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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

New firmware from hugen: https://github.com/hugen79/NanoVNA-H/releases NanoVNA-H version compiled on November 15, 2019 Using the code of nanoVNA-Q of qrp73, the driving of si5351 and aic3204 is more

Hi Ron If it is the SWR indication build into your radio you are referring to, and your radio has an internal antenna tuner (or I would rather call it a impedance matching network), then the radio is

These figures for the impedance of CH0, CH1 will vary considerably with frequency. Jerry

What are you using to measure VSWR while transmitting. If you use a meter that simply changes scales with no re-normalization for any specific power, they are quite prone to read improperly when less

It's a shame they all appear to be 12V ;)

Thanks Larry. I'll try and find a "quality" one.

Thanks for the additional explanation, Herb. Sorry if I was too unclear. It would perhaps be possible for the software to have an 'auto' mode that started at a low frequency and increased it until the

Rune, I find myself quite often having to use an external graphics program to add descriptive text to the NanoVNA-Saver chart images I save (See attachment). Is it feasible to add a comment or title

On Fri, Nov 15, 2019 at 05:36 AM, Barry Jackson wrote: "If a particular frequency span setting, sweep mode etc. is needed for TDR measurements, should not the software set those modes temporarily when

This is my first post after lurking since October, so I'm quite new to the Nanovna. The Nanovna measurements of SWR are considerably lower than what I'm seeing when I transmit on-the-air. What does

Hello Rune, thank you for investing in the development of this measurement aplication very very close to the professional. I draw your attention to the TDR function or indeed the length marker is

Hello again, Thank you for the replies, and thank you Larry particularly. That was just what I needed. Well, I am not going to claim every single one of the 7000, because some are repetitive, and I

In post 1257: /g/nanovna-users/topic/32993803#1257 I calculated the output impedance of CH0 to be 51.53 ohms and the input impedance of CH1 to be 53.85 ohms. In the previous post of

That's probably a safe way to go, but the -H schematic is still showing the SD103AWS schottky while the STM32F072CBT6 datasheet has 4.0 max for the VBAT pin... not a lot of margin there.

Hi Herb 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 better result by doing a SOL calibration at the

The TDR range depends on the frequency step and hence the span. Use lower frequencies to measure long lengths and higher frequencies to measure short lengths. The software doesn't know in advance what