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This is what I get using an inductor (7 turns of RG58A through a toroid) and the component is connected to CH0 and calibrated: [image: afbeelding.png] You see the S11 |Z| graph is a straight line

Dave - Thanks once again for all the information. I'll test the modification using the 1/8 wavelength frequency in SimSmith and see how it compares. That change also allows the method posted by John

Did a quick search for RSGB sites as described but didn't have any luck. Could you provide a link or more info to help find them? TNX

Here are some S11 measurements I did "calibrating out" a 10 dB and a 20 db attenuator. Measurement errors get worse as you increase the attenuation but 6 dB won't be bad at all.

The last link on measuring Inductors had an error. Here is the corrected link.... /g/nanovna-users/message/20848 Roger

Joe, When measuring the inductance of a coil with a NanoVNA one needs to keep a few things in mind. The inductor will also have resistance and self capacitance. The self capacitance will affect the

How does the output load become part of the S11 measurement? I agree you need it to keep the amp happy, but when you make your?amplitude and phase measurements on the antenna tuner, the load

No....n o ....... N O..... I was dealing and referring to the INPUT which is what you requested! Yes, then read the combination looking back into the 50-ohm load and matching network which you have

As noted, the OP was looking at inputs, but someone else suggested a way to measure outputs. My comment was on that. Why would you want to feed an RF source to an output? Because you wanted to measure

"Then use the Nano to read the impedance of the tuner/dummy load?" This configuration?would be on the output of an amp, not the input. Measurement?of S22 and very often S12 can be very helpful as

Owen's posts can also be accessed on the RSGB sites. I subscribe to both the "antennas" and the "antennas research" sites from RSGB. Owen's posts are excellent and always technically and engineering

I was addressing the INPUT as the requester! Why would I feed an RF source to the output??????????? Dave - W?LEV

Some of you may be familiar with the blog of an Australia ham Owen Duffy. https://owenduffy.net/blog/ He posts on a wide range of topics and is technically quite knowledgeable. He "lurks" on this

That's more about measuring the amplifier's output impedance, I think the OP is looking for amplifier input impedance. Here's what's great about the NanoVNA - There's going to be people who figure out

Hi David, but the capacitance of the internal windings of a chip inductor are usually unknown.Of course after you have measured the SRF, you can then calculate it.Kent(I have fought this problem for

There is an excellent WIKI on this site. There is also a beginners guide to using the NANOVNAs. There are even a few good YouTube presentation available in the archives of this site. Dave - W?LEV

If you know the capacitor value, calculating the inductance from the resonance formula is trivial for any calculator. Just like the Grid Dipper! 2 f = 25330 / (L x C) f in MHz L in ?H C in pF This is

On very handy reading when making a wide frequency sweep of an inductor,is that you easily see the jump where the inductor is self resonance. You really don't want to use an inductor above it's self

d.u.t. is old cable or, perhaps, it's cable with an unknown history. Looking at it with a megger first might be considered. +++++

Is the tuner between the source and the amp, or between the amp and the load? But it's telling you more about what impedance the amp likes, not what it really is. Kent WA5VJB