SW2 FFT Resolution


Fenu
 

Hi,
One thing that I miss in the SW2 is the possibility to set the FFT Resolution. Or have I overlooked this possibility for years?

Regards
Fernando


Pete
 

Fernando
For me the IF SPECTRUM window for each receiver gives a nice hi resolution 48.0kHz wide FFT.

Pete


Pete
 

I forgot to mention that the IF SPECTRUM window span can be reduced to 187Hz.

Pete


Paul White
 

Span is not the same as resolution.

Now, an option with resolution on the order of 1 Hz (spectrum & WF) really would be something for carrier offset detection/measurement!


Neil Smith G4DBN
 

I use Spectrum Lab to get milliHertz or finer resolution on the audio stream from my DUO.  The IF waterfall in 192 kHz with the DUO is 2.9 Hz per bin.  Using Spectrum Lab with an FFT length of 262144 and decimation of x4 gets me down to 69 mHz noise bandwidth (46 mHz bin width) with an update of one pixel every five seconds at 75% overlap.

This is a weak harmonic of a stable crystal oscillator as received on my DUO into Spectrum Lab.

Neil G4DBN

On 20/01/2021 22:04, Paul White wrote:

Span is not the same as resolution.

Now, an option with resolution on the order of 1 Hz (spectrum & WF) really would be something for carrier offset detection/measurement!



Paul White
 

On Wed, Jan 20, 2021 at 10:50 PM, Neil Smith G4DBN wrote:
one pixel every five seconds at 75% overlap
Isn't it true, Neil, the SDR software could achieve even better update frequency and resolution with multiple overlap?
Don't know what the processing overhead would be.