437 How to Use a Vector Network Analyzer (VNA) to Test Antennas

[@mortalwombat5811]

I've watched half a dozen videos on this subject over the last couple days, and I really wish I'd watched this one first. It's thorough, approachable for a layperson, and well organized. Thank you for this.

[@AndreasSpiess]

Glad you enjoyed it!

[@damny0utoobe]

Its becoming an antenna classic on KZbin

[@AndreasSpiess]

That was my plan ;-)

[@nflgun]

This is by far the most concise & easy to understand video on both the VNA as well as the Smith chart. Exceptional presentation, thank you.

[@AndreasSpiess]

Thank you for your kind words!

[@davideisenberger6197]

“EXCELLENT presentation!!” Thank you!!

[@davideisenberger6197]

I agree with you!

[@fillphrench]

Thanks, Andreas - this is extremely useful. These devices usually arrive with no instructions, and certainly no theory of operation.

[@AndreasSpiess]

You are welcome!

[@asperheim]

Possibly one of your best videos. Truly excellent.

[@AndreasSpiess]

Glad you think so!

[@asperheim]

@@AndreasSpiess the pleasure is all mine.

[@MyTube4Utoo]

*EXCELLENT* I just received my LiteVNA a couple of hours ago and wasn't finding a good, thorough video explaining it's operation. I generally knew what it did, but now I have a much greater understanding. Thank you.

[@AndreasSpiess]

Glad it helped!

[@PilotJimmyJ]

Excellent video. I just purchased a VNA and I have no idea about how it works - although I should. Your explanation really helped me understand how it all works.

[@AndreasSpiess]

I am sure you will enjoy the device!

[@veedonfleece3694]

Thank you Andreas. Such a clear, general intro to VNAs and their use. Well done. As an RF guy, I was not aware of the NanoVNA's existence on the market. This will hopefully encourage makers to explore even more.

[@AndreasSpiess]

Indeed it already had a huge influence on HAMradio. Many more people started to build antennas and baluns, for example... And many Makers started at least to test their antennas and understand a little more on how they work.

[@AndreasSpiess]

During my summer breaks, I play old videos (as mentioned in the intro). So the prices shown in the video are from before the pandemic

[@nigelman9506]

This is a double like, you explain things perfectly, it gives me the confidence with my VNA, I used it on my homemade multi band aerial mast, saves time tweaking the SWR on each aerial before it goes up above the house, many thanks again

[@AndreasSpiess]

Glad it helped! Indeed, these are valuable devices.

[@aronhighgrove4100]

I hadn't complimented you on your nice presentation, since sometimes we think it's obvious or a thumbs up is enough. But especially the capacitor tuning to show how it changes the trace in the Smith chart is very helpful to remember it. Thank you. For those who want to make tunable inductors: they can be easily made by having some stiffer paper wrapped loosely around a ferrite rod, and winding the coil on this stiff paper. Then moving the rod while holding the coil still (or vice versa), will affect the inductance.

[@AndreasSpiess]

Thank you for your kind words!

[@ethzero]

Just purchased a NanoVNA (3.6) from AliExpress and *for a complete novice* your video, as many others have made the point, was extremely useful in understanding not only the common operations but the unpinning theory. I'm in the process of setting up local Meshtastic nodes to hopefully bridge two clusters of nodes so your other videos covering LoRa and antenna will be very useful I'm sure!

[@AndreasSpiess]

Glad I could help! And enjoy Meshtastic.

[@ishwarm5842]

I have been enjoying your content a lot. You break down all your topics in such a simple and clear way. Thank you Andreas!

[@AndreasSpiess]

Happy to hear that!

[@_adamalfath]

Thank you for the explanation. Please consider posting more this easy-to-digest RF topics in the future while using relatively affordable gear. Practical stuff like this antenna quality measurement, simple impedance tuning like pi-circuit on ESP32 antenna trace, etc.

[@AndreasSpiess]

I have a second channel for RF stuff. This one is more for Makers...

[@bayareapianist]

@@AndreasSpiess what is your 2nd channel's name?

[@AndreasSpiess]

@@bayareapianist HB9BLA wireless

[@doco6186]

Hope you're having a great break. Please consider listing possible videos to be shown while on summer break and letting your followers vote on which ones to repeat. I always enjoy and learn from your vedeos. Thanks

[@AndreasSpiess]

Thank you for your suggestion. I do not want to spend too much energy on these videos. :-( But you can suggest one if you want.

[@BerndFelsche]

Thanks for the repeat. Some things are worth repeating. Repeating important things is worth the time and effort.

[@AndreasSpiess]

I agree. In addition I see from the comments that many of my current viewers were not around then. For them, these videos are like new ;-)

[@skydivingcomrade1648]

As always a pleasure to watch and learn from your videos

[@AndreasSpiess]

Thank you!

[@TowerGMLtdInfo]

Thank you the detailed explanation of my NanoVNA.

[@AndreasSpiess]

You are welcome!

[@SatonlineGmbH]

Great video, thanks! Reliable VNAs are hard to find, so this was very helpful. Keep it up

[@AndreasSpiess]

Thanks, I am glad you found it useful!

[@Jyaazu]

This is very useful and entertaining video, Good job Mr. Spiess, They have such Circuit to match the impendance, This is an Antenna Coupler or Antenna Impendance Matcher, This main job is to Match the Impendance and Phase Shift of Waveforms, This mainly use for Ham Radio Antenna to Improve the Radiated RF signal to the Air

[@AndreasSpiess]

Thank you. And you are right, these devices exist. But still I prefer to have a matching antenna if possible. It does not have the cost and loss of a tuner (I am a HAM operator ;-)

[@Jyaazu]

@@AndreasSpiessI love to watch a video on ham radios for beginners especially on your channel

[@jakedillingham]

Hi there thank you very much for your video. I’m heavily dyslexic, this tutorial is perfect, very pictorial. Thank you.

[@AndreasSpiess]

Glad it was helpful!

[@TheTrinityDawn117]

Excellent video that explains the basics of using the NanoVNA, thank you!

[@AndreasSpiess]

You are welcome!

[@R73CH]

Well done. I will be recommending this video to my students as an introduction to Very High Frequency Measurement course. One note: the Thru elements should be (ideally) lossless and of zero length, therefore the one you show at 15:36 will not work, especially if the phase measurement is important.

[@AndreasSpiess]

I do not do a lot of through measurements. But I thought this method would work if I connect the DUT directly to one port and use the same cable to connect the DUT because the effect of the cable should be removed through calibration. How is it done correctly?

[@edieharo4186]

Thanks!

[@AndreasSpiess]

Thank you for your support!

[@lektor0815]

Very awesome explanation. Thank you. I just got the nanoVNA. 🙏

[@AndreasSpiess]

Enjoy!

[@newYorkStories]

Thanks for this! I am currently studying for my Extra license - this video made me finally understand Smith charts! 73 und Grüezi

[@AndreasSpiess]

Glad it was helpful! And good luck with your test.

[@AbuSous2000PR]

The BEST tutorial on VNAs; really exhaustive! Many thx again man

[@AndreasSpiess]

Glad you liked it!

[@k6aaq64]

Speaker presents very well and is easy to follow. Nice work, thank you!

[@AndreasSpiess]

My pleasure!

[@gnormhurst]

I appreciate that you keep mentioning that it only ever measures amplitude and phase. With all the SWR, return loss, Smith, LogMag display options I can see where people might think it makes a whole bunch of unique measurements. Nope. Just amplitude and phase.

[@AndreasSpiess]

It is as it is. Plus some math, of course ;-)

[@RoguePlank]

Omg the tiny hand, bless

[@AndreasSpiess]

:-))

[@spacecase0]

One of my best friends is a ham radio operator that taught me about radio frequencies. I'm not quite sure if he's from switzerland, but I suppose I met him in high school where accents weren't really a thing with anyone, at least after a few years. I remember his girlfriend that absolutely was from Switzerland. She vacuumed up ants and thought they could get out afterwards, I was really sad to tell her that they couldn't escape. Anyway, years later I met these people in different scenarios. And certainly not complex scenarios like the vector Network analyzer. I've got a tiny network of vector analyzer. It is quite fantastic. But most people don't realize what it's capable of or what it is sensitive to receiving.

[@AndreasSpiess]

This Swiss lady seems to have made an impression on you ;-) Indeed, we have lots of women who are afraid of small animals like ants or spiders...

[@mortenlund1418]

One of the best videos on the subject. Thanks!!

[@AndreasSpiess]

Glad it was helpful!

[@ceeb830]

15:18 you stated that you connected the short to the vna first but when you did so you clicked on the “open” option. Am I correct in assuming you are supposed to calibrate it starting with open then short then load?

[@AndreasSpiess]

The sequence of SOL does not matter. But my video cutting was wrong.

[@adjudant-chefwillsdorff6037]

Thank you for explaining vna in a such concise video. However, as already identified in comments, it seems impossible to buy a such device (3ghz) for about 50$. We can find only 900mhz devices for this cost (plus VAT and delivery). 3ghz are quite more expensive. Be careful with some copies which don't have results as good as provided by the ordinal one. However the cost (including VAT and transportation) jump to 250 $ for such devices. Regards

[@AndreasSpiess]

As mentioned in the intro, I play old videos during my summer break. This video was made before the pandemic...

[@Anthony_Matabaro_3D_360]

Hi Andreas Spiess, another great video, thank you. The link to your other KZbin channel does not work sir.

[@AndreasSpiess]

Thank you. Now it should work...

[@johnkweber1]

Excellent video. Thank you for the time you take to make such awesome videos.

[@AndreasSpiess]

Glad you like the content. Like that it is worth the time it takes to crate ;-)

[@DrSambernardo]

Incredibly good content! Thank you! just one question from my side: how would you make a PCB antenna characterization?

[@AndreasSpiess]

Similar to any characterization. However, here, the atachment is more difficult than if you have a connector. Usually, they solder a short cable to the antenna.

[@TheChalansillo]

great video, clear explanation, I fear no more... but I should

[@AndreasSpiess]

Indeed, the devil lies in the details ;-)

[@UV-NIR-Thermal]

Thanks for explaining this so it's understandable.

[@AndreasSpiess]

You are welcome!

[@nmidu]

my hero! greeting from argentina ! good info as allways sir

[@AndreasSpiess]

Thanks for watching!

[@ernestofigueroa9278]

Thank you so much for this video. As it happends i do have an nanoVNA and have allways been confused why all my antennas are so bad according to the VNA and i now understand why. I use adapters to a PL connector. Question, How do I calibrate so I can meassure my antenna with an adapter and a cabel? I would like to meassure the antenna i have set up on the roof so i have around 10m of cable and then an adapter from PL to sma. Do I have to disconnect the antenna before calibration so i can determin the zero-point? again, thank you so much for all your videos, very much appreciated

[@AndreasSpiess]

Calibration is always done with the respective calibration set at the desired reference level (either at the antenna or at the transceiver end of the cable. You decide what is important. If you want to check the antenna, measure at the antenna.

[@josediaz2643]

Thank You so much for a great and direct explanation!!! Much Appreciated!!!

[@AndreasSpiess]

You are welcome!

[@aronhighgrove4100]

10:44 capacitance and inductance do not change, but the impedance changes/is frequency dependent.

[@AndreasSpiess]

You are right!

[@science4allworld587]

Excellent helpful and informative video as usual... thanks.

[@AndreasSpiess]

Glad it was helpful!

[@karlmatthias2698]

Excellent explanation as usual! Thanks for making it easy to understand

[@AndreasSpiess]

My pleasure!

[@DimitriVolkmannSY]

Great video, thanks! Now, if I have an outside antenna with let's say a 20m cable getting into my shack, how do I calibrate to measure this antenna?

[@AndreasSpiess]

To check the antenna, you chose the reference plane at the antenna connector. If you want to protect your transmitter, you choose the reference pane where you plug the cable into the transmitter.

[@rilosvideos877]

Thank you very much for this smart and comprehensive introduction video - much appreciated! I just consider building myself a simple VHF/UHF dipole antenne (or J-Pole antenna) for a baofeng ham radio. I just want to test the difference in recieving (and transmitting) concerning distance and quality. There are some nice DIY projects to be found in the web. Do you still consider a NanoVNA necessary for tuning the antenna to optimum? Is it even possible to build a good antenna without checking the values? I think the 50 $ are neatly invested for such an elaborated tool - but i never needed it before in my life. (but i never built a diy antenna and questioned it quality before 🙂)

[@AndreasSpiess]

Of course you can build a good antenna without a VNA. But how would you know?

[@rilosvideos877]

@@AndreasSpiess Thats what i mean: just by chance 🙂

[@mikez484]

If you calibrate the vna, choose the frequency range, do this for a number of ranges, and save each calibration and range for a future check, is the calibration still good on each separate range?

[@AndreasSpiess]

The calibration should stay ok over time. Each is good for one reference plane and one frequency range.

[@uberschall_4714]

vielen Dank. Sehr gut erklärt. Wie ist das mit aktiven Antennen die einen Verstärker mit eingebaut haben? Kann ich die selbe Messung auch mit der eingebauten Elektronik machen?

[@AndreasSpiess]

Im Prinzip ja. Die Resultate müssen aber anders interpretiert werden weil sie nichts mit der Antenne zu tun haben.

[@uberschall_4714]

@@AndreasSpiess vielen Dank. Würde mich freuen, wenn du dazu mal ein Video machen würdest.

[@ParadoxTransistor]

Excellent and useful information, very good explanation as well!

[@AndreasSpiess]

Thank you!

[@davidm1635]

appreciate your distribution of knowledge!

[@AndreasSpiess]

:-)

[@Pootycat8359]

12:50 In the U.S, hams and CBers almost always call it "SWR," while broadcast engineers use "VSWR." That's also how the RF output meter (power & VSWR) on a radio or TV broadcast transmitter is labeled. All this is not important, but if you're discussing radio with someone, the term he/she uses gives an indication if the person is just a ham or hobbyist, or has experience in the broadcast field.

[@AndreasSpiess]

I agree.

[@craiger953]

Excellent presentation!

[@AndreasSpiess]

Thank you!

[@SeAfasia]

Ga Andreas tks for excellent videos...the vna is a must have tool ..73

[@AndreasSpiess]

Indeed. One of the best inventions. Particularly because they are so cheap by now.

[@SeAfasia]

@@AndreasSpiess compare it with an expensive VNA take same results....best money give ebay ever ...73

[@AndreasSpiess]

@@SeAfasia I did this a few years ago when the first device appeared. The results were ok for hobby usage.

[@rojirrim7298]

Hey Andreas! Thanks so much for the video, insanely good. I got a NanoVNA 2.2/SAA-2 like the black one on the thumbnail, and I've tried as you have, to measure a 144/430MHz antenna. Unfortunately, the signal is extremely shakey, and touching the NanoVNA, or the antenna, or even putting my hand near the antenna, changes the valleys of the SWR by as much as 10MHz up and down. Is this normal behaviour of antennas, is my NanoVNA broken, or am I doing something wrong? Thanks a lot

[@AndreasSpiess]

That is how RF behaves. Use it to measure a fixed antenna and it should not happen.

[@rojirrim7298]

@@AndreasSpiess Thanks so much for your comment! Greetings from Spain! Additionally, I will say that, after 2h banging my head against the desk, and finding some answers on forums, by holding the NanoVNA with my left hand, and holding the Antenna next to my head emulating the position of the walkie-talkie, I can take a fairly stable measurement that generated SWR precisely at 144MHz and 430MHZ, so that was an interesting experiment. What do you think of this technique to more or less tune antennas for handheld devices? :)

[@AndreasSpiess]

@@rojirrim7298 That is probably the best you can get.

[@jps99]

Great explanation of a very cool piece of gear, thanks!

[@AndreasSpiess]

Glad it was helpful!

[@davidpower3102]

Am I crazy or is the hand that points at things impossibly small?

[@davidpower3102]

Never mind… it’s a stick 🤦 😂

[@AndreasSpiess]

Indeed…

[@GiNodrog]

Brilliant and very informative video, thank you.

[@AndreasSpiess]

Glad it was helpful!

[@darylmorse]

That was very interesting. Thank you for sharing!

[@AndreasSpiess]

My pleasure!

[@hugopristauz3620]

excellent crash course 🙂

[@AndreasSpiess]

Thank you!

[@stevexiao1488]

Is NanoVNA a good tool for direction finder with an antenna? If so, do you have an antenna product to recommend for 2.4 GHz? Liked your video. Thanks!

[@AndreasSpiess]

A nanoVNA has nothing to do with direction finding. And I do not have a recommendation for antennas other htan testing what you get. Or buy from a reliable source like Mouser or digikey.

[@stargazer7644]

Nice video. My only complaint is it confuses precision with accuracy. Calibration has nothing to do with precision and everything to do with accuracy.

[@AndreasSpiess]

You are right. As a non-native speaker I do not know the difference :-(

[@stargazer7644]

@@AndreasSpiess Ah, no worries. Here's a quick guide to resolution, precision and accuracy. A meter stick with 10,000 (0.1 mm) divisions on its rule is higher resolution than one with just 1,000 (mm) divisions. But if the "meter" stick actually turns out to only be 0.9 meters long, it has poor accuracy because everything you measure with it is slightly wrong. Accuracy has to do with how close a measurement is to the actual value. When you calibrate a device, you're attempting to make sure the reading you get is close to correct. Precision relates to how close repeated measurements of the same thing agree to each other. A micrometer with a worn out gear train will be sloppy and will give you different measurements every time you measure the same thing. It has low precision. So in summary, accuracy has to do with how close a measurement comes to the actual correct value, precision has to do with how repeatable that measurement is, and resolution has to do with how many decimal places a measurement can be confidently made to.

[@flat-earther]

@@stargazer7644 okay thanks I appreciate your insight. BTW stargazer, have you become a flat earther yet?

[@stargazer7644]

@@flat-eartherImbecile trolls only get one reply from me and you just used yours up. Sorry.

[@flat-earther]

@@stargazer7644 BTW stargazer, what do you think about all gubments drawing a line around you and saying you are not allowed to leave?(Antarctic Treaty) If you don't know what I mean, read my about tab.

[@Maksim-Laika]

Thanks for the excellent video! I wonder is LiteVNA useful for weak LTE signal scouting and better external antenna positioning? Is it good as spectrum analyzer for 900-2700 Mhz band?

[@AndreasSpiess]

VNAs are, other than spectrum analyzers, not made for listening to external signals. So the TinySA would be the better choice

[@slonbeskonechen8310]

Great tutorial! Thank you!

[@AndreasSpiess]

My pleasure!

[@SantoArcidiacono-y3c]

Thank you. Very interesting and informative.

[@AndreasSpiess]

Glad you enjoyed it!

[@shanieboi86]

Absolutely new to antennas but have a decent understanding of electronics. Say you detect you need to add capacitor to your antenna at a particular frequency, how do you do that, in your circuit (if it's your board) or can you get inline sma capacitors and inductors?

[@AndreasSpiess]

usually they create PCBs for that purpose. But sometimes you can solder a cap to the antenna connector

[@VMoore-y2m]

Fantastic video! Thank you very much.

[@AndreasSpiess]

Glad you liked it!

[@JAKOB1977]

These VNA..they seems to also have quite few other testfeatures up there sleeve, that people use for other things.. do you have a video, on other usecases these newer TinyVNA can be used for. phase delay, various Smith charts jX/LC, Qfactor, Polar, Linear, REAL, IMAG, Resistance, Reactance, etc TDR, low pass impulse, and LP step, bandpass, window, signal gen... they are quite extensive. The current ones, also got quite a few more testpoints and seems to go up around 6G.

[@AndreasSpiess]

No. This is my only video about the topic.

[@EricWAtchesVideos]

In 4G and 5G wireless telecommunications we use the term VSWR all of the time. I used to work for one of the radio OEMs. even there we referred to VSWR or RTWP.

[@AndreasSpiess]

Good to know! Thanks.

[@KillerSpud]

How would i use a vna to determine if a torrid is good for baluns, ununs, or chokes?

[@AndreasSpiess]

You have to build the balun or choke and do the measurements with the VNA. The you see if your device exposes the impedance you expect.

[@TRETT1956]

Sehr gut gemacht - Dankeschön Werner

[@AndreasSpiess]

Gern geschehen!

[@zenzeni77]

It all went right above my head 😅😂

[@AndreasSpiess]

It is not easy, I agree. But useful to learn!

[@catalinalb1722]

Hello Andreas, I need to measure some loop PCB antennas for 13.56 MHz. I understand from the documentation that the reader works best with a 20 OHm impedance. This means I should use a 20 OHm resistor instead of 50 for calibration? Thank you!

[@AndreasSpiess]

Yes.

[@robertkras5162]

The Nano v2 links currently shows up not as $50, but as $88 on ali and $129 on Amzn

[@AndreasSpiess]

During my summer breaks I play old videos (as mentioned in the intro). So these prices are from before the pandemic

[@tester30466]

Keep in mind, these cheep VNA's use rectangle not sine wave to measure. That means 3rd harmonic is only about -10dB and 5th harmonic -15dB below the base frequency. I expect for devices that reflects harmonics totally and are well matched at base frequency S11 could get wrong figures around match frequency. For S21 I think an error should be visible for bandstop/notch and highpass devices. It will be interested, to measure some DUT's also on an expensive VNA and compare results. Fun fact is, the 3rd harmonic of 145MHz is 435MHz in the middle of the 70cm HAM band. I own a LiteVNA 64 (more points, more speed, more expensive, also rectangular signal).

[@AndreasSpiess]

You are right with the rectangular signal. I own a Keysight VNA and could do some testing. Maybe you contact me via X or Facebook messenger (or QRZ.com if you ar a HAM) to discuss the tests?

[@Professzore]

A correction. "it shows if the antenna is good or bad" is a common misunderstanding of antenna impedance matching. A 50-ohm high power resistor (dummy load) is EXACTLY 50 ohm, so it seems perfect on a VNA (or VSWR meter), meanwhile, it's a terrible antenna.

[@AndreasSpiess]

You are right.

[@W4TRI_Ronny]

I just got 3 LoRa modules and I'm watching the older videos now. Is there more to come on LoRa? Thanks!

[@AndreasSpiess]

Maybe...

[@w8lvradio]

My question is how to use it with the pl-259 connectors as commonly found in HF antennas to test them? Are there SOL calibrators for pl-259? 73 DE W8LV BILL (W8LV/VE3 prepandemic)

[@AndreasSpiess]

I do not know if there are PL/SO calibrators. You probably could make your own if you want. For HF, the length of an adapter is short and does not change the measuring results. These connectors usually are not made for high frequencies.

[@victorb22622]

Very very informative video

[@AndreasSpiess]

I am glad you think so!

[@shortwaverPL]

Thanks a lot for this!

[@AndreasSpiess]

You're welcome!

[@adbas6201]

I purchased one finally ! Do you think that the rfdemo kit is precise enough for 5 ghz ?

[@AndreasSpiess]

I never tried.

[@nileshkumar4606]

very good information thanks.

[@AndreasSpiess]

You are welcome!

[@ChaplainDaveSparks]

I wonder what it might do (if anything) to evaluate an EMI filter ~ _100 kHz?_ (There is a special _"ring wave"_ waveform that an IEEE standard _(C62,_ I think) uses to emulate power mains switching transients. I would only need a steady-state _quesstimate_ of the insertion loss. _73 de AF6AS_

[@AndreasSpiess]

NanoVNAs usually start at 50kHz. They can measure reflected (insertion loss) and "through" impedances (filters). But their domain is frequency, not time. Transitients are probably better observed in the time domain (oscilloscope).

[@alexanderwagner9524]

I have a ground plane antenna for ads-b on my balcony and a relatively short feed line (RG-8) to a box with a usb-dongle. When I build an antenna I usually connect a piece of coax with similar length to the antenna and tune it inside. Later, I put it outside and do fine tuning at the end of the coax, so I always measure antenna+coax in total. I try to get 50 Ohms by bending the radials and I get the lowest SWR into place by adjusting the length of the driven element. Is that the correct way if I calibrated without coax attached? In my mind, if the whole system is tuned at the point where it connects to the receiver, the antenna will be perfect and I don't need parts to compensate anything.

[@AndreasSpiess]

Coax cable changes the impedance if your antenna is not exactly 50 Ohms. I prefer the antenna connector as a reference plane if I want to tune the antenna. Only if I want to protect my rig I check the SWR in ma shack.

[@bryanrude8072]

With a quick search of Amazon I was not able to find a VNA with a upper range above 1.5Ghz that is much under a hundred dollars. Would you please add a link here or to your Amazon tools.

[@AndreasSpiess]

As mentioned in the intro I play old videos during my summer break. These prices are from before the pandemic :-(

[@N00kproof]

Hallo Andreas, danke für deine tollen und informativen Videos. Ich habe eine Frage, hat die Kunststoffhülle der Antenne einen Einfluss auf die Sendeleistung? In meinem Fall habe ich eine Antenne für 868 Mhz bei welches die Kunststoffhülle gut 1/3 länger ist als die eigentliche Antenne. Passiert da was wenn ich die Hülle auf die länge der Antenne einkürze? Danke für deine Hilfe im Voraus und Grüsse aus der Schweiz :D

[@AndreasSpiess]

Kunststoff so nahe an der Antenne verändert die Antennencharakteristik. Ich habe ein Gehäuse aus PLA (3D gedruckt) das die Antenne umfasst. Da verschiebt sich die Resonanzfrequenz um mehr als 5%. Ich passe alle Antennen mit dem VNA in genau der Situation an. Das Einkürzen hat vermutlich einen kleinen Effekt da sich die Änderung (ende der Hülle) ja nicht in der Nähe der Antenne abspielt.

[@beautifulsmall]

Thanks for highlighting this, it would be a great addition to any engineers workshop. Any chance of looking into 4G comms, I cant get signal on sim800 in the uk so moved to a SIM7600, would be great to see a review of 4G modules for sms and small data transfer.

[@AndreasSpiess]

I never worked with 4G so far. The modules are still quite expensive... Does the SIM7600 work?

[@electroGoal]

Can we use tl431 as a voltage supervisor

[@andymouse]

Well it is a Reference if that's what you mean.

[@AndreasSpiess]

I fear you need to add more parts. But I never thought about it

[@zandanshah]

Can you make a few educational clips for LibreVNA

[@AndreasSpiess]

I do not own such a device. Pluis it should not be very different in principle.

[@charlieoscar09]

Excellent video thankyou

[@AndreasSpiess]

Glad you enjoyed it

[@jonathanokocha4614]

what is the output power? is it same for the frequency range

[@AndreasSpiess]

A few mW at the same frequency range

[@haimik0]

Could I use this procedure to test active GPS antennas that require 3.3-5V power? How do I inject the power to test?

[@AndreasSpiess]

No.

[@tekanova7480]

Am I correct in thinking a nanoVNA is used for TX optimization only?

[@AndreasSpiess]

A proper antenna match is more important for a transmitter because it can blow up if not. But it helps also for receiving performance.

[@LionRoars918]

I have a 1090 MHz ground plane antenna with type N chassis mount. How do I measure the VSWR and impedance ? I have to use an adapter to connect it to the nanovna but how can I find out the required delay ?

[@AndreasSpiess]

You have to use an adapter and live with the small error if you do not have an N-type calibration set.

[@waltsteinchen]

Hi Andreas, again very good video!! .. In germany (probably also in switzerland) we fear a energy blackout in winter ... just for *that* situation: - I'm looking for a independant communication method to one person for a distance of ~50km .. (Textmesage like SMS f.e. would be ok .. anything more convenient of course also .. ) any way to solve that problem ? .. Lora ? CB-Funk with high power ? (I would ignore missing licences for that purpose) .. just to be able to do some very minimalistic communication on that distance ... any ideas ?

[@AndreasSpiess]

Without a line of sight, the only possibility (without relay or satellite) is to use HAMradio on the 80 or 40 meters band because these frequencies are reflected by the ionosphere (google NVIS)

[@lottery248]

do we have antennas receiving digital signals?

[@AndreasSpiess]

Yes, of course. Antennas do not care about analog or digital modulation.

[@EdoDijkgraaf]

Dear herr Spiess, Can a VNA measure the impedance of the headphones out on an amplifier? After all the audio signal is not constant. If one can measure the impedance of a "headphones out", I know what to ask for my birthday in june. Cheers!

[@AndreasSpiess]

VNAs are for high frequencies. They do not work with audio.

[@EdoDijkgraaf]

@@AndreasSpiess thank you. The variable frequency triggered my wish to measure audio related impedances.

[@AndreasSpiess]

@@EdoDijkgraaf Maybe you watch my video #413?

[@vke6077]

Great video, thanks! :-)

[@AndreasSpiess]

Glad you liked it!

[@SuperDTMF]

Thanks for the info

[@AndreasSpiess]

You are welcome!

[@ChannelofRichPierik]

Excellent!

[@AndreasSpiess]

Many thanks!