#315

This video shows, step-by-step, how to use the NanoVNA to measure a simple lowpass filter. The filter used in the video was originally featured in the Michigan Mighty Mite video (#228):
• #228: Radio Fun: Michi...
The video walks through trace selection and configuration, sweep setup, calibration and measurement. Please note that when running the calibration, the OPEN, SHORT and LOAD are connected to CH0 (not CH1). Please see my previous videos on VNA calibration, VNA basics, and other topics including Smith Charts to learn more. Notes from this video can be found here:
www.qsl.net/w2aew/youtube/nano...
The filter design software I used was from here:
www.tonnesoftware.com/elsie.html

[@mstjerning8919]

Great video as always! And remember folks, the Open, Short and Load calibration is on the CH0 cable and Isolation and Thru is on the CH1 cable as shown.

[@newq]

I just got one of these a few days ago and I feel like being a kid on Christmas morning every time I find out something else it can do. I don't think I've ever purchased a tool that has this much bang for your buck. Absolutely indispensable! Thank you for the excellent video. Explained everything very thoroughly.

[@TheDefpom]

With all of these VNA videos I might actually be able to figure out how to use my one once it arrives.

[@robertnagy2163]

Your channel is tremendously valuable to the Ham community. Well-done. Making VNA day #2 here a joy!

[@NexxuSix]

Thank you for the video, Alan. Your tutorials are showing me just how powerful this little VNA really is. I was happy with making a simple plot of one of my antennas. Thanks to your videos, now I can see how to configure the VNA for more complex analysis and measurements. 73!

[@silasmarner7586]

Great video as always. I've been using VNAs for over 30 years and you present the information very clearly.

[@FlyingShotsman]

Another fantastic video from my favorite RF guru. I'm learning a ton of practical, useful info from this series. Thanks, Alan!

[@gordonwedman3179]

Mine is on the way. Will be watching all these at least two more times.Many thanks

[@RadioWhisperer]

Love these VNA videos! Just got mine in and I'm looking forward to playing with it. Thanks for doing these

[@MrNetmask]

im waiting for mine :)

[@thunderbuilt77]

Nice! I'm really learning my way around these menu settings. Best instructor i've ever seen.I hope you never get tired of doing these videos or discover a new hobby like pottery or something lol.

[@gunnarisaksson8677]

Today I received the same VNA as you have from China. That makes your videos more informative than I expected. 😊😊😊

[@jj-js5sx]

That was an excellent video. You perfectly answered the questions that I asked after watching your previous video. I'm sharing a link to both videos with others. Thank you !

[@glennwoodward77]

Excellent video.... to be expected from you of course. Very cool product I’ve seen a few do videos on but your videos are the ones I value and trust. Thanks for such a professional and voluntary explanation of all these cool things us newbies and hobbyists love.

[@mirsalisawood4762]

I tried to take a note from your video, but your video is the best and concise note about the topic. Love your each and every video ❤️

[@Elephantine999]

Good video--clear, detailed without going into the weeds, and useful. Thanks!

[@lambdaprog]

It's worth creating a NanoVNA playlist. This content is gold.

[@ahmedsherif2182]

I am really inspired by you and your videos. I hope that one day i reach a fraction of your knowledge, God bless you and keep up the good work.

[@nopenadanowaynohow]

I have just began my first longer term "retirement" project. Hoping to build my own LDMOS Amp for HF. I have just started at the designing of my filters. This video is EXACTLY what I was needing !! Thank you again for taking so much of your time to contribute to the Ham and electronics hobbyist !

[@nopenadanowaynohow]

1988 24 yrs old new Ham License and a HW-101. 100' Roll of RG8 and a spool speaker wire from Radio Shack. Not even an swr meter. Had zero idea of how little a knew ! Had a blast, and still do learning and enjoying all these years later. And now that I am starting to have the time to dig in deeper, your videos have truly been a great help !

[@southernexposure123]

Thank you. I appreciate how you tell us they whys of the difference in what the application showed us what to expect and "why" the vna display wasn't an exact duplicate..

[@DeeegerD]

Getting interested in getting a VNA and the TinySA. When I became a HAM at 22 I wanted to create my own transciever one day. Almost 40 years later the tools are becoming available ;) Now I need to find that incentive again ;)

[@webejamn2]

First, your videos are exceptional and very informative. I am trying to measure the SWR and insertion loss of some coax switch's within the freq range of 1-460MHz. I fully calibrated my NVNA per your methods withing that freq range, and are using S11 for SWR and S21 LOGMAG for insertion loss. The problem I'm seeing is that when I measure between S11 and S21 (w/o DUT), the insertion loss is essentially 0.0db, whereas the SWR shows a slowly rising slope of 1.015@1MHz, 1.116@144MHz, 1.946@440MHz and 2.028@460MHz. If I disconnect S21 from S22, and attach a 50 Ohm load on S11, the SWR is essentially flat at

[@glenwoofit]

Excellent Video as always. I've got one of these but I don't understand it well enough so keep these videos coming. As I'm sure I will be using these as a reference when I'm using mine.

[@EwaldBurger]

Since i bought this vna several months ago i hoped Alan would do some video’s on it, and see how lucky i am/we are!

[@tomswisher5305]

Excellent video as always, Alan! I was waffling between the MiniVNA Tiny (at ~ $500) and the NanoVNA, but your videos tilted me to the NanoVNA.

[@w2aew]

at about 1/10th the cost, it's hard to justify the MiniVNA.

[@radioman4738]

I used this information to set up my NVNA to sweep an old HF Low Pass filter and it worked, only thing I did differently was to set the stop frequency much higher. Noticed that on 50 MHz there was a bit of loss so for those Hams that work this band you may want to look into this.

[@Steve-GM0HUU]

👍Just what I needed to start testing my hombrew HF filters with a NanoVNA. Thank you.

[@dtbishop]

Keep the VNA videos coming!

[@dman52566]

Great video. Really helped explain the setup and use of the nano vna.

[@DonDegidio]

Hi Alan, Nice video showing the NanoVNA features in use. I would say the filter meets the design requirements. Stay safe. 73 WB3BJU

[@hugovanderzee4944]

Exactly what I was looking for. Thanks.

[@stationvictormike3415]

Thanks for everything... I followed the instructions and got it down and works nice.

[@davidkierzkowski]

Great vid, these thing are cheap, popular, and not terrible! I like them

[@breadfan3415]

Amazing nanoVNA series!!

[@rogerp5816]

Could you do something similar to characterize unknown ferret cores to give you a good idea what mix they are?

[@BersekViking]

Fantastic video as always!

[@dxexplorer]

I have to say a big thank you for this video. Until now I just "had an idea" of how I should measure the filters. Not I actually know the proper way. I wasn't far... but now I will be spot on ))) 73 DE YO6DXE.

[@exus4mie]

Thanks for the video! For some reasons, it didn't work for me on my Windows 10 laptop, but no issue on another one with Windows 7 (same procedure as you described).

[@barrybarry6689]

I have a junkbix full of low pass filters. They are quite old since I have been a HAM since 1965. With your help an the Nano VNA H4 I can finally learn which filter truly works the best. I wonder if the “bandwidth” guy ever got his General and what toaster he is operating?

[@Tony770jr]

I ordered one. Very cool!

Great video, as always! Can you, please, cover measuring ferrite toroids using nanoVNA?

[@kd5ozy]

I just ordered one. I hope it will take the place of my bulky HP 8754 and normalizer

[@yo3cwt737]

Congratulations!!! Please thinking of doing a video with ferrite toroids BalUn/UnUn measurements on NanoVNA. Thank you!

[@RobB_VK6ES]

40 year lapsed amateur and just going through re-licencing ATM. How things have changed. Most up to date stuff is an IC720A, IC251A and IC207H but have a 7300 in the mail along with the nanovna. It is going to be essential given the area I have for antennas. VK6?? :)

[@W1ZY]

Very valuable tutorial.

[@seandoofer5720]

Excellent video. I didnt know about loading ch1 with the 50r load. Can this Vna be used to do this for powered filters?, I guess it might need an attenuator to avoid saturation.

[@Screamingtut]

which of the NanoVNA is best to get and from who?

[@john-allenduskglass3193]

this is awesome, i can almost understand this!

[@newmonengineering]

I have a need to translate any voltage above 5V to 5V or below with sensitivity on voltage change. I was thinking like a zener and a few resistior and potentiometer.. i need to measure a voltage drop that happens in 48 hours. Say I have 48V and in 48 hours its 30V is there a way I can measure that drop with an arduino Analog with any sensitivity to that small drop??? If you have any thoughts please i would love to hear how I could do that.

[@waynegram8907]

Can you make a video talking about different RF microstrip filters using your NanoVNA. You can make the microstrips filters using copper tape and explaining how microstrips work and the theory behind microstrips

[@Radiofreak1041]

These videos are fantastic! Can you some time make a video about phase measurements with this device?

[@w2aew]

On my list of future videos.

[@adrian_sp6def]

is it possible to measure harmonic contents of trx rf output using NanoVNA?

[@Testequip]

Thanks Alan. I think it's time for me to purchase a NanoVNA.

[@octavmandru9219]

One doubt with these products is accuracy. Well, I would call this one "proven by design". Excellent series, for regular humans who can't afford expensive equipment

[@Steve-GM0HUU]

Yes. I was concerned about accuracy. However, so long as you pay close attention to calibrating them, they seem to display acceptable results for hobby use.

[@omsingharjit]

i wanna see introduction video of saw on your channel ? any !?

[@Andy205ro]

Can this be used also to check antennas if are tuned for 5.8ghz? like PS200 does, but is only 2.7ghz

[@w2aew]

You would need one that covers that frequency range, such as the NanoVNA LITEVNA64 store2.rlham.com/shop/catalog/product_info.php?products_id=75669

[@fredrikragnarsson6889]

Great videos! I have learnt a lot from this channel. About the nanoVNA. Do you think it’s possible to measure s parameters of a BJT (at 144 MHz) and get fairly accurate results? I’m thinking of a home made board with sma connectors and circuits for biasing the transistor.

[@w2aew]

It might be a little dicey. One of the main problems is that you can't change the output amplitude of the NanoVNA (so it might not be the right amplitude for your tests), and the output is a squarewave (harmonic content might alter the device characteristics).

[@waynegram8907]

Why does various RF filters S21 will look the same using a 2 port S21 & S12 frequency response plot looks symmetrical. But the Smith charts complex impedance is different for S11 and S22, any reasons why the complex impedance are NOT symmetrical and the S11 and S22 are not at 50 ohms and have different complex impedances but the frequency response lots looks the Same symmetrical complex impedance?

[@typedef_]

Hey ! I need to transmit an analog HD video signal (AVI, TVI or CVI) over a line that is not coaxial and is not very long (max 50m or so). For this, I am using a differential line driver at one end and a differential receiver at the other to turn the signal back to single ended (these are some AD high speed op amps). What I found is that I need to have frequency dependent gain at the receiver (a low pass filter in the feedback loop) in order to receive the signal without distortions (ex. without losing color). Can I use this particular VNA to adjust that receiver gain so that I get as flat a response as possible over that line ?

[@w2aew]

You can, but you'll need to provide a balun at both ends to convert between unbalanced 50 ohm to the balanced line.

[@qrplife]

It would be interesting to compare the graph results from measuring this filter with the measurement done with the upgraded firmware from #320, provided you still have the same filter assembly available. Does the increase in number of points bring out the sharper dips in the S11 predicted by the design software?

[@w2aew]

I have. The dips in the S11 where a little deeper - but I don't recall how much, maybe another 10dB.

[@Testequip]

The German Hamfest live stream apparently indicated that the new Nanovna is being developed that peaks around 2 to 3GHz and that it might be worthwhile to wait until early next year when they become available. Has anyone heard anything regarding the above?

[@w2aew]

Yes, the S-A-A-2 (NanoVNA V2) goes to 3GHz. Available now, but only with small display and no enclosure. I would imagine that both of these issues will be addressed in the next few months...

[@najeebqureshi6409]

Can you make a video to measure resonant frequency of LC circuit. it will be agreat healp and useful for everyone.

[@KA6WKE]

I'm interested in using the NanoVNA to measure crystal filters. Could you do a video on this topic? Thanks and 73!

[@w2aew]

I'll add that to my list. In the meantime, the RF Guru Wes Hayward W7ZOI has a nice writeup on this: w7zoi.net/nanozoi.pdf

[@carldavis8228]

Keep it up.

[@mnh-jansson]

Great video! Any chance you could compare the NanoVNA to a professional grade VNA? And also maybe see what the real usable frequency range of the device is. I've heard that it is lower than advertised. Thanks again for the video!

[@w2aew]

I plan on doing this in future videos.

[@w2aew]

@@user-lp3cf5yn5b I did a bit of a comparison in this video: kzbin.info/www/bejne/fZrTdIl7qM6kjsU

[@kumismanis]

Thank you for understanding thru step calibration. But i think that this video more relevan give tittle "how to calibrate nano VNA"

[@kd5ozy]

going to try it on a 4 can set of sinclair BPBR 2m duplexers

[@w2aew]

Let me know how it comes out.

[@Roy_Tellason]

I figured early on that you pretty much favored BNC connectors, but have noticed lately that more stuff seems to be using SMA instead. (I rather prefer BNC myself.) I've also heard that SMA connectors have a fairly limited number of cycles when you can plug stuff into and out of them, but have not experienced this for myself just yet. I've considered getting some "savers" (an SMA male-to-femail adapter) to put on the Nano, but haven't gotten around to that yet. Your thoughts on this?

[@w2aew]

SMAs are pretty rugged. The 3.5mm and 2.92mm, which are all mechanically compatible with the SMA are a little less rugged. Connector savers are generally a good idea.

[@nouram5995]

Hello, There are different between librevna and nanovna?

[@w2aew]

I'm sure there are differences. I've never used a librevna, so I don't know what the differences are.

[@joejoe4games]

Love these NanoVNA videos... have you had a chance to look at the NanoVNA V2 yet? that think goes all the way to 3Ghz so some 2.4Ghz ISM stuff is a real possibility...

[@w2aew]

I haven’t gotten a look at the V2 yet.

[@bobkozlarekwa2sqq59]

I see you use the larger 4.3” display VNA. Where did you purchase it from? I have the smaller version.

[@w2aew]

I have the H4 - it is available from R&L Electronics.

[@Roy_Tellason]

@@w2aew That's where I got mine, along with some adapters for SO239, BNC.

[@carlosriccio7859]

Now is a new version OF nano VNa V2 that goes to 3Ghz without use harmonics, and still afordable, take a look

[@stevebailey1682]

Hi Alan...thanks for the good video. I have a question. I have the 2.8" version of the NanoVNA-H. I designed a Pi (low pass) filter (2 caps, 1 inductor) with a cutoff frequency of 150 Mhz. The idea is to reject everything from 400 Mhz on up. I am rejecting a 400 Mhz radiosonde transmission. When I put filter as DUT between S11 and S21 and measure S21...I see the 150 Mhz -3db corner...attention continues down as expected til around 280 Mhz (at -45db)...then as frequency increases from there...attention decreases. At 400 Mhz, attention is only -26db. I calibrated my Nano as instructed. Any idea what is going on? Thanks, Steve

[@w2aew]

Do you have any evidence that this is not how the filter is actually behaving? How are you connecting to the filter (clip leads or coaxial RF connectors)? Is the filter enclosed/shielded to prevent coupling from input to output?

[@stevebailey1682]

@@w2aew Hi Alan...my problem is inexperience. I just assumed I should be seeing a flat, stop-band upstream (up frequency) from a low-pass filter. Unfortunately, this is not what I am seeing. My filter is in a small metal box with BNC jackets on either end. Components are soldered directly to either the center posts or ground posts. Could my connecting cables be the problem...or are those potential artifacts calibrated out? Any further thoughts?

[@w2aew]

@@stevebailey1682 connecting cables could be leaking. As an experiment, remove the filter but leave the cables as the would be as if the filter were present. See how much attenuation you have at the higher frequencies. It is also likely that there is coupling from input to output inside your filter enclosure. You might try making a shield that separates the input from output inside the box, grounded to the box, with just small pass-thru holes for the connections

[@miketoreno4969]

Damn that is a good device.

[@rjrodrig]

What tool did you use to simulate the filter? ADS, Nuhertz, Genesys?

[@w2aew]

Elsie from Tonne Software.

[@bfx8185]

THX excellent

[@Halerno]

Great. ( really great) Tnx a lot. '73

[@jj-js5sx]

Trivia question. Unrelated to this video. Some experiences from my early childhood stick in my mind- not many, and not clearly, but some. One was a call-sign that a neighbor had. I've looked it up a couple of times, but can't find it listed. I would guess this is from circa mid to late '60s. I thought the call-sign was KKI3597 (kilo kilo India 3597 -- Maryland). Did call-signs change, or is my memory playing tricks on me? Thanks.

[@w2aew]

That was a call sign for Citizen’s Band Radio, back when that service required a license. It is not a ham radio call sign.

[@jj-js5sx]

@@w2aew ah- great. That makes sense. Thanks for the lead !

[@shrutisrivastava8977]

The display always shows S11 and S21. How could we measure S22? Also, Open, Short, and Load should be connected (while doing calibration) on both ports, and I don't see the option to change the port while calibrating the port 2. Please help.

[@w2aew]

The nanoVNA is a 2-port, 1-path VNA. This means that it has an RF source only on 1 port. Thus, it can't measure S12 or S22 at the same time as S11 and S21. The only way to measure the reverse parameters is to reverse the connections to the device under test.

[@shrutisrivastava8977]

@@w2aew Thanks. It makes sense. Are there some documents showing its detailed internal architecture?

[@w2aew]

@@shrutisrivastava8977 If you google "nanovna schematic", you will find a lot of references

[@shrutisrivastava8977]

@@w2aew thanks.

[@pratwurschtgulasch6662]

I have a (perhaps stupid) question, when the frequency is outside the pass band of the filter, I always thought the filter is essentially eating up the power but in your demonstration it looks like all the power is reflected back to the source. that can't be good or is my understanding wrong? perhaps since there is no 50 ohm resistor involved the power has to go somewhere... learning new stuff all the time :D

[@w2aew]

It depends on the filter design whether signals outside of the passband are reflected or absorbed.

[@pratwurschtgulasch6662]

@@w2aew well i learned something new thanks to your video :) it looks like all common filters reflect the signal back, i never knew that. for a low-pass or high-pass i think one has to make 2 filters side by side to split the signal like a cross-over and then direct one into a 50 ohm resistor. i'm going to do some research on this :)

[@electronic7979]

👍👍👍

[@wolfmonk9d]

I wonder what the IF bandwidth is, likely it has an order of 100 kHz or so. It's a fairly wide IF bandwidth but IMO reasonably narrow to get accurate measures of low pass and high pass filters. I have no idea what minimum band-pass filter bandwidth can be measured by NanoVNA, but will investigate it when my NanoVNA will arrive at me. :) I also want to measure its uncorrected parameters to figure out its precision.

[@w2aew]

I think it’s on the order of 10kHz

[@wolfmonk9d]

@@w2aew yes probably. I'll try to check specifications or even try to measure it when possible.

[@Manawyrm]

@@wolfmonk9d It uses a regular audio codec chip, that limits the IF bandwidth a bit...

[@w2aew]

I remember reading somewhere that it down converts to 5kHz, that what made me think the IF BW is

[@wolfmonk9d]

@@w2aew exactly. I always confuse NanoVNA with grown-up devices like Agilent or R&S which I'm dealing with at the office. Their usual default IFBW somewhat 10-100 kHz. But grown-up devices have a slightly different architecture. :)

[@TheArtofEngineering]

Thanks de VK2AOE....73

[@waynegram8907]

I'm confused what the complex impedance is a spiral circle, what is causing the complex impedance to be a spiral circle pattern? and how can you change/alter the complex impedance pattern? can you show how to do that in a youtube video because changing the inductance and capacitance doesn't change/alter the complex impedance pattern

[@w2aew]

Take a look at my impedance matching videos with the Smith chart to learn more about that.

[@waynegram8907]

I have watched your videos on the smith chart about the upper part of the smith chart is the inductances and the lower part below the mid line is the capacitance. I'm very confused about when you measured the antenna in your video adjusting the inductance dial knob and capacitance dial knob that it didn't change the complex impedance arch, curve, spiral circle. Any reasons why and what does alter/change the complex Impedance of the Antenna? or RF filter circuit?

[@nathankatz2529]

Wow, hard-core set-up ...

[@zvpunry1971]

Now I know how to deal with that touch screen. I'll attach a plectrum to a corner of the NanoVNA. ;-)

[@Testequip]

Don't tell me you a guitarist as well Alan

[@allenlutins]

According to his reply to a comment in the previous video, that pick came with his NanoVNA. My NanoVNA didn't come with a pick or stylus, but (like Alan's) it has the larger touch screen, and I don't have any trouble using my fingertips to select menu items (although you may want to use a stylus to avoid smearing the screen).

[@cijymathai1235]

Hi Alan, thanks a lot for solving our doubts on RF stuff. Regarding VNA calibration, I have a doubt. I wonder how to do the calibration if I have a circulator in the transmission (S21) setup as shown in the link below drive.google.com/file/d/1hw2uE5iOTcQSFHt902wwOkVx-izm9MTd/view?usp=sharing. Would you please clarify my doubt? Your help will be highly appreciated. Thanks in advance.

[@w2aew]

If you're interested in having the calibration compensate for the circulator (i.e. remove it's effects from the measurement), then the thru calibration should connect Port1 to the DUT port of the circulator, and the output to Port2 as shown.

[@cijymathai1235]

​@@w2aew Thanks for the immediate reply, Alan. I will try and let you know if the calibration turns out bad... Assume it has gone well otherwise... :)

[@ydonl]

The Joker: "Where does he get those wonderful toys?"

[@cameronturner7475]

I'm just a guy trying to pass my general, get on HF and do a little DXing. This is just eating too much bandwidth for me.

[@garywaddingham7179]

I never saw the video. I quit during the third long ad.

[@w2aew]

Sorry, I have no control over that. Most of the adds are "skippable" after the first 5 seconds or so - at least that's the case on a Windows PC / browser platform.

[@donepearce]

Why do radio amateurs use SWR? Return loss is a far better, more informative measurement.

[@w2aew]

Likely it has a lot to do with the availability and cost of the measurement gear. Traditionally, the least expensive tool that is available or used by amateurs is the SWR meter, either built-in to the radio or external.

[@webejamn2]

First, your videos are exceptional and very informative. I am trying to measure the SWR and insertion loss of some coax switch's within the freq range of 1-460MHz. I fully calibrated my NVNA per your methods withing that freq range, and are using S11 for SWR and S21 LOGMAG for insertion loss. The problem I'm seeing is that when I measure between S11 and S21 (w/o DUT), the insertion loss is essentially 0.0db, whereas the SWR shows a slowly rising slope of 1.015@1MHz, 1.116@144MHz, 1.946@440MHz and 2.028@460MHz. If I disconnect S21 from S22, and attach a 50 Ohm load on S11, the SWR is essentially flat at