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.

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Offset on S21 below -15dB

METRA FLORENT 2021/04/27 10:00

Hi everybody,

i have an issue with my SAA-2N.
I wanted to measure an attenuator of -30dB, and i found -28dB on my SAA-2N. I checked the attenuator on a R&S ZNB, and the measure was -30dB!
So, i measured a step attenuator from 0dB to -50dB on the SAA-2N and on the ZNB at 350MHz on both.

Look at the curve, below -15dB, there is an offset of around 2dB. It is the same issue without any calibration, and it is not dependent to the frequency.

Do you have an idea ? Is it a bug software or an hardware issue ?

Thanks for your help,

Best 73's Florent, F4CWN.

DiSlord 2021/04/27 21:18

Update fw
or set output power STIMULUS->CFG SWEEP-> ADF4350 TX POWER to 0 and save to 0 slot
after device on switch back to need value

METRA FLORENT 2021/04/28 13:26

I updated the firmware, same problem. If I set output power to 0, the problem appears between -5 and -6dB.

It look like the gain control of the baseband amplifier changed


DiSlord 2021/04/28 06:40

You can check Config->DMSG
See bbgain3 value, should be ~-20dB (on error you see ~-18.5dB)

Or you can try my variant:
Unpack archive,and instal correct version

METRA FLORENT 2021/04/28 08:28

BBGAIN3 is -17.94

Is it normal ? What is BBGAIN ? Is there any documentation about this parameter ?

I will try the experimental file ...



DiSlord 2021/04/28 10:57

В среду, 28 апреля 2021 г., в 08:28, МЕТРА ФЛОРЕНТ пишет:

> BBGAIN3 -17,94

No, this mean overflow on calibration internal attenuator (should be near -20dB) and you see this 2dB shift near 18dB.
Fixed in last fw or reduce output power at startup (save in 0 slot settings vs 0 ADF output).

METRA FLORENT 2021/04/28 13:31

When is done the calibration on internal attenuator ? At startup ?

I tried this firmware ( ) but BBGain was also -18 dB,

i also tried Dislord Firmware ( ) , and this firmware fixed the problem !!

I tried also with last firmware ( nanovna-v2-20201013-v2_74.bin ) work also !!

At the beginning i used a firmware from a tutorial of a french guy, i don't understant because it look like the same as nanovna-v2-20201013-v2_74.bin, but not working !(bbgain -18dB !)

Shame on me not using original files on official website !

Thanks all for your great help !

Best 73's Florent, F4CWN

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