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On Fri, Nov 15, 2019 at 11:00 PM, QRP RX wrote: " You can use complex pieces of cables with different impedance for testing it. For example: 1 meter 50 ohm + 1 meter 75 ohm + 1 meter 50 ohm + 25 ohm

On Fri, Nov 15, 2019 at 09:34 PM, Gabriel Tenma White wrote: " … It's the absolute accuracy and confidence in the measurements that you care about, and if you look at the smith chart that hugen

You can use complex pieces of cables with different impedance for testing it. For example: 1 meter 50 ohm + 1 meter 75 ohm + 1 meter 50 ohm + 25 ohm load.

The problem with this IFFT approach is that result looks like truth, but it is not. If you test it on different datasets, you will find incorrect results.

conjugate also cannot help. This is wrong approach. You're needs to interpolate S11, then use interpolation for integration step response. In such way it works ok. See my matlab script.

This approach is incorrect and leads to wrong results. It will give you even worse results with signed value. I wanted to add this into NanoVNASharp MOD, but it shows incorrect results and there is no

This is because SWR meters have high measurement error.

@Ron, K7UV: When you lay your hand on the SWR meter enclosure, do the meter needles move?

Hi Ron, Just to understand: You are disconnecting the cable from the back of the radio and connecting it to the vna? Is that correct? You are not using a different jumper or removing any of the

I'm using an external full-range tuner with a straight through (direct without using tuner function) reading to use the cross-needle SWR/PWR reading, so no, I'm not using the rig meter for SWR

Larry, Hugen posted a chart a few hours ago showing the results of a new PCB with some of the recent improvements installed (see attachment). S11 looks to be <= 40 dB to 1500 MHz and S21 dynamic range

On Fri, Nov 15, 2019 at 06:33 AM, Kurt Poulsen wrote: " I have done a lot of such measurements in the past and eliminated the inductance of the wire thru the core. > In your setup I think you get even

Thanks. I'm using a cross-needle meter without any tuner, so I'm matching the same antenna as measured with the Nano.

On Fri, Nov 15, 2019 at 01:01 PM, <erik@...> wrote: " Rune, > extend the s11 with the the complex conjugate of the s11 as input to the fft Then you can use only the real values as impulse

Never mind; I found them cheap on ebay.? Will order soon. Bob

Herman, Thank you very much for the information. Marco

Good afternoon! Depending on how everything in your rig is connected and/or grounded, switching from a rig that is connected to the powerline ground to the NanoVNA that is floating could change things

Rune, extend the s11 with the the complex conjugate of the s11 as input to the fft Then you can use only the real values as impulse response with the sign being correct. All imag values will be zero

Rune, I think that the TDR function is missing a trick in computing the observed impedance along a line. It looks like you are integrating the return impulses to get the impedance values, but ignoring

I did measure both with another vna. Ch1 is indeed worse but I found both to be closer to 50 ohm. Currently traveling so don't access to the exact numbers Next to the resistance difference ch1 has a