Re: CW Skimmer decoded bandwidth


jdow
 

24 kHz if you ignore decimation anti-aliasing filters. 22 kHs is with the anti-aliasing filters.

{^_^}

On 20200531 06:46:11, Max wrote:
Hi Grant
Had some time to re-think this over lunch. Surely the ultimate bandwidth ib=n CWS with SDRC should only be to do with the sample rate of the VAC? I checked my VAC and it was set to 48kHz, which would have usually explained the bandwidth seen in CWS, because as far as I know one would expect a decode bandwidth of half of 48kHz (Nyquist?) = 24 kHz (yes, not 22!).
So I reset my VAC to 192kHz, and also changed CWS setting in SDRC to match, 192 kHz, hoping I would see decode bandwidth in CWS of 1/2 x 192 = 96 kHz. But no, I still see decode bandwidth of 24 kHz.
So at that point I have realised I am missing something I think. Only correction for me is the 22kHz I mentioned earlier is obviously 24 kHz.
Anyway, if you find any more I would be interested to know myself, so I await further input from those that understand it better than I do.
73
Max
On Sun, May 31, 2020 at 11:21 AM, Grant Rawstorn VK2LX wrote:
Hi Max and Bill
It appears to me that when configured in Softrock-IF mode CW Skimmer
defaults to 48KHz sampling (even with 192 selected) and it is only possible
to see 24 KHz of decoded bandwidth. Bill am I right in assuming that you are
not using Softrock-IF as the selected radio in CWS?
Cheers Grant

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