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SDR# with Airspy Mini via Spyserver: bandwidth questions #sdrsharp #spyserver #raspberrypi


Bob Dengler
 

At 4/2/2020 09:42 AM, you wrote:
On Thu, Apr 2, 2020 at 03:50 PM, Niek wrote:
Why is this?

<https://groups.io/g/airspy/search?q=spyserver+bandwidth>https://groups.io/g/airspy/search?q=spyserver+bandwidth
I have the same problem: WFM BW won't go higher than 187.5 kHz, & NFM no higher than 11.718 kHz. I've also searched the archives & found no solution that works so I assume it's a limitation of either Spyserver or SDR#. I doubt that network BW is the issue because the limits are enforced even when Spyserver is running on the same computer as SDR#.

11.718 kHz is barely wide enough for listening to typical 5 kHz deviated FM voice. However, if better audio quality is needed I have found a workaround for NFM mode: use WFM for listening to NFM signals so the IF BW can be set wider, set the SDR# audio output to a virtual audio cable, & use KG-Tone for the noise squelch.

Bob NO6B


prog
 


Bob Dengler
 

At 4/2/2020 03:59 PM, you wrote:
From the archives:

<https://groups.io/g/airspy/message/23907>https://groups.io/g/airspy/message/23907
https://groups.io/g/airspy/message/24332
Thanks prog - that fixed both the NFM & WFM BW issues! I think I missed it because I was looking for settings to change in Spyserver, not SDR#. I honestly spent quite a bit of time looking for the solution & couldn't find it, so thanks for putting up with us search-challenged people.

Bob NO6B


prog
 

You are welcome. Maybe we need to write it in the wiki section.


Niek
 

Hi Prog,

Thank for taking your time.
Could you please complete your answer and tell me where to add this line?
<add key="minReducedNarrowBandwidth" value="9000" />
From Bob's reply, I take that it's in the config of SDR# somewhere?

What's the reason behind this?
It worked out of the box with RTL-SDR, this behaviour is only with the Airspy mini.
It can't be my network limiting, I'm around 300 kB/s and can pump that up to 1,2 MB/s when increasing the IQ format.


prog
 

On Fri, Apr 3, 2020 at 07:37 PM, Niek wrote:
From Bob's reply, I take that it's in the config of SDR# somewhere?
Obviously.

What's the reason behind this?
Sample rate and decimation maths.


Bob Dengler
 

At 4/3/2020 12:20 AM, you wrote:
Hi Prog,

Thank for taking your time.
Could you please complete your answer and tell me where to add this line?
<add key="minReducedNarrowBandwidth" value="9000" />
From Bob's reply, I take that it's in the config of SDR# somewhere?
SDRSharp.exe.Config:

<add key="minReducedNarrowBandwidth" value="15000" />
<add key="minReducedWideBandwidth" value="200000" />

Bob NO6B


Niek
 

Thanks Bob.
I've changed the default values of 9000/120000 to 15000/200000.
NFM now goes to 23,437 kHz, which activates my OCD but is more than wide enough.
WFM still goes to 187,5 kHz though, so the 200000 in config seems to be ignored.

And what happened to my opening post?
Someone deleted it?