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

Рет қаралды 96,371

Жыл бұрын

Is this antenna good or bad, and for which frequency is it useful? A question I am often asked. Because a lousy antenna reduces the range of a device considerably. Or another question: Did the supplier cheat on this filter? At the end of this video, you will be able to answer these questions with confidence. And you know everything you always wanted to know about how to properly use a NanoVNA and the Smith Chart.
My HAMradio channel: / hb9blawireless
Links:
LiteVNA 4": s.click.aliexpress.com/e/_A6jaWD or amzn.to/3pR70Sg
4" Type N NanoVNA V2: s.click.aliexpress.com/e/_Dnl... or amzn.to/3AwbRNw
RF Demo Kit: s.click.aliexpress.com/e/_AnJR0X or amzn.to/3AsOILZ
nanoVNA Kit PCB: s.click.aliexpress.com/e/_98dlH7
Original nanoVNA: www.tindie.com/products/hcxqs...
Forum from the inventor of the nanoVNA (Lots of info, up-to-date): nanorfe.com/
VNA_QT Software: github.com/nanovna-v2/NanoVNA...
NanoVNA-Saver: github.com/NanoVNA-Saver/nano...
W2AEW Channel: / w2aew
The links above usually are affiliate links that support the channel (no additional cost for you).
Supporting Material and Blog Page: www.sensorsiot.org
Github: www.github.com/sensorsiot
My Patreon Page: / andreasspiess
Discord: / discord
If you want to support the channel, please use the links below to start your shopping. No additional charges for you, but I get a commission on your purchases to buy new stuff for the channel
My Amazon.com shop: www.amazon.com/shop/andreassp...
For Banggood bit.ly/2jAQEf4
For AliExpress: bit.ly/2B0yTLL
For Amazon.de: amzn.to/2r0ZCYI
For Amazon UK: amzn.to/2mxBaJf
For ebay.com: ebay.to/2DuYXBp
profile.php?...
/ spiessa
www.instructables.com/member/...
Please do not try to email me. This communication channel is reserved for my primary job
As an Amazon Associate, I earn from qualifying purchases
#no#midroll#ads

Пікірлер: 266

@mortalwombat5811 2 ай бұрын

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 2 ай бұрын

Glad you enjoyed it!

@nflgun Жыл бұрын

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 Жыл бұрын

Thank you for your kind words!

@davideisenberger6197 2 ай бұрын

“EXCELLENT presentation!!” Thank you!!

@davideisenberger6197 2 ай бұрын

I agree with you!

@MyTube4Utoo Ай бұрын

*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 Ай бұрын

Glad it helped!

@damny0utoobe 3 ай бұрын

Its becoming an antenna classic on KZfaq

@AndreasSpiess 2 ай бұрын

That was my plan ;-)

@fillphrench Жыл бұрын

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

@AndreasSpiess Жыл бұрын

You are welcome!

@PilotJimmyJ Жыл бұрын

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 Жыл бұрын

I am sure you will enjoy the device!

@asperheim Жыл бұрын

Possibly one of your best videos. Truly excellent.

@AndreasSpiess Жыл бұрын

Glad you think so!

@asperheim Жыл бұрын

@@AndreasSpiess the pleasure is all mine.

@veedonfleece3694 Жыл бұрын

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 Жыл бұрын

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 Жыл бұрын

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

@ishwarm5842 Жыл бұрын

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 Жыл бұрын

Happy to hear that!

@aronhighgrove4100 Жыл бұрын

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 Жыл бұрын

Thank you for your kind words!

@TowerGMLtdInfo 4 ай бұрын

Thank you the detailed explanation of my NanoVNA.

@AndreasSpiess 4 ай бұрын

You are welcome!

@nigelman9506 Жыл бұрын

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 Жыл бұрын

Glad it helped! Indeed, these are valuable devices.

@_adamalfath Жыл бұрын

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 Жыл бұрын

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

@bayareapianist Жыл бұрын

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

@AndreasSpiess Жыл бұрын

@@bayareapianist HB9BLA wireless

@skydivingcomrade1648 Жыл бұрын

As always a pleasure to watch and learn from your videos

@AndreasSpiess Жыл бұрын

Thank you!

@doco6186 Жыл бұрын

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 Жыл бұрын

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.

@ethzero 3 ай бұрын

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 3 ай бұрын

Glad I could help! And enjoy Meshtastic.

@k6aaq64 3 ай бұрын

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

@AndreasSpiess 3 ай бұрын

My pleasure!

@AbuSous2000PR Жыл бұрын

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

@AndreasSpiess Жыл бұрын

Glad you liked it!

@karlmatthias2698 Жыл бұрын

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

@AndreasSpiess Жыл бұрын

My pleasure!

@johnkweber1 Жыл бұрын

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

@AndreasSpiess Жыл бұрын

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

@Jyaastn Жыл бұрын

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 Жыл бұрын

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 ;-)

@Jyaastn Жыл бұрын

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

@josediaz2643 4 ай бұрын

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

@AndreasSpiess 4 ай бұрын

You are welcome!

@mortenlund1418 Ай бұрын

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

@AndreasSpiess Ай бұрын

Glad it was helpful!

@BerndFelsche Жыл бұрын

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

@AndreasSpiess Жыл бұрын

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 ;-)

@science4allworld587 Жыл бұрын

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

@AndreasSpiess Жыл бұрын

Glad it was helpful!

@jakedillingham Жыл бұрын

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

@AndreasSpiess Жыл бұрын

Glad it was helpful!

@spacecase0 Жыл бұрын

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 Жыл бұрын

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...

@jps99 Жыл бұрын

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

@AndreasSpiess Жыл бұрын

Glad it was helpful!

@gnormhurst 4 ай бұрын

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 4 ай бұрын

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

@GiNodrog 4 ай бұрын

Brilliant and very informative video, thank you.

@AndreasSpiess 4 ай бұрын

Glad it was helpful!

@newYorkStories 3 ай бұрын

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

@AndreasSpiess 3 ай бұрын

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

@ParadoxTransistor 7 ай бұрын

Excellent and useful information, very good explanation as well!

@AndreasSpiess 7 ай бұрын

Thank you!

@darylmorse 2 ай бұрын

That was very interesting. Thank you for sharing!

@AndreasSpiess 2 ай бұрын

My pleasure!

@TheChalansillo 2 ай бұрын

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

@AndreasSpiess 2 ай бұрын

Indeed, the devil lies in the details ;-)

@davidm1635 2 ай бұрын

appreciate your distribution of knowledge!

@AndreasSpiess 2 ай бұрын

:-)

@user-gf2mr8uf8d 4 ай бұрын

Thank you. Very interesting and informative.

@AndreasSpiess 4 ай бұрын

Glad you enjoyed it!

@adjudant-chefwillsdorff6037 Жыл бұрын

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 Жыл бұрын

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

@user-dj6mf9ko3d 2 ай бұрын

Fantastic video! Thank you very much.

@AndreasSpiess 2 ай бұрын

Glad you liked it!

@slonbeskonechen8310 Ай бұрын

Great tutorial! Thank you!

@AndreasSpiess Ай бұрын

My pleasure!

@nmidu Жыл бұрын

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

@AndreasSpiess Жыл бұрын

Thanks for watching!

@R73CH Жыл бұрын

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 Жыл бұрын

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?

@chuxxsss Жыл бұрын

Afternoon Andreas, and yes found gold today.

@AndreasSpiess Жыл бұрын

Cool. Congratulations!

@RoguePlank 6 ай бұрын

Omg the tiny hand, bless

@AndreasSpiess 6 ай бұрын

:-))

@Anthony_Matabaro_3D_360 Жыл бұрын

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

@AndreasSpiess Жыл бұрын

Thank you. Now it should work...

@SeAfasia Жыл бұрын

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

@AndreasSpiess Жыл бұрын

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

@SeAfasia Жыл бұрын

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

@AndreasSpiess Жыл бұрын

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

@nileshkumar4606 Жыл бұрын

very good information thanks.

@AndreasSpiess Жыл бұрын

You are welcome!

@charlieoscar09 Жыл бұрын

Excellent video thankyou

@AndreasSpiess Жыл бұрын

Glad you enjoyed it

@shortwaverPL Жыл бұрын

Thanks a lot for this!

@AndreasSpiess Жыл бұрын

You're welcome!

@victorb22622 Жыл бұрын

Very very informative video

@AndreasSpiess Жыл бұрын

I am glad you think so!

@hugopristauz3620 Жыл бұрын

excellent crash course 🙂

@AndreasSpiess Жыл бұрын

Thank you!

@SuperDTMF Жыл бұрын

Thanks for the info

@AndreasSpiess Жыл бұрын

You are welcome!

@TRETT1956 Жыл бұрын

Sehr gut gemacht - Dankeschön Werner

@AndreasSpiess Жыл бұрын

Gern geschehen!

@rilosvideos877 5 ай бұрын

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 5 ай бұрын

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

@rilosvideos877 5 ай бұрын

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

@vke6077 Ай бұрын

Great video, thanks! :-)

@AndreasSpiess Ай бұрын

Glad you liked it!

@DimitriVolkmannSY 10 ай бұрын

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 10 ай бұрын

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.

@beautifulsmall Жыл бұрын

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 Жыл бұрын

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

@catalinalb1722 9 ай бұрын

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 9 ай бұрын

Yes.

@EricWAtchesVideos 11 ай бұрын

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 11 ай бұрын

Good to know! Thanks.

@krist0sh 8 ай бұрын

Thank you!

@AndreasSpiess 7 ай бұрын

You're welcome!

@ChannelofRichPierik Жыл бұрын

Excellent!

@AndreasSpiess Жыл бұрын

Many thanks!

@alexanderwagner9524 Жыл бұрын

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 Жыл бұрын

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.

@ceeb830 10 ай бұрын

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 9 ай бұрын

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

@Maksim-Laika Ай бұрын

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 Ай бұрын

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

@tester30466 6 ай бұрын

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 6 ай бұрын

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?

@ernestofigueroa9278 10 ай бұрын

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 10 ай бұрын

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.

@uberschall_4714 Жыл бұрын

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 Жыл бұрын

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

@uberschall_4714 Жыл бұрын

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

@LionRoars918 6 ай бұрын

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 6 ай бұрын

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

@zenzeni77 Жыл бұрын

It all went right above my head 😅😂

@AndreasSpiess Жыл бұрын

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

@robertkras5162 Жыл бұрын

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

@AndreasSpiess Жыл бұрын

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

@shanieboi86 Жыл бұрын

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 Жыл бұрын

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

@Pootycat8359 Жыл бұрын

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 Жыл бұрын

I agree.

@stevexiao1488 4 ай бұрын

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 4 ай бұрын

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.

@adbas6201 Жыл бұрын

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

@AndreasSpiess Жыл бұрын

I never tried.

@mikez484 2 ай бұрын

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 2 ай бұрын

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

@N00kproof Жыл бұрын

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 Жыл бұрын

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.

@W4TRI Жыл бұрын

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

@AndreasSpiess Жыл бұрын

Maybe...

@waltsteinchen Жыл бұрын

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 Жыл бұрын

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)

@edieharo4186 Жыл бұрын

Thanks!

@AndreasSpiess Жыл бұрын

Thank you for your support!

@PhG1961 Жыл бұрын

Really awesome. I often think about this video, i.m.h.o one of the best.

@AndreasSpiess Жыл бұрын

This is why I thought it has owned a chance for a revival ;-)

@haimik0 10 ай бұрын

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 10 ай бұрын

No.

@Pootycat8359 Жыл бұрын

A note on what I just posted: "VSWR" is pronounced "viz-wahr."

@AndreasSpiess 11 ай бұрын

I do not like this pronunciation because is sounds like "pissoir" ;-)

@aronhighgrove4100 Жыл бұрын

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

@AndreasSpiess Жыл бұрын

You are right!

@ChaplainDaveSparks 21 күн бұрын

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 14 күн бұрын

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).

@w8lvradio Жыл бұрын

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 Жыл бұрын

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.

@stargazer7644 8 ай бұрын

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 8 ай бұрын

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

@stargazer7644 8 ай бұрын

@@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 8 ай бұрын

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

@stargazer7644 8 ай бұрын

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

@flat-earther 8 ай бұрын

@@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.

@KillerSpud Жыл бұрын

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

@AndreasSpiess Жыл бұрын

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.

@tonyvzt3938 Жыл бұрын

Thanks

@AndreasSpiess Жыл бұрын

You are welcome!

@bryanrude8072 Жыл бұрын

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 Жыл бұрын

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

@Vggcs Жыл бұрын

@Andreas Spiess I need help mr Andreas 🙂 What is best way to control level of must in high tanks while filling it instead climb a ladder every half hour to check level? Any type of sensor to recommend me or something else that can help? Thank you Sorry for not so good english 👋🏻

@AndreasSpiess Жыл бұрын

I made two videos about this topic.