you show at the end? keep the good work!
I'd not have trusted these things without your recommendation. Thanks for taking the risk on our behalf with such a wonderfully qualified response. Does this mean you have RAK troubles? :)
No I've been playing with adding GPS and running things in Docker - now there is a whole track of video possabilities (have the antenna tester on it's way - I bet China is empty of the things after your commendation).
Yes right. The theory can be a bit dry, but to see it in real life and discover the result as you go is like a eureka moment for the viewer when you see it.
Hello Andreas! Really amazing video - it really deserves three thumbs up! It help to solve problems people usually does not know it exists at all. By the way: do you think it is worth to invest additional 50 EUR into newer model N2201SS?
This is not a newer model, it has more features. But I do not know it (ant the software coming with it). I bought the miniVNA instead. Just for antenna tuning, I cannot imagine you would see a difference between the two because you do not need the second port.
Andreas, bal-un, "bal" as in bal-anced & "un", as in un-balanced, not bal-oon ;) Also, frequency of resonance or resonant frequency :) Parasitic capacitance or parasitic inductance, not " built-in". Another interesting and useful video!
Hello Mr. Andreas! Excellent video very pleasant to watch and informative, but remains a question, what's the difference between N1201A vs N2201SA? Is there other feature available? As a suggestion, could you please do some antenna construction videos? Thanks in advance!
Andreas - Excellent informative video. But maybe i misunderstood one point. You said "these VNA's must br calibrated using these three items", but i can't figure out if you mean if you buy the n1201a you will have to calibrate it, or if you mean if you want to calibrate it.
At 12:00 you said you found no significant difference between the two analyzers. If I am reading the units correctly, one is showing an S11 of -28dB at 868MHz, the other is at -20dB. If this was for the same antenna then I would say that is a significant difference. But yeah great bang for the buck for this little thing and great video overall.
You are right (even if both results show excellent antennas VSWR 1.2 vs 1.1). We did not focus too much on the absolute values for the antennas because we did the measurements inside on a bench. There were some differences, also because of the setup. Especially with antennas. We more focused on the relative curve, which, in our judgement, is sufficient for antenna optimization. But we also measured a filter which removed most of the environment variables. And there the results were good.
@@AndreasSpiess you should have dug a little deeper into this unit, as it should be the center of attention, and it's filled with information and values and would likely be a helping hand to many people to explain what many of these values mean alongside the graph for these values.?. as the voltage standing wave ratio, pretty on call with the meaning of that aspect. and yep at the sub 90 bucks (USD), they seem to go for, its a nice tool, definitely. imgur.com/a/3kHMlnW If you have another video on this unit that goes more into actual item-details & features and meaning' or your familiar with one that tests this unit more thoroughly' please share..
A difference of 8 dB sounds like a lot, but is it in this case? It is important to remember what exactly it is you are measuring. S11 is reflected power or return loss. So S11 = -20dB means that 1% of transmitted power is coming back from the antenna or load, and -28dB means that less than 1% is coming back. Is that a big difference, or in fact any noticeable difference at all in how your antenna system performs? You may see a change at that level by bending a coax feed cable just slightly more or less. For this price, a VNA measurement in UHF band to 1% in power ratio seems pretty good to me.
WOw!! Wonderful review! BTW, the aliexpress link shows a large number of devices most of which have colored numbers on the display and one that show the graph like you have in the video. Which one should I pick?
Hi and thank you for your very interesting video regarding antenna measuring and the VNA. I se that the vendor also have seveloped the N2201SS VNA with two ports. Would you consider testing and reviewing the N221SS extra features as well? In addition to power meter, it is supposed to support some extra measurement features. S21?. With so many poorly manufactured antennas for RC and FPV hobbyists, this kind of knowledge and tools are of great interest and benefit. Thanks! Kind regards Torgeir
Excellent presentation! Now we look forward to your review of the MiniVNA Tiny clone. I may be tempted to buy one if it is any good. I have the 1st. gen MiniVNA and are quite satisfied with it, except that it does not go higher than 180MHz. So I would buy the one you show there if it is a tool and not just an expensive random number generator. And did you really think you would get away by showing us an RMA and a RMA-RP in the same picture with no mention of it? Mate those two and measure the WSWR through them! It should be pretty high. ;-)
1. I have no plan for a VNA review for the moment. 2. SMA connectors should be 50 ohms (and they usually are).. So two connectors in series are not too critical.
Thanks Andreas, awesome video as always. quick question .. can I change one of those common 2.4GHz antennas to operate on 900MHz with the help of N1201SA?
Thanks, very helpful and still affordable tool! Thanks for sharing. There are so many antennas on aliexpress or eBay and you never know what you get. This tool helps to sort out the non reliable vendors and to find the well matched antennas. In my understanding you can see if the antenna is matching. But how can you find out something about the gain and directionality?
Excellent video. I also have china antennas which work correctly only when the plastic cover is removed. Do you think the designers were unaware of the dielectric effect ? Abit like the antenna problem on one of the earlier iphones ?
@@AndreasSpiess When we used dual wall adhesive heat shrink to ruggedize a Smiley 5/8 wave SAR antenna, it decreased the velocity factor and the result was we needed to trim an extra 2mm (as compared to the same tune point for the stock Smiley with no heat shrink) in order to optimize the best SWR and impedance for our target tuned frequency.
Note that using springs and other "gimmics" to tune the antenna will give false results. The radiation resistance of the antenna itself must be 50 ohms, not a combination of gimmics plus the antenna. The actual signal radiation can be significantly off even if the apparent resistance is a nicely matched 50 ohms.
I am not sure I understand. With the VNA I only check of the power is radiated by the antenna or reflected back to the transmitter. I cannot tell anything about the radiation pattern nor the gain of an antenna. But reflected power never is radiated... I am one of your subscribers, BTW :-)
I now have one of these analyzers thanks to your video and recommendation. It's actually the two-port model so in the future I may be able to do more than just S11 measurements. However, I have a mystery. The VNA works well for my custom made antennas, and shows many purchased ones are crap. However... I have a length of coax that identifies itself as RG-58A, but feels far more flexible than I'd expect. While I don't intend to actually use this for an antenna as it's too lossy at 915 Mhz, it seems to show a constant VSWR across all frequencies from the lowest I can go with this unit up to the maximum. It doesn't matter if I short the cable end or not, and I have tested the cable for shorts between the center and shield, and there are none. I do have an older model MFJ analyzer that can go down to at least 1 MHz, so I'll likely test it on that later. However, this is either an expected yet shocking to me characteristic of this long cable, the cable is defective, or the tool can't cope. In this case, I suspect it's the former -- all the signal IS being absorbed, so the S11 looks AMAZING as there is no reflected power, the VSWR is AMAZING as there is no reflected power, and the impedance is spot-on.
I cannot tell it from here. But it would be interesting if any power leaves the other end... To prove your theory that all power is lost. It is anyway a strange behavior.
Great video and the MiniVNA Tiny looks like exactly what I want as it covers such a wide range of frequencies shame it seems like its no longer available. Where did you get yours? It seems a little different in the metal case so maybe you found an alternative supplier? By the way can you also do a review of the even cheaper MR300 (based on SARK 100) which is good up to 60 MHz. Not good for these antenna's it's true, but for us HAM's... :)
I got mine from the link provided. Maybe you search on AliExpress. Or the supplier just was sold out for a few days? I will not cover a low-frequency VNA because I have no use for it. But there are a few amateur radio related channels (e.g. WA2AEW) which are better prepared for such a review.
Andreas Spiess I did a search as suggested and although it seems the original supplier doesn't sell them I found a supplier of an updated device based on the original. Thanks for the reply. 73s
wonderfull video to understant a little more of the magic subject. Plus a free introduction to political understanding of switzerland. Great Being very concerned with 5.8 Vtx and antennas, do you know a similar version of a VNA up to 5.9 GHz ?
Thanks for good video! You adjusted length of a portable antenna while it was connected to the VNA. Does case of the VNA affect antenna properties? I mean once you disconnect that antenna from the VNA and connect that antenna to a radio, it might not match exactly the same. If radio case is bigger or smaller than VNA case or if it is made of different materials the antenna will match differently to the radio.
Every change changes the properties. So you can try to emulate the situation as good as possible. You see this also if you touch the SMA connector while you measure with the VNA
i am an electronic engineer for around 20 years and I can tell that this tutorial is one of the best tutorials I had seen
Thank you for your nice words!
Maybe that's the difference. I do this stuff for a living. Lots of errors in the first 5 minutes.
@@BobDarlington Perhaps we could all learn something if you share what you believe these errors are?
Otherwise your comment is not only useless, but annoying.
Very true.... and that's when someone is super knowledgeable and super funny and knows how to combine them :)
@@martym2464 agreed!
This man is the best eletronics and DYI TH-camr, not only he explains why things work like they do but also tells the truth and shows what he means. Thank you Andreas for making these videos and helping thousands making little projects that seemed impossible before!
Thank you for your nice words!
I watched this video in the past and now I went back to watch it again to ask questions. I'm just frustrated that I can't press the "Like" button again. Thank you again master.
Thank you. Did you watch my newest ones about the topic?
The expensive equipment had unlocked the, "black art of RF" to me decades ago.
(It's easy with the right tools.) THANK YOU for your _perfectly_ concise explanation
of the theory, and FOR SHOWING THESE _DELIGHTFULLY AFFORDABLE_ DIY TOOLS!
You might be aware that I was (sightly) delighted too when I made this video...
AGREED - #MeToo LOL >>> I relied on the maths and precision construction,... but was BLIND to the real / actual tuning.
.
Now when I am working with electronics I have a Swiss voice in my head.. Dankeschön
Bitteschön!
This unit is excellent. This one of the most addictive radio tools I have every owned - just cannot stop making antennas!!
Ok, Ok....... so once again you introduce me to another topic (I thought I had no interest in).
Once again your enthusiasm for the subject, along with the way you present, is just a dream.
At the speed you are going, I have to wonder what wonders you have for us in the future.
My life is enriched every Sunday by your work and often I spend the week thinking it over.
I’m surprised you hardly mentioned how much you loved your new tool
🤥
Keep going Andreas, you are an authority on so many subjects.
I had 61 years to learn. So, some things are buried somewhere in my brains. Like antenna theory. I had to build my own antennas when I was a radio operator in the war zone of N'Djamena already in the 1980s ;-)
I have learned more things from your videos on practical and theoretical electronics than in my 4 years in the EE school.
Thank you!
Thank you Andreas, as a French, I like your Swiss accent, and I remain admirative in front of the simplicity with which you can explain complex subjects ...I'll keep watching your multiple videos and keep learning ... Your experiments basically save me the hassle of trial and errors, and help me to go straight to the right solution. Bravo !
Thank you for your nice words!
That does it !!!
It's 40 years since I used a Smith chart. 15 years working with HF/VHF/UHF antennas with the old tools. What would we have given for tools like that?
Yes, I see why you fell in love with it! I'm off to your Patreon channel - give us more like this.
This is the reason I like this part a lot...
Thanks, really enjoyed video, well done! I am 76 and a retired electrical engineer / technician. Never too-old to lean new technology!
You are right! I have a few viewers at your age. So our profession seems to be healthy for the brains ;-)
I *really* like how show some theorie , but always tied to practical usage! Had to order that device .. no chance to resist ;)
Yes; resistance is futile. Now order yours right away, if you have enough capacitance.
+ Water: I am sure you will enjoy it.+ FindLiberty: I like your comment!
I have been using a nanovna for a couple of years and have found it very useful for tuning and troubleshooting antennas. Every time I use it I am amazed that such a cheap tool can give me the same information as the $80,000 analyzer I use at work. Obviously I don't expect it to be perfect but I have compared it and found it surprisingly close.
I agree. When the first cheap devices appeared on the market, I had suspicions and also compared it with an expensive instrument. Already then, the results were usable for my purposes.
I was a Microwave Technician and took a 9 month Special class about antennas, learned all the basics, theory and use of the Smith Chart and went on to work to help build 4-18 Ghz microwave amplifiers here in Silicon Valley, there were a lot of tuning using the microcope, tuning is like black magic with a skill using those little gold chips and soldering / tacking them when the desired SWR was achieved. I would like to buy one of these... hahaha... I'd like to learn how to use this HIGH TECH DEVICE 'AWESOME'...
Maybe you watch my video about the NanoVNA. This is a more modern version (which also shows the Smith chart)
Its a great time to be alive if you are in the electronics/technical/software fields
You are absolutely right. I enjoy it every day!
As a life long antenna building nerd, I really appreciated this video. I've had my eye on one of these inexpensive VNAs for some time. Now I'll be sure to get one.
I am sure you will enjoy it.
LOL! I remember in trade school asking the head of the electronics department about antenna matching. "Complex impedance.... That is a dark art of the field"
Nice to see it described as such from you.
:-)
I typically transmit signals from 300 mW to 3 W when trying to communicate with my Amateur Radio. Prior to recent times the technology that you describe was not available to most hobbyists. Glad that technology is making measuring devices like this that I can afford on my retirement pension. I enjoy building my antennas, mostly for HF.
Things changed considerably since we were young. And now I feel like living in a "electronics paradise"
I have no experience and knowledge about antenna. But I am learning a lot from your tutorial. Thank you so much.
Glad to hear that!
I learned more about antennas in this 16 minute video than I did from by Extra Class license course. Thanks!
Not good. They should learn you how it works before you buy a 1kW amplifier ;-)
They do, or at least they try. But it's presented as if you're an electrical engineering student. That's doesn't work with everyone. Definitely didn't with me, and I spent a career in technology.
Andreas, you are a legend. I learnt more in the first 5 minutes of this video than I had in months of playing around with DIY antennas :)
Antennas are not easy and the knowledge is not widely spread. So I am glad the video was helpful.
This is good work, Andreas. You explain things very clearly so that I can understand things that I have not understood for many years. Thank you so much.
You are welcome! Glad my videos help.
OH WOW, THANK YOU! !!!. This is one of your best videos to date. Antennae theory and practice is something that most of electronics hobbyists have to always rely on others, such as vendors and manufacturers, when we build with RF modules such as Lora etc. Using this video the theory and practice is now approachable. - IN A COLOUR GRAPH!!!! You have really showed us how we can optimise our own antennae using tools that even we hobbyists can consider getting. Thank you again!
One question please Andreas, please could tell us if this device can be used for wifi/ES32/ESP82xx, GSM and other similar modules that all play with. I know you said that the 2.2 GHz band is covered, but is it just as effective in that range? Sorry if I missed this the video but it wasn't clear to me.
Ps. The other thing that wasn't clear was whether you loved this new tool? :-)
Concerning 2.4 GHz: We did not focus on that range so I cannot tell you if the results are as good as they were below 1 GHz. But I assume they are ok, too. I saw a video somewhere where the guy used it for WiFi antenna testing.
northshorepx p
@@AndreasSpiess Hello Andreas, Do you have experience with the management of Rigexpert? I have the AA-600, but it remains at 600mhz maximum. I was looking at several models, which at least could analyze the 2.4-2.5Ghz band, for wifi antennas, and have appeared yours N1201A, the Vna Tiny and another one that is much more expensive, the KC901V, which comes to cover the wifi antennas of double band.
I would like to know if the measurements of the N1201A are quite accurate, since I would like to use it to make high sensitivity Bluetooth antennas.
Thanks for your mythical tutorials.
I wait your answer.
Best regards from Barcelona, Catalonia.
Again Andreas has surpassed all the others!! You earned my patronage!!! Keep up the good work!!
Thank you for your support!
Great video .. You should have included how to measure the antenna impedance using the NS1201SA. You can tune the radials by bending them at an angle and measuring the change in impedance at the specific frequency. You can also use the VNA to cut optimum length feed lines. Did I mention I love this tool too :-)
You are right. But the video should not get too long and I always leave something to discover by ma viewers.
Excellent video! It's worth adding that altering an RF transmitter's performance in any way can easily put you on the wrong side of the law in one's home country, and that doing so is obviously (and entirely) at their own risk.
Thanks for your info. I hope, my viewers know what they do...
Being a engineer this is a great video, love that tool as well for something simple and portable when I don't want to drag out the analyzer and extension cord.
Many of my viewers bought one and I got quite good feedback about it.
Thank you for getting into antenna theory. Because your explanations are so easy to understand, I think I will be able to learn basics of antennae theory from this series
You are welcome!
Andreas, the length of the coax is also important. Perhaps you can make a video on how, some time is better to put the amplifier also with the antenna on the roof.. .. And measure the comparison on power reflected.
Something else I didn't know I needed until now LOL This would have been awesome 30 years ago when I was doing VHF/UHF radio work.
You are right. We live in a wonderful world (electronically)
It seems you really like your new tool ;-) Thanks for the content, very interesting, as usual.
Yes, it is very useful for me.
Great video again, I will have to have one of those analysers, I was brought up on an HP VNA and have seen that the price of professional equipment has tumbled down in recent years. Remember the Anritsu Sitemaster? So helpful to have the comparison with a 'known good' analyser - better than any sales pitch. Now, what would be interesting (because you like testing outdoors and now have the tools) it would be really interesting to show the impact of antenna optimisation on your radio link budget in real terms of RSSI. Again, great video, keep it up. (Ian T) :-)
This was the last antenna video for a while on this channel. Many other topics are waiting...
So Andreas, I was wondering, do you like the N1201SA Vector Network Analyser. Couldn't quite tell... 😜 Excellent video, sir.
I wanted to leave everybody uncertain about that fact. Glad I succeeded ;-)
John Burns Exactly my thoughts! 😂
Super great video, I love this N1201SA device.
BTW: The open/closed SMA connectors are easy to build for everyone. For the 50 Ohm load, a 100 Ohm 0.1% (two parallel ERA-6AEB101V Panasonic) resistors will do the job.
So you were more successful than me. We did some tests with a "homemade and a "bought" open and short. The differences were noticeable already at 868.
Andreas, thanks for the great video. I think it would be a nice idea to set up a website where the performance, or resonating frequency of these antennas is documented. These VNA tools are still quite expensive for the regular maker, also because you usually have to pay custom fees for more expensive items. Maybe a simple public Google sheets will work for this, or a Google sites website?
You never know if our dealers change their suppliers. I can only test what I have on my bench.
Sometimes there are maker spaces that have all the fancy equipment. Maybe build your antenna and take it there! :) Then everyone shares all the equipment. I hear some places even have the thing that goes bleep! ;)
How about more videos on the VNA and the other things you can do with it? Interpretation of Smith charts would make an interesting one...
I am not sure how far I will go with this special RF technology on this channel. There are more specialized channels for that, I think.
@@AndreasSpiess but yours videos are the best - lot of useful knowledge put in a human friendly way. I really appreciate the way in which you explain complex things.
N1201SA looks like a nice small analyzer. But still not as affordable as it could be. Did you heard about Nano-VNA (~50$ VNA which works up to 900 MHz)? Do you plan to show it in your videos? In my opinion it looks like a game changer for amateur RF engineers/ham radio operators.
Vy 73 de Juliusz SQ2JUL
Super useful information presented in a clear, concise and convincing manner. Thank you once again! Anxiously waiting for the next video...
Order for the tester placed. My guess is that Shenzhen Boss Digital Electronic Co is going to be very happy for this video also. :) Tip for people not using the AliExpress app - very often products are discounted for mobile orders. In this case 6% discount. I've been wondering why this is with a tin foil hat in my head.
This was the last antenna video on this channel for a moment. Other topics are waiting...
I also purchased the N1201SA so I can fine tune my 915 MHz LoRa antennas. Your video is great.
KC2ORP
Thank you!
A very informative video, but I listened to the "power transfer" explanation at 5:20 to 5:45 minutes into the video multiple times to try to make sense of what was said. I concluded that there was a misunderstanding between the phrase "power transfer" and "current flow". The current flow is maximum at dc because the reactance of the inductor vanishes there. The current flow is also maximum at infinite frequency because the reactance of the capacitor vanishes there. But the "power transfer" also vanishes at both ends because the voltage drops to zero there, and power is the product of voltage and current. Power transfer is maximum at resonance precisely because that is the frequency at which there is an optimum compromise between voltage and current.
Maybe you are right. I assumed the circuit is in series (comparable with a cable) and assumed, that, if I have no voltage across this "cable", 100% of the power is transferred into the load. Your view is probably a little different.
Thanks for your reply. The video describes a parallel LC combination, which is why the current is maximum at the frequency extremes. There is no voltage drop across the LC combination, and all of the power is disastrously deposited in the source. If it had been a series LC, then there would be no current at the extremes, and again no power transfer to the LC combination at the extremes. In either case, maximum power transfer occurs at resonance, n'est-ce-pas?
The net effect is that the LC combination, which is simulating the antenna, gets maximum power transfer at resonance. If it is a parallel combination, then the source is in danger of being destroyed by too a high current at the frequency extremes. If it is a series combination, then the source is in danger of being over-voltaged (a factor of two, and maybe more).
Again a very good video! Thank you very much. I ordered a N1201SA this morning via your link and hope, you'll get your "fee".
Thank you for your support! I hope you will like it.
Your videos are always interesting and I always learn something useful.
Thank you!
Great video and simple description. I have a PS 100 model of it and I find it very useful for tuning the POTY antenna for QO-100
Did you see my videos about the QO-100?
One of the best videos of 2018. Thank you for explaining things I’ve always wondered about my whole career.
Thank you for your nice words!
Great to the point tutorial for people who know nothing about smith charts
Thank you!
You make very nice videos, for me some parts are review but some is new, kind of to radio stuff but have done electronics for years. Thanks again for sharing!
You are welcome!
After watching this video I ordered the N1202SA. And Sir, You were right, it is a great tool! I have tried to find an adapter that could be used to measure the IPX connector small antennas. Can You give some tips where to find adapter that makes it possible to test antennas having u.fl and IPX female connector?
You are doing excellent job helping people to get in to electronics. Oh, and did I already mention that I love Your videos ;-)
You find them on Aliexpress (IPX SMA adapter). I ordered 2 different and one was not good. But I do no more know which one was which :-(
Such a good tutorial,... I bought one for analysing my home-brew antennas I make for mobile coverage & repeaters.
.
.
You are not alone,. These cheap VNAs became quite popular. And very handy!
@@AndreasSpiess - Good day, and apologies for not responding to your kind reply above.
- Did you ever measure the FINAL cut length of your TUNED antenna ??? >82mm or
Informative and entertaining! Just ordered a NanoVNA -H 4" for optimising my RX antenna's that have to be stealth! (Wife, LOL)
You will love it. Make sure you watch my NanoVNA video before you start ;-)
Another, possibly less expensive, way to do it is in reverse using an RF spectrum analyzer; set your transmitter to output a constant signal, measure the received signal, and trim the transmitter antenna until you get the best result on the spectrum analyzer. It could be argued that this is even more useful because the nature of your overall project design can greatly de-tune your antenna, and this way you can visualize what works best for your specific needs. I am not ashamed to admit I have made commercial products using this approach, as simply designing an antenna to make a VNA happy does not tell you anything about how that antenna actually performs in-circuit, next to other parts, inside an enclosure, etc.
I would not agree that a VNA does not tell you anything in the situations we generally use (the antenna is outside the case).
I used a similar method you propose also in a video (only on one frequency). It is dependable if you are able to put the antenna at the place where it stays, but also creates a little more effort. If you move the antenna you have the same issues as with a VNA. Another problem could be the law if you want to scan larger frequency bands. BTW: Where do you get your Spectrum Analyzers for less than 150$ ;-)
In my case I virtually always use an antenna that is inside the enclosure, which does cost me a little radiated power but keeps the design small and clean (especially good when my project is to be used by non-technical people). I did not mean to suggest a VNA has no use, just that it cannot tell you how an antenna performs "in place". Most SDRs cover the necessary frequency range, and some of them are shockingly inexpensive (although I do use a $300 handheld spectrum analyzer, the "RF Explorer"). I forgot to say that I really liked this video, and think that this is of GREAT value to new engineers who are understandably afraid of the RF dark arts! :)
"like a good politician, if a method does not work, we just use more of it"
HAHAHAHA!!!!!
It is a little like an Englishman trying to speak Swiss. English Loudly, then more Loudly.
Spot on, we see that every day now.
Like previous video on antenna, this video is really useful. I'd like to thank you Andreas for sharing useful videos.
You are welcome!
I can only confirm: I own one and I love it - so much better than calculations ;)
Thank you for your feedback. It is very valuable for others
This video is awesome Andreas,
Just wondering who are those 6 jealous people which dislike this wonderful video?
1.4K(up to the present) is much much bigger than 6 !!!!
Probably their antennas are not adjusted exactly to your channel frequency !!!
I always get a few thumbs down. I have to live with it...
I find the N1201SA analyzer very usefull. I have one. I would recommend it too. I would prefer a good spectrum analyzer with larger bandwidth but I cannot justify the cost.
These devices are still quite expensive. I only bought one because it was a long-time dream...
Hi,
thanks for the video, which introduced the N1201sa to me. I looked for further information and was astonished to learn there are not many information at all, beside of a few TH-cam Videos.
E.g. There are many different models now.
N1201sa the one you introduced
N1201sa+ with an extended frequency range down to 37MHz
N1201sac which adds a ttl serial port for communication.
Then there seems to be a successor
N2201SS, which seem to add a TX port, but Infos on that is very spare and most is misleading, e.g. the description of the N1201sa is given albeit the N2201SS is for sale.
No infos whether different versions of the N2201 exists.
Finally some sellers offer a N2061SA which also seems to offer a TX port for a frequency range from 1.1 MHz to 1.3 GHz. Albeit no more infos can be found. Esp. Further spec differences between the N2201 and the N2061 would be interesting.
All Infos so fare are from Chinese sellers on the usual platforms. We all know how much we can trust those information... Heck, I couldn't even find the original manufacture homepage. No comparison tables, no reviews for the later two models. Nothing... even in Chinese information on the internet are rather spare.
Much interesting would be a miniVNA tiny vs a N2201SS comparison, to get an idea about the performance in this price range. Both follow different ideas about usability etc. but at the end those might be what a hobbyist is looking for.
Maybe that is a good idea for a part two of this video. ;)
I cannot Test VNAs. The only I tested with a colleague is the one I showed. The mini seems to be ok and the software works. For the moment I do not plan an additional video. I use the small one for my antenna tuning and the miniVna if I want to learn about Smith chart.
Well, I understand this. Was hoping that others can provide more information about all those different models.
Identifying the original manufacturer would be a good start already.
If you would have to decide for one, the N1201sa or the minivna tiny, which would you give a preference?
Well explained.. Always your style of presentation is easy to understand and very useful for beginners..
Thank you for your kind words!
Thank you, very useful info on Antennas. I'd love to learn what are the things to be considered if you soldered a LoRa module to a PCB. So then routing a track from LoRa module to the antenna. I'd imagine you could make quite a mess.
Keep the distance between the module and the antenna short... Maybe you google about the dimensioning of transfer lines on PCBs.
Great video as always! I was really hoping you were also going to show the insides of the N1201SA VNA in "Don't turn it on, take it apart!" fashion.
I would never take it apart. The risk is too high that it does not work anymore. That would be a catastrophe for my relation to this small device ;-)
For your info: It consists of an ADF4350 and a SA612A mixer plus the usual STM processor and charging circuits.
I really enjoyed this as well as quite a few other videos you have produced, thank you.
Glad you enjoyed it!
1:14 I'd say the ground plane antenna has been the #1 most common antenna type in the world for over half a century, there's been one on almost every car and truck ever made that came with an AM/FM radio for well over the last 80+ years and by 1946 there were an estimated 9 million AM car radios in use and currently over 1 billion estimated on the roads today not counting the ones no longer being used. Mobile device antennas might have changed that though.
If you call all vertical antennas "Ground Planes" you are right. Often, the word "GP" is used for 1/4 wavelength radiating elements. Then An AM antenna would have been quite long ;-) That's why they often were loaded/shortened with inductors.
@@AndreasSpiess no, not ALL vertical antennas are GP's, there are vertical dipoles after all... But in the case of vehicles we are not typically talking about a "radiating" vertical element like we would expect for a ham "transistor" radio that can transmit too as well as just receive. Vehicle AM/FM radio antennas typically only have to "receive" which is much more forgiving and can be MUCH smaller fractions of a full, half or even a quarter λ to work...
@@AndreasSpiess I would even imagine "some" mobile radios could be considered a GP antenna too because your body acts as the ground plane. With my cheap UV-5R radio my hand capacitance acts as either the bottom of a dipole or a ground plane depending who you ask and the same could be said of other mobile devices too. What is your opinion on that matter Andreas?
Eres lo mejor que le ha pasado a la Ingeniería Electrónica!!!
Thank you. Maybe you watch also my video about the NanoVNA...
Today I got my Nano Vna and Joe Smith mentions you in his video!
VNAs are great! Enjoy.
You best video so far! That explained a lot! Good work! Now the logical next step is to explain impedance even deeper.
This was the last video on antennas for a while. There are better channels for that if you are interested in antennas. I want to keep this channel broad, and not trivial, but not only for specialists.
Please note that, for low power transmitters, it's often worthwhile to design it to attach directly to the antenna. This removes coaxial cable losses totally. If you need to get data some distance to the transmitter, a data cable is much cheaper than coax at any length.
I completely agree, especially for high frequencies.
I see that you are very close to explaining the Smith chart and it's usefullness :-) But it would be hard without complex impedance :-)
Very nice video!
This is why I shortened the video. First, it was in. But too complicated...
Great tool, I am wating for one that can measure 5.8GHz for FPV so that I can get a better idea why some of my penny antennas are doing as good or better than some commercial ones. BTW you have an interesting last name, makes one think.
I am sure we will get 5.8GHz devices one day.
Very nice, I've had this thing in my wishlist for about a year now. Guess it's time :)
Enjoy!
The best Andreas video in my opinion... and yes, we must keep politicians in the resonance regime so that they can cancel themselves... Is there a video of the VNA you show at the end? keep the good work!
I have no video about it but you find some other videos.
I'd not have trusted these things without your recommendation. Thanks for taking the risk on our behalf with such a wonderfully qualified response. Does this mean you have RAK troubles? :)
The RAK works now. I had a wrong board from Charles. Now I am trying to compare the performance of the two gateways. Not as easy as I thought...
No I've been playing with adding GPS and running things in Docker - now there is a whole track of video possabilities (have the antenna tester on it's way - I bet China is empty of the things after your commendation).
Real life experiments are much more fun than theory.
Do I right or wrong in this respect?
Yes right. The theory can be a bit dry, but to see it in real life and discover the result as you go is like a eureka moment for the viewer when you see it.
Hello Andreas!
Really amazing video - it really deserves three thumbs up! It help to solve problems people usually does not know it exists at all. By the way: do you think it is worth to invest additional 50 EUR into newer model N2201SS?
This is not a newer model, it has more features. But I do not know it (ant the software coming with it). I bought the miniVNA instead.
Just for antenna tuning, I cannot imagine you would see a difference between the two because you do not need the second port.
Andreas, bal-un, "bal" as in bal-anced & "un", as in un-balanced, not bal-oon ;)
Also, frequency of resonance or resonant frequency :)
Parasitic capacitance or parasitic inductance, not " built-in".
Another interesting and useful video!
Thank you.
Thanks Andreas, as usual, your videos are excellent and will save us lots of RF-hassle!
You are welcome!
An awesome video, Andreas. You have demystified the dark arts of antenna tuning. Northshorepx says it all and I support all he says.
Thank you!
Hello Mr. Andreas! Excellent video very pleasant to watch and informative, but remains a question, what's the difference between N1201A vs N2201SA? Is there other feature available?
As a suggestion, could you please do some antenna construction videos? Thanks in advance!
As I mentioned it has two ports and also a Serial connection. But I did not look at it and if the software is good.
Andreas -
Excellent informative video.
But maybe i misunderstood one point. You said "these VNA's must br calibrated using these three items", but i can't figure out if you mean if you buy the n1201a you will have to calibrate it, or if you mean if you want to calibrate it.
You should calibrate it from time to time.
I recommend a new book called "Principles and Applications of Vector Network Analyzer Calibration Techniques" !
Thank you for the recommendation!
At 12:00 you said you found no significant difference between the two analyzers. If I am reading the units correctly, one is showing an S11 of -28dB at 868MHz, the other is at -20dB. If this was for the same antenna then I would say that is a significant difference. But yeah great bang for the buck for this little thing and great video overall.
You are right (even if both results show excellent antennas VSWR 1.2 vs 1.1). We did not focus too much on the absolute values for the antennas because we did the measurements inside on a bench. There were some differences, also because of the setup. Especially with antennas. We more focused on the relative curve, which, in our judgement, is sufficient for antenna optimization. But we also measured a filter which removed most of the environment variables. And there the results were good.
@@AndreasSpiess you should have dug a little deeper into this unit, as it should be the center of attention, and it's filled with information and values and would likely be a helping hand to many people to explain what many of these values mean alongside the graph for these values.?. as the voltage standing wave ratio, pretty on call with the meaning of that aspect.
and yep at the sub 90 bucks (USD), they seem to go for, its a nice tool, definitely.
imgur.com/a/3kHMlnW
If you have another video on this unit that goes more into actual item-details & features and meaning' or your familiar with one that tests this unit more thoroughly' please share..
You did not recall his complete statement. You left out "for our purpose." Shame on you
Hey! Look who it is.
A difference of 8 dB sounds like a lot, but is it in this case? It is important to remember what exactly it is you are measuring. S11 is reflected power or return loss. So S11 = -20dB means that 1% of transmitted power is coming back from the antenna or load, and -28dB means that less than 1% is coming back. Is that a big difference, or in fact any noticeable difference at all in how your antenna system performs? You may see a change at that level by bending a coax feed cable just slightly more or less. For this price, a VNA measurement in UHF band to 1% in power ratio seems pretty good to me.
WOw!! Wonderful review! BTW, the aliexpress link shows a large number of devices most of which have colored numbers on the display and one that show the graph like you have in the video. Which one should I pick?
Look at the name N1201SA (from AAI). You need also a calibration set if oyu do not have one.
Hi and thank you for your very interesting video regarding antenna measuring and the VNA. I se that the vendor also have seveloped the N2201SS VNA with two ports.
Would you consider testing and reviewing the N221SS extra features as well? In addition to power meter, it is supposed to support some extra measurement features. S21?.
With so many poorly manufactured antennas for RC and FPV hobbyists, this kind of knowledge and tools are of great interest and benefit.
Thanks!
Kind regards
Torgeir
I do not plan to test the N2201SS as most of my viewers do not need two ports.
Excellent presentation!
Now we look forward to your review of the MiniVNA Tiny clone. I may be tempted to buy one if it is any good. I have the 1st. gen MiniVNA and are quite satisfied with it, except that it does not go higher than 180MHz. So I would buy the one you show there if it is a tool and not just an expensive random number generator.
And did you really think you would get away by showing us an RMA and a RMA-RP in the same picture with no mention of it? Mate those two and measure the WSWR through them! It should be pretty high. ;-)
1. I have no plan for a VNA review for the moment.
2. SMA connectors should be 50 ohms (and they usually are).. So two connectors in series are not too critical.
Thank you Andreas ! 👍👍
RF has always been "black magic" to me ...☹️
I wich i had your knowledge about antennas !
You are welcome!
Thanks Andreas, awesome video as always. quick question .. can I change one of those common 2.4GHz antennas to operate on 900MHz with the help of N1201SA?
Not easy. It is Mitch too short.
Excellent! I love the lesson plan and summary. It helps reinforce learning.
Great to hear! Thank you.
Thanks, very helpful and still affordable tool! Thanks for sharing. There are so many antennas on aliexpress or eBay and you never know what you get. This tool helps to sort out the non reliable vendors and to find the well matched antennas.
In my understanding you can see if the antenna is matching. But how can you find out something about the gain and directionality?
With the setup I showed in the last video
Thanks, I think the #188 Video.
I gave this video three thumbs up. I was going to make it two thumbs up, but the second time I clicked the thumb it turned off the "Like"
:-)) Thanks!
It's one or nothing here.
5 Likes.
It's fine as long as you give it an odd number of likes (1, 3, 5...)
Really excellent teaching here, learning points well made and useful information. Thank-you.
You are welcome!
brilliant. We just got one of these for our Maker Space!
Good!
thanks a lot Andreas, this video was awesome. please consider doing a video on cables and connectors like SMA, RP-SMA?
This was the last antenna video for a while. I have many other topics waiting...
Excellent video. I also have china antennas which work correctly only when the plastic cover is removed. Do you think the designers were unaware of the dielectric effect ? Abit like the antenna problem on one of the earlier iphones ?
The palastic shifts the resonance frequency (as you write). It has to be taken into consideration while trimming the antenna.
@@AndreasSpiess
Is this due to the polymer lowering the velocity factor?
@@MountainParameters I do not know 😞
@@AndreasSpiess
When we used dual wall adhesive heat shrink to ruggedize a Smiley 5/8 wave SAR antenna, it decreased the velocity factor and the result was we needed to trim an extra 2mm (as compared to the same tune point for the stock Smiley with no heat shrink) in order to optimize the best SWR and impedance for our target tuned frequency.
Einfach super! Ich habe schon lange darauf gewartet.Vielen Dank!
Bitte, gern geschehen
Note that using springs and other "gimmics" to tune the antenna will give false results. The radiation resistance of the antenna itself must be 50 ohms, not a combination of gimmics plus the antenna. The actual signal radiation can be significantly off even if the apparent resistance is a nicely matched 50 ohms.
I am not sure I understand. With the VNA I only check of the power is radiated by the antenna or reflected back to the transmitter. I cannot tell anything about the radiation pattern nor the gain of an antenna. But reflected power never is radiated...
I am one of your subscribers, BTW :-)
I now have one of these analyzers thanks to your video and recommendation. It's actually the two-port model so in the future I may be able to do more than just S11 measurements. However, I have a mystery.
The VNA works well for my custom made antennas, and shows many purchased ones are crap. However... I have a length of coax that identifies itself as RG-58A, but feels far more flexible than I'd expect. While I don't intend to actually use this for an antenna as it's too lossy at 915 Mhz, it seems to show a constant VSWR across all frequencies from the lowest I can go with this unit up to the maximum. It doesn't matter if I short the cable end or not, and I have tested the cable for shorts between the center and shield, and there are none.
I do have an older model MFJ analyzer that can go down to at least 1 MHz, so I'll likely test it on that later. However, this is either an expected yet shocking to me characteristic of this long cable, the cable is defective, or the tool can't cope. In this case, I suspect it's the former -- all the signal IS being absorbed, so the S11 looks AMAZING as there is no reflected power, the VSWR is AMAZING as there is no reflected power, and the impedance is spot-on.
I cannot tell it from here. But it would be interesting if any power leaves the other end... To prove your theory that all power is lost.
It is anyway a strange behavior.
Andreas Spiess agreed. I’m not sure how I’d measure that though. Perhaps just using a signal generator and oscilloscope showing inputs and outputs.
AFAIK the two port model should be able to measure S12 or S21?
Andreas Spiess indeed it can. Small power only of course.
The bigger signals can be done using attenuators, as usual.
Again another useful and interesting video. So..do we get treated to the mini vna review next Sunday? :)
No. This is the last video about antennas for a while. I have other topics waiting...
Great video and the MiniVNA Tiny looks like exactly what I want as it covers such a wide range of frequencies shame it seems like its no longer available. Where did you get yours? It seems a little different in the metal case so maybe you found an alternative supplier?
By the way can you also do a review of the even cheaper MR300 (based on SARK 100) which is good up to 60 MHz. Not good for these antenna's it's true, but for us HAM's... :)
I got mine from the link provided. Maybe you search on AliExpress. Or the supplier just was sold out for a few days?
I will not cover a low-frequency VNA because I have no use for it. But there are a few amateur radio related channels (e.g. WA2AEW) which are better prepared for such a review.
Andreas Spiess I did a search as suggested and although it seems the original supplier doesn't sell them I found a supplier of an updated device based on the original. Thanks for the reply. 73s
wonderfull video to understant a little more of the magic subject.
Plus a free introduction to political understanding of switzerland.
Great
Being very concerned with 5.8 Vtx and antennas, do you know a similar version of a VNA up to 5.9 GHz ?
No, I do not know one.
really amazing tutorial, congratulations and thank you very much!
Thank you for your nice words!
Nice timing. I ordered one a few days ago already 😁
Enjoy!
i compared it with some expensive analyzers. it seems quite accurate. really interesting for such a price.
Thanks for good video! You adjusted length of a portable antenna while it was connected to the VNA. Does case of the VNA affect antenna properties? I mean once you disconnect that antenna from the VNA and connect that antenna to a radio, it might not match exactly the same. If radio case is bigger or smaller than VNA case or if it is made of different materials the antenna will match differently to the radio.
Every change changes the properties. So you can try to emulate the situation as good as possible. You see this also if you touch the SMA connector while you measure with the VNA
@@AndreasSpiess Got it. Thanks for explaining.
Hi by cutting the ground plane you're simply changing the feed impedance. Not the frequency. So when you cut all of them, you have baad swr.
You are probably right. Sometimes there is some interaction between the two.