nanoVNA - Measuring Inductors and Capacitors (Vers. 3)

This method is not for higher frequency characterization of components. It simply allows a person to determine the basic low frequency values of inductors and capacitors to identify or confirm their values.

2:30 - calibrating the nanoVNA
3:23 - looking at an inductor
9:20 - looking at a capacitor

Aug 2021 - For clarity, I would like to address the fact that measuring the reactive device under test at 50 ohms is not done because it “matches” the source impedance in the traditional sense that this concept would be understood by amateur radio operators with regards to maximum power transfer theory. This is not the intent at all. Rather, as has been stated in the video and supporting documentation, 50 ohms is used primarily because it lies within the shunt method’s best accuracy region. Secondary reasons include: it’s at 90 degrees on the smith chart (the top or bottom depending on what you’re measuring), is easy to remember, makes measurements consistent, keeps people away from going too low in frequency, avoids the self resonant frequency of the device and test fixture.

[rfjgfude]

Best tutorial on measuring inductors and capacitors on a Nano VNA I've seen yet. Thank you.

[dondonaldson]

Hi Gregg, this RF Engineer didn't "cringe". When I looked at your test setup I thought "those leads are going to be resonant" because there is parallel capacitance induced. This is shown exactly in the sweep trace of the vector network analyser. 15uH is small, as are the few pico Farads across the alligator clips at the reference plane. If the resonant frequency is 10 MHz, one can easily calculate the amount of intra-lead capacitance. Inductive reactance is 2 pi f L and capacitive reactance is 1/2 pi f C. At resonance the magnitude of XL is equal to the magnitude of XC and they are 180 degrees out of phase. Your method is excellent, by the way and shows exactly why there is focus in the amateur radio exam regarding series and parallel tank circuits!!! Well done. Don, VE3NAP

[intotheblue]

Showing how you do this has really enabled me to see how I can use a VNA to tackle my projects thank you very much.

[homeralbufera]

Thanks for sharing! I have just bought a NanoVNA from China that will be arriving next week. It's helpful to me and other hams around the world to determine the value of inductor which could not be read by available multimeter. I will use this knowledge to design a telescopic antenna 1.3 meter long to resonate at 10 meter band using a tank circuit.

[Steve-GMHUU]

Thanks for posting - very useful. No doubt about it, the NanoVNA is an amazing tool for the radio ham or any RF hobbyist.

[lmantuano]

GM, I keep on coming back to your videos for the value of the information and the clear and calm way you deliver it.. you are good!
73 de vk3ola

[gerd]

I‘m new to NanoVNA and your video helped me a lot to understand the way things work. Thanks a lot!

[KRFT]

This is really helpful! Thanks so much for passing along the method - and the rationale behind it! It will be very helpful in my component testing.

[richardphillips]

Thank you. I've learned a lot from this video. This video serves as an inspiration to learn more about rf transmission.

[barrykery]

I always wondered why my readings were not constant so I never used my VNA to check those values. I do have an LCR meter but now I know how to use my VNA. Great video. Thanks for posting.
Barry, KU3X

[acestudioscouk-Ace-GACE]

Clearly explained and understood by this beginner. Thank you.

[bobgarrett]

Thanks for posting. Was struggling with measuring an inductor and this should work!

[leomartihart]

jaja que los ingenieros no miren el video!!!
Importante la calibracion.
gracias por tu trabajo.

[cbnation]

Regarding the "strange" measurements you have at the beginning of the video with the inductor, they are probably right and the most useful thing you measured. You found the self-resonance point of the component. Beyond that, the inductor behaves as a capacitor and is not useful anymore for those frequencies. 73 de ON4CKM

[richardchambers]

Great information! You andwered my questions in the first 3 minuits. Thx. W6rch

[ozioldman]

Thank you for the video. Was struggling with the NanoVNA. This demistified the magic somewhat

[nathanwaller]

Thanks for the concise video. It would be great if you could show how you get the shunt settings on the vna for the totally green like myself. If you can explain the setup process, I'd be very grateful.

[johnwest]

I don't know if it's 'right', (or if it matters, ) but I was taught on the color code for resistors and inductors that the 'multiplier' band started with black being 'zero', and the band itself indicating how many zeros to add to the number obtained by the previous bands. In practice, I don't think it matters. It's just a matter of point of view, but it might cause some confusion among those who have learned the color code described the other way.

[gustavowkaiser]

Very nice approach. You got the point. Too low or too high impedances related to 50 ohm, makes difficult for the instrument to calculate the values which will be displayed. I use to preset 7 calibrated frequency bands, for instance, the first ranging from 50KHz to 5MHz, the second from 5MHz to 50MHz and so on, up to 3GHz, so the full range of the instrument is covered. As there are 7 memory slots to save the calibrated bands, one can easily switch to the band of interest, by means "recall" function.

[tegra]

Beautiful explanation of not only “how to” but also the right amount of context! I feel just a little bit smarter! (VA7TQB)