Beware of cheap underperforming clones

As of 2022 there are many badly performing clones on the market. V2/3GHz NanoVNA uses parts like ADF4350 and AD8342 which are costly and clones have been cutting costs by using salvaged or reject parts.

See official store and look for V2 Plus4/V2 Plus4 Pro versions only to avoid getting a bad clone. We have stopped selling V2.2 versions since October 2020, so all V2 hardware that are not Plus or Plus4 are not made by us and we can not guarantee performance.

NanoVNA V2 Forum

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Applying Calibration Crashes the software

Barrett Poe 2020/06/18 20:47

I received my v2 this week and I have been working on getting a two port calibration on it, but I have not been completely sucessful- everytime I try to apply the calibration, the software crashes and I have to retake the data. I have tried three times with different frequency ranges and number of points, but I have only been able to get a one port calibration to work. Any suggestions?

OwO 2020/06/19 12:44

Only SOLT (T/R) is supported because it is a T/R VNA. The full two port
calibration in the software is an artifact from support for different
hardware in the past. I'm considering adding in two port one path
calibration, that way you can measure 4 S parameters by reversing the DUT.

On 19/06/2020 11:47, Barrett Poe via wrote:

ok1vaw 2020/06/19 09:45

I have not been thinking if it adds something better against the
built-in SWR bridge, but is there any calibration in case of using
external directional coupler and using port 1 as a source and port 2 as
a detector?


Dne 19.06.2020 v 6:44 Gabriel Tenma White napsal(a):

iz1fks 2020/06/19 05:23

Sorry, but I haven't understood. If the full calibration is performed at the port1 and the path is calibrated using through it should be possible to measure both S11 and S12. Reversing the EUT connection is possibile to measure the other 2 S parameters, isnt'it?



OwO 2020/06/19 20:49

Yes, this is true, but normally with the ordinary SOLT calibration it's
not possible to calibrate out the port 2 match error in a T/R VNA. Only
port 1 is fully calibrated out, and S21 is a simple response calibration
that normalizes the gain and phase to 0dB/0 degrees for the thru
measurement. However there is a technique that allows you to calibrate
out the imperfect port 2 match if you measure the DUT both ways. This
isn't yet implemented in NanoVNA-QT, but the scikit-rf python library
has it:

Why is it not possible to calibrate out port 2 match error? When
measuring the thru standard, we did discover the port 2 reflection
coefficient. However, it's not possible to calculate how this will
affect the DUT's response. We know how much signal is incident on port
2, since it has a receiver. We know how much signal is reflected from
port 2, because we know its reflection coefficient. However, we don't
know the S12 of the DUT, so we don't know how much of this signal goes
back to port 1. By measuring the DUT both ways, we learn of its S12 and
S21, which allows you to formulate a system of equations to solve for
the true S parameters of the DUT without the influence of port 2 match
error. This still depends on measurements being stable after unplugging
and reversing the DUT, so you need connectors with good repeatability
and phase stable cables.

On 19/06/2020 20:23, iz1fks wrote:

iz1fks 2020/06/19 11:37

thank you for the great explanation, sure it will be useful to have it implemented as well in order to characterize a device with a complete set of s parameters
(e.g. for a model simulation)

Juan Manuel Muñoz 2020/06/19 21:19

If you are using windows 10 give the executable at startup
administrator permissions so that it can write the calibration files

El vie., 19 jun. 2020 a las 6:06, Barrett Poe via (<W0ASB=>) escribió:

Louis Wilen 2020/11/17 20:05

FWIW, I'm seeing the same behavior under Win10. I haven't tried in other environments.

A one port cal succeeds.


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