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-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Bob Shaw
Sent: Sunday, August 11, 2019 1:31 AM
To: [email protected]
Subject: [nanovna-users] Accuracy of the nanoVNA units

Has anyone measured some high resistive and inductive/capacitative loads and compared the resultant reported impedance with the results of the same loads on a known more accurate VNA? This would be interesting and relatively easily done if you have access to a professional grade VNA (which I don't).

-------- Original message --------From: alan victor <avictor73@...> Date: 11/08/2019 12:19 (GMT+01:00) To: [email protected] Subject: Re: [nanovna-users] New file uploaded to [email protected] I suspect the issue is the one dll (dynamic library link) present. The windows compiler does give you the option at compilation to select 32/64 or BOTH. Get the original code and re compile for 32.________________________________From: [email protected] <[email protected]> on behalf of tuckvk3cca <tuckvk3cca@...>Sent: Sunday, August 11, 2019 7:20 AMTo: [email protected] <[email protected]>Subject: Re: [nanovna-users] New file uploaded to nanovna-users@...? Alan. I have home brewed several vnas by now, everyone is a lesson. And we get a better instrument each time. On another note, I couldn't? get my nano to run on an old pc 32 bits with Win 7. The supplied driver for it is 64bit for some reason and failed. Where can I find a 32 bit driver?Sent from my Samsung Galaxy smartphone.-------- Original message --------From: alan victor <avictor73@...> Date: 11/08/2019? 01:34? (GMT+01:00) To: [email protected] Subject: Re: [nanovna-users] New file uploaded to [email protected] Hey guys, take it easy.... I was simply putting forth a very basic question. No more complicated than asking a ham... amateur radio op.... What's the sensitivity of that voltmeter your using to measure that voltage. Gee... it's just a fundamental question. Nothing more, nothing less. I said nothing about comparing it to anything.

-------- Original message --------From: alan victor <avictor73@...> Date: 11/08/2019 01:34 (GMT+01:00) To: [email protected] Subject: Re: [nanovna-users] New file uploaded to [email protected] Hey guys, take it easy.... I was simply putting forth a very basic question. No more complicated than asking a ham... amateur radio op.... What's the sensitivity of that voltmeter your using to measure that voltage. Gee... it's just a fundamental question. Nothing more, nothing less. I said nothing about comparing it to anything.

-------- Original message --------From: Warren Allgyer <allgyer@...> Date: 10/08/2019 23:57 (GMT+01:00) To: [email protected] Subject: Re: [nanovna-users] New file uploaded to [email protected] I guess as an intellectual exercise it might be fun to know the accuracy as compared to a Keysight PNA-X series but practically speaking, if you are looking for that kind of accuracy from a credit card sized Chinese rip-off than I have a couple of bridges I want to sell you. Regardless how a $55 “toy” stacks up against a $75,000 lab instrument, for most of us we already know enough.We know it meets its frequency accuracy spec. We know it calibrates OSLT perfectly out to 900 MHz. I can tell you it tracks my Rigol Spectrum Analyzer/Tracking Generator/Return Loss Bridge within one dB out to 900 MHz and down to 40 dB Return Loss.If you are looking for 0.1 dB accuracy at 60 dB RL then an open frame, unshielded toy is probably not going to satisfy you.If you are an amateur radio operator who builds stuff and thinks 25 dB return loss and 1 dB accuracy is the cat’s meow ( I am one of those ) then this is manna from heaven. If you are a broadcast professional responsible for multi-tower directional arrays, 900 MHz STLs, and FM broadcast stations (I am also one of those) then it still represents a window on your system that I and most of my clients could not afford until this point.I enjoy and join enthusiastically in your discovery journey to find out what makes this gadget tick and how well. But for those who don’t have the perspective of a high end VNA aficionado? who are waiting to see if it is accurate to -60 dB…. we should probably tell them their $55 is a worthy investment and they should just get one and play and learn.WA8TODOn Aug 10, 2019, at 5:27 PM, alan victor <avictor73@...> wrote:Thank you Tuck.A fundamental question that needs further investigation is the accuracy of the VNA instrument.This has not been addressed nor have I seen a specification in the document. The basic instrument configured as a one channel, one port VNA or antenna analyzer has the usual errors that are corrected by the firmware. The basic errors are the reflection tracking, the source match and the directivity. The nanoVNA uses a resistive bridge not a directional coupler. I need to think about how to get a handle on these errors uncorrected and then corrected. As you know, the level of error correction is dependent on the quality of the calibration standards.I suspect the original designer has worked through those details. They may even be in some of his software comment sections.This is a topic for future work.Alan

On 8/10/19 5:57 PM, Warren Allgyer wrote:

I guess as an intellectual exercise it might be fun to know the accuracy as compared to a Keysight PNA-X series but practically speaking, if you are looking for that kind of accuracy from a credit card sized Chinese rip-off than I have a couple of bridges I want to sell you. Regardless how a $55 “toy” stacks up against a $75,000 lab instrument, for most of us we already know enough.

We know it meets its frequency accuracy spec. We know it calibrates OSLT perfectly out to 900 MHz. I can tell you it tracks my Rigol Spectrum Analyzer/Tracking Generator/Return Loss Bridge within one dB out to 900 MHz and down to 40 dB Return Loss.

If you are looking for 0.1 dB accuracy at 60 dB RL then an open frame, unshielded toy is probably not going to satisfy you.

If you are an amateur radio operator who builds stuff and thinks 25 dB return loss and 1 dB accuracy is the cat’s meow ( I am one of those ) then this is manna from heaven. If you are a broadcast professional responsible for multi-tower directional arrays, 900 MHz STLs, and FM broadcast stations (I am also one of those) then it still represents a window on your system that I and most of my clients could not afford until this point.

I enjoy and join enthusiastically in your discovery journey to find out what makes this gadget tick and how well. But for those who don’t have the perspective of a high end VNA aficionado who are waiting to see if it is accurate to -60 dB…. we should probably tell them their $55 is a worthy investment and they should just get one and play and learn.

WA8TOD


On Aug 10, 2019, at 5:27 PM, alan victor <avictor73@...> wrote:

Thank you Tuck.

A fundamental question that needs further investigation is the accuracy of the VNA instrument.

This has not been addressed nor have I seen a specification in the document. The basic instrument configured as a one channel, one port VNA or antenna analyzer has the usual errors that are corrected by the firmware. The basic errors are the reflection tracking, the source match and the directivity. The nanoVNA uses a resistive bridge not a directional coupler. I need to think about how to get a handle on these errors uncorrected and then corrected. As you know, the level of error correction is dependent on the quality of the calibration standards.

I suspect the original designer has worked through those details. They may even be in some of his software comment sections.

This is a topic for future work.

Alan

On Aug 10, 2019, at 5:27 PM, alan victor <avictor73@...> wrote:

Thank you Tuck.

A fundamental question that needs further investigation is the accuracy of the VNA instrument.

This has not been addressed nor have I seen a specification in the document. The basic instrument configured as a one channel, one port VNA or antenna analyzer has the usual errors that are corrected by the firmware. The basic errors are the reflection tracking, the source match and the directivity. The nanoVNA uses a resistive bridge not a directional coupler. I need to think about how to get a handle on these errors uncorrected and then corrected. As you know, the level of error correction is dependent on the quality of the calibration standards.

I suspect the original designer has worked through those details. They may even be in some of his software comment sections.

This is a topic for future work.

Alan