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Several months ago, possibly last year even, there was some discussion here about the nanoVNA-H4 as having built onto the boards either a jack that would accept micro-SD cards or at least the circuit

Roger, My apologies for the late reply, delivering curry, toilet rolls and various biscuits around the country has kept me away from home. Thank you very much, will look into this as I am now off for

JMR, You have a NanoVNA-H. Correct? Which version of firmware are you using for best results? I will try to make a comparison since I have -H and -H4 NanoVNAs. Roger

I can try the latest firmware to see if things are improved but can you post up a link and a version number to try?

Hi Dislord, thanks for the reply. I don't know if this is useful but I did briefly try several versions of newer firmware (including yours) on my nanoVNA-H and I found the performance wasn't as good

Can you get last NanoVNA firmware and made measure vs small bandwidth setthing (30Hz ?) This should reduce noise

Here's the nanoVNA attempting the same test. This is a really nice (expensive!) PPI 1111 560pF cap in series with a 0.333R resistor and also just the PPI 560pF cap without any added resistance. The

OK thanks. I've not studied the nanoVNA beyond the input to the ADC so I don't know how it does things in firmware. To try and counter the research article that Roger linked to I dug out another PPI

On 3/23/21 7:48 PM, Roger Need via groups.io wrote: > On Tue, Mar 23, 2021 at 07:24 PM, jmr wrote: > >> I've not actually looked inside my nanovna but a quick glance at the online >> schematic shows a

On 3/23/21 7:24 PM, jmr via groups.io wrote: > On Wed, Mar 24, 2021 at 12:39 AM, Roger Need wrote: >> I did some research today on how the NanoVNA calculates the reflection >> coefficient, Gamma, from

On 3/23/21 5:39 PM, Roger Need via groups.io wrote: > On Tue, Mar 23, 2021 at 06:15 AM, Jim Lux wrote: > > >> You should really be looking at the I/Q uncertainty (R and X) rather >> than mag and

On Tue, Mar 23, 2021 at 07:24 PM, jmr wrote: > I've not actually looked inside my nanovna but a quick glance at the online > schematic shows a classic resistive bridge. When you connect a test circuit

I've not actually looked inside my nanovna but a quick glance at the online schematic shows a classic resistive bridge. When you connect a test circuit to the CH0 input the bridge in the nanoVNA

If anyone does read the paper linked to by Roger the test setup for s11 in that paper is shown in figure 4 and it is awful with bits of wobbly copper tape and a metal bar making up the short and the

An interesting paper "Measuring Capacitor Parameters Using Vector Network Analyzers" by Stepins, Asmanis, and Asmanis might be of interest to members of this group. The three common methods of

Jim,, I did some research today on how the NanoVNA calculates the reflection coefficient, Gamma, from the digitized bridge signals. There is very little information on this available and the firmware

Jeff I have been using the ancient bridges for years and still use them for the high Z's. Yes! All of these ancient bridges had to go thru an initial balance for each freq. Not to mention you needed

Sorry, I made a slight goof with the last plot as the trace for the poly 470pF cap was from the wrong S1p file. To make the traces overlay correctly I have to make sure that both VNAs have the same

To make things harder for the nanoVNA I pulled a couple of 220pF ceramic disk caps from an old Cobra 148GTL-DX CB radio that was probably made in 1981. I put them in parallel to make up 440pF. These

Isee, it is complex but can be accurate. But as I understand it you really have to relate the thermal losses to the real power loss, reactive power does not produce heath. Regards, Ignacio EB4APL