I can't find any specific information about RBW. There is only very general information: a very narrow band!
Have somebody more specific data?

On 20/07/2022 18:24, j4wagner@gmail.com wrote:
> I can't find any specific information about RBW. There is only very general
> information: a very narrow band!
> Have somebody more specific data?

My understanding that it is the bandwidth over which the signal power is
measured (totalled, if you like). In a VNA it would mean you need to make more
measurements to cover a given range. Think notch measurements - narrower
delta-F, but slower.

Doubtless someone will have a better explanation.

Cheers,
David
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*Ruth Bader Winsburg ?*

It's somewhat firmware dependent (it's changed over the versions), and I don't track the V2 firmware versions
About 1 kHz, though, although I think there are versions with narrower measurement bandwidth.
On the NanoVNA the original software captured 48 samples at 48 kHz (i.e. 1 millisecond) and did a direct sin/cos multiply and integrate.  So the effective "receiver filter" is a sin x/x corresponding to a 1 millisecond integration time.  There are firmware versions which take multiple measurements and average them (sort of the equivalent of video bandwidth on a spectrum analyzer)

It would affect the SNR of the underlying measurements.   It's a bit complex, because there's also quantization noise to consider.

The whole implementation on the NanoVNAs, both 1 and 2, is different from a traditional VNA, so I'd not try to directly compare.  But if you use 1 kHz, you're in the right ballpark.

Hello, thanks for your answere. I found the information on the tindie site:
*IF bandwidth: adjustable from 0.8kHz to 10kHz (V2 Plus4 Pro)*
https://www.tindie.com/products/hcxqsgroup/nanovna-v2-plus4/
Regards
Jacek

The calculation It is essentially a single bin of an FFT. The more
samples you use (equivalent increasing the timespan), the narrower the
bandwidth.

Op 21-7-2022 om 16:51 schreef Jim Lux:

>
> It's somewhat firmware dependent (it's changed over the versions), and
> I don't track the V2 firmware versions
> About 1 kHz, though, although I think there are versions with narrower
> measurement bandwidth.
> On the NanoVNA the original software captured 48 samples at 48 kHz
> (i.e. 1 millisecond) and did a direct sin/cos multiply and integrate. 
> So the effective "receiver filter" is a sin x/x corresponding to a 1
> millisecond integration time.  There are firmware versions which take
> multiple measurements and average them (sort of the equivalent of
> video bandwidth on a spectrum analyzer)
>
> It would affect the SNR of the underlying measurements.   It's a bit
> complex, because there's also quantization noise to consider.
>
> The whole implementation on the NanoVNAs, both 1 and 2, is different
> from a traditional VNA, so I'd not try to directly compare.  But if
> you use 1 kHz, you're in the right ballpark.
>

Yes, statistic rules!

Hi Jim, thanks for info. Regard