I have made a comparative measurement yesterday using a Nano-VNA V2 Plus4 and a HP-8753E.
I needed to measure a certain length of an RF cable at work. I had to use Port Extensions (i.e. Electrical Delay on VNA) and set the correct velocity factor, etc...

1. On the Nano VNA the delay had to be set to double than on the HP. Maybe the Nano VNA reports the round-trip delay? (i.e.. The cable was open at one end so full-reflection)
I can live with that, but the reported length was incorrect.

2. Instead of 10600mm the Nano VNA reported 106mm. (i.e. ~5m cable considering the double delay problem).

3. On the HP I have an accuracy of 0.5mm for the length measurement while on the Nano VNA it's reduced to 10cm due to this bug.
I can live with any accuracy in range of mm on the Nano VNA but I don't know if that is hw/sw realisable at this price point.

NOTES:
- I have an original Nano VNA V2 Plus 4 - just recently acquired via the official webshop
- the fw version is: git-20210530-412578c
- build time: Nov 3 2021

I checked the release notes for more recent firmware but there is no mention of this bug

Did you check with the official last firmware from nanorfe?


Le mar. 1 mars 2022 à 14:47, <e.moldovan@gmail.com> a écrit :

> I have made a comparative measurement yesterday using a Nano-VNA V2 Plus4
> and a HP-8753E.
> I needed to measure a certain length of an RF cable at work. I had to use
> Port Extensions (i.e. Electrical Delay on VNA) and set the correct velocity
> factor, etc...
>
> 1. On the Nano VNA the delay had to be set to double than on the HP. Maybe
> the Nano VNA reports the round-trip delay? (i.e.. The cable was open at one
> end so full-reflection)
> I can live with that, but the reported length was incorrect.
>
> 2. Instead of 10600mm the Nano VNA reported 106mm. (i.e. ~5m cable
> considering the double delay problem).
>
> 3. On the HP I have an accuracy of 0.5mm for the length measurement while
> on the Nano VNA it's reduced to 10cm due to this bug.
> I can live with any accuracy in range of mm on the Nano VNA but I don't
> know if that is hw/sw realisable at this price point.
>
> NOTES:
> - I have an original Nano VNA V2 Plus 4 - just recently acquired via the
> official webshop
> - the fw version is: git-20210530-412578c
> - build time: Nov 3 2021
>
> I checked the release notes for more recent firmware but there is no
> mention of this bug
>
>
>
>
>

Not yet, that would be the next step.

As said, I looked at the fixes since my FW version and didn't see any indication this bug was reported or fixed.

It's quite an important feature so I was expecting people to notice it.

Check the sweep bandwidth and the number of points. I suspect you are seeing aliased results.
On Tuesday, March 1, 2022, 08:58:38 AM PST, F1RVC <f1rvc.patrice@gmail.com> wrote:

Did you check with the official last firmware from nanorfe? 

Le mar. 1 mars 2022 à 14:47, <e.moldovan@gmail.com> a écrit :

I have made a comparative measurement yesterday using a Nano-VNA V2 Plus4 and a HP-8753E.
I needed to measure a certain length of an RF cable at work. I had to use Port Extensions (i.e. Electrical Delay on VNA) and set the correct velocity factor, etc...
1. On the Nano VNA the delay had to be set to double than on the HP. Maybe the Nano VNA reports the round-trip delay? (i.e.. The cable was open at one end so full-reflection)I can live with that, but the reported length was incorrect.

2. Instead of 10600mm the Nano VNA reported 106mm. (i.e. ~5m cable considering the double delay problem).

3. On the HP I have an accuracy of 0.5mm for the length measurement while on the Nano VNA it's reduced to 10cm due to this bug.
I can live with any accuracy in range of mm on the Nano VNA but I don't know if that is hw/sw realisable at this price point.

NOTES:
- I have an original Nano VNA V2 Plus 4 - just recently acquired via the official webshop 
- the fw version is: git-20210530-412578c
- build time: Nov 3 2021

I checked the release notes for more recent firmware but there is no mention of this bug

You are off by a factor of 100 because the velocity factor needs to be input as percentm not a decimal fraction.  e.g. a VF of 0.71 should be input a 71

Thanks, I didn't think about that. On the HP this is entered like .xxx
I'll try it out!!!

Thanks, I didn't think about that. On the HP this is entered like .xxx
I'll try it out!!!