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Hi Everyone, I'm new to the VNA and trying to measure both inductance and capacitance but getting stupid results. Is there someone who has this version of the VNA could walk me through the setup and menu to do this please. I have checked and checked the various You Tube videos but I am not getting the results I should. I should also mention I am 80 years old. Trying to complete my QMX low pass filters. Failing to get any answers is there someone who would care to correspond by email with me. Very frustrated. Thank you for looking.

Though I have been using NanoVNA for a few weeks now, I was not aware that
it can be used for measuring inductance and capacitance. Now I will also
join your search!
Currently I use my LCR meter to measure inductance and capacitance.

73
Jon, VU2JO

On Sat, Apr 19, 2025 at 11:56?AM Phil Brown via groups.io <zapel406=
[email protected]> wrote:

Hi Everyone, I'm new to the VNA and trying to measure both inductance and
capacitance but getting stupid results. Is there someone who has this
version of the VNA could walk me through the setup and menu to do this
please. I have checked and checked the various You Tube videos but I am not
getting the results I should. I should also mention I am 80 years old.
Trying to complete my QMX low pass filters. Failing to get any answers is
there someone who would care to correspond by email with me. Very
frustrated. Thank you for looking.

Phil, Are you using Nano VNASaver software on your computer to connect to the NanoVNA or are you trying to do it directly? First thing to remember is, Calibrate at the connection you are using to check your inductors or capacitors etc. So if you are using alligator clips to connect to your parts, you need to use a 50 ohm resistor at that spot. Lead lengths need to be as short as possible because the wire leads do affect your readings. There are several jigs you can make to check various components. Let me say I am not real experienced with using the NanoVNA but I have used mine to check inductors to read the uH value on my VNA H4 with some success. I have found using my L/C meter is much simpler. There may be someone out there that has more experience with this than I but I will watch this thread and try to help you if I can.
Dean - KC9REN

Dean,

Can you kindly explain the method you have used to measure inductance and
capacitance with NanoVNA?

73

Jon, VU2JO

On Sat, Apr 19, 2025 at 5:11?PM Dean - KC9REN via groups.io <deanberg2044=
[email protected]> wrote:

Phil, Are you using Nano VNASaver software on your computer to connect to
the NanoVNA or are you trying to do it directly? First thing to remember
is, Calibrate at the connection you are using to check your inductors or
capacitors etc. So if you are using alligator clips to connect to your
parts, you need to use a 50 ohm resistor at that spot. Lead lengths need to
be as short as possible because the wire leads do affect your readings.
There are several jigs you can make to check various components. Let me say
I am not real experienced with using the NanoVNA but I have used mine to
check inductors to read the uH value on my VNA H4 with some success. I have
found using my L/C meter is much simpler. There may be someone out there
that has more experience with this than I but I will watch this thread and
try to help you if I can.
Dean - KC9REN

On Sat, Apr 19, 2025 at 01:25 AM, Phil Brown wrote:

Hi Everyone, I'm new to the VNA and trying to measure both inductance and
capacitance but getting stupid results. Is there someone who has this

version

of the VNA could walk me through the setup and menu to do this please. I

have

checked and checked the various You Tube videos but I am not getting the
results I should. I should also mention I am 80 years old. Trying to

complete

my QMX low pass filters. Failing to get any answers is there someone who

would

care to correspond by email with me. Very frustrated. Thank you for

looking.

Use Smith Chart. If your marker is in the upper half, it's inductive. If below, it's capacitance.

Sent from AT&T Yahoo Mail on Android

On Sat, Apr 19, 2025 at 7:46 AM, Jon via groups.io<vu2jo0@...> wrote: Dean,

Can you kindly explain the method you have used to measure inductance and
capacitance with NanoVNA?

73

Jon, VU2JO

On Sat, Apr 19, 2025 at 5:11?PM Dean - KC9REN via groups.io <deanberg2044=
[email protected]> wrote:

Phil, Are you using Nano VNASaver software on your computer to connect to
the NanoVNA or are you trying to do it directly? First thing to remember
is, Calibrate at the connection you are using to check your inductors or
capacitors etc. So if you are using alligator clips to connect to your
parts, you need to use a 50 ohm resistor at that spot. Lead lengths need to
be as short as possible because the wire leads do affect your readings.
There are several jigs you can make to check various components. Let me say
I am not real experienced with using the NanoVNA but I have used mine to
check inductors to read the uH value on my VNA H4 with some success. I have
found using my L/C meter is much simpler. There may be someone out there
that has more experience with this than I but I will watch this thread and
try to help you if I can.
Dean - KC9REN

On Sat, Apr 19, 2025 at 01:25 AM, Phil Brown wrote:

Hi Everyone, I'm new to the VNA and trying to measure both inductance and
capacitance but getting stupid results. Is there someone who has this

version

of the VNA could walk me through the setup and menu to do this please. I

have

checked and checked the various You Tube videos but I am not getting the
results I should. I should also mention I am 80 years old. Trying to

complete

my QMX low pass filters. Failing to get any answers is there someone who

would

care to correspond by email with me. Very frustrated. Thank you for

looking.

I second this! After you learn to properly calibrate the VNA in your test environment, look up YouTube videos on the Smith Chart, there are many. The chart will map resistance, inductance, and capacitance at every frequency of your sweep range... It's the key to getting the most from the VNA

Phil,
Even if you know how to use the VNA, measuring the QMX lowpass filters is tricky. I have done it a few times and can help you, but it would have to wait until Monday since I currently have family activities celebrating Easter. So if you would like me to walk you through it, please send me a message here and we can connect.

Hi Dean and everyone who gave an answer firstly thank you. Yes I am using Nano Saver on my laptop, yes I am aware of how to calibrate and the importance of measuring at the plane, yes I have made jigs and am aware of stray inductance and capacitance. Greg Messenger's videos seem to me to be the best way of using the nano vna to determine values but I don't seem to be able to replicate his menu settings and that is why I asked is Ver 1.2.27 different from earlier versions. All the videos on this subject are excellent but no one takes you through the menu steps to achieve the results.

Hi Stan, I gratefully will accept your kind offer of help. Thank you and I am not in a hurry. zapel406@...

Once you have calibrated you setup at the measurement plane including any
fixtures, the following may help you (I've got the VNA in front of me as I
write so I'll go through the steps). To measure inductors and capacitors
you need only do the OSL cal. There is no need to do the isolation and
through cals. It is best in measuring capacitors and inductors (and other
passive components) to cal. over the frequency(ies) of interest. If your
frequency range is wide, do several cals bracketting your center frequency
of interest. I'll use the native VNA with no PC or Saver, just the
stand-alone VNA.

1) Tap the VNA screen and tap "DISPLAY".
2) Then tap "FORMAT".
3) Then tap "SMITH".
4) Then tap "BACK" twice.
5) Then tap "MARKER".
6) Tap "SELECT MARKER".
7) Select (tap) MARKER 1". I usually turn off all other markers at this
point.
8) Tap the screen to eliminate the right-hand "choice bar".
9) With your finger or styles, move the marker to the desired frequency.
10) Note the numerals in the upper left of the VNA display. The default
for this expression is impedance in R ± jX. In my case, I'm using a 130 pF
dip mica and sweeping from 7.00 to 7.30 MHz. Tthe upper left reads for
this case reads "CH0 1.0FS 0.924Ω 128pF" The 0.924Ω represents the
resistive component of my dip mica while the 128pF represents the actual
value of my dip mica at the frequency at which the cursor is set. That's
what you are after.

Again, the area above the central horizontal line on the Smith Chart is
inductive reactance. The area below the central horizontal line on the
Smith Chart is capacitive reactance. ONLY the central horizontal line
represents pure resistance with no reactive component.

The procedure presented in the Greg Messenger's video for measuring
capacitors and inductors is also sound. Personally, I prefer the Smith
Chart method. However, his cautions are valid for either method.

Hope this helps?

Dave - W?LEV



1)

On Sat, Apr 19, 2025 at 7:31?PM Phil Brown via groups.io <zapel406=
[email protected]> wrote:

Hi Dean and everyone who gave an answer firstly thank you. Yes I am using
Nano Saver on my laptop, yes I am aware of how to calibrate and the
importance of measuring at the plane, yes I have made jigs and am aware of
stray inductance and capacitance. Greg Messenger's videos seem to me to be
the best way of using the nano vna to determine values but I don't seem to
be able to replicate his menu settings and that is why I asked is Ver
1.2.27 different from earlier versions. All the videos on this subject are
excellent but no one takes you through the menu steps to achieve the
results.

--

*Dave - W?LEV*


--
Dave - W?LEV

How do you measure a coax with my nanovna

Phil and John,

The NanoVNA is an excellent tool for measuring the inductance and capacitance of components. The S11 shunt method using CH0 (port 1) works well for most measurements. In order to get accurate measurements you need to use the following:

Proper test jig
----------------
- This has been discussed many times in this group and what you use depends on the type of components you want to measure and the accuracy you require. There are jig designs with photos in past group posts for SMD, leaded components and larger coils. The higher in frequency you want to measure the more critical the jig. For HF banana clips on the end of coax will give decent results if you calibrate using a non-inductive 50 ohm resistor.

Calibration
------------
Calibration must be done on the test jig itself at the point where you are going to measure the component. You will need to do a Short-Open-Load (SOL). Set the Stimulus frequencies for the appropriate range and remember to do a Reset before starting the calibration procedure. Verify once it is done by measuring the short, open and load and observing on the Smith Chart trace. The Short should have a dot at the far left on the horizontal axis, the 50 ohm load a dot in the middle and the open on the far right on the horizontal axis.

Measurement
---------------
You can observe L and C on the Smith Chart by going into the trace menu and selecting R+L/C and moving the marker along using the jog wheel. On later versions of DiSlord firmware you can set any S11 trace to Serial C or Serial L to for a graph. I prefer to use NanoVNA app on my PC but others like NanoVNA Saver.

Things to be aware of
------------------------
In the real world there are no ideal inductors or capacitors. A physical inductor will have resistance and stray capacitance and a capacitor will have lead inductance, series and parallel resistance. The NanoVNA and the PC programs do a simple calculation of L and C based on the reactance measured. The calculation of L = Xl/(2*pi*freq) and C = 2*pi*C*freq are not the true values and are referred to in the technical literature as apparent inductance or capacitance.

When measuring capacitors keep the lead lengths short or lead inductance will affect your measurements. Keep inductors away from conductive or magnetic surfaces.

When measuring inductors that use a ferrite core one needs to be aware that the inductance will change considerably with frequency. This is because the permeability of the core material changes with frequency and it is different for each "mix". A decrease in inductance is what occurs but stray capacitance will also have an opposite effect on the "apparent" inductance that is measured.

When measuring capacitors it may not be possible to accurately measure them below or above some frequency range using the S11 shunt method because the reactance may be too high or too low. For example a 1 uF ceramic capacitor will have less than 2 ohm of reactance at 100 kHz.

Experiment
-------------
Users should verify that their jig, calibration and frequency range are suitable by measuring some known components. Air wound inductors that are not tightly wound (low self capacitance) are good for initial tests. 10 to 100 pF caps also yield good results across HF frequencies.

Dave W0LEV, Thank you I have emailed you via your ARRL email address.