Re: Spurs with NaP3


ab2tc
 

I realize it's overkill, and in practice I never use that high resolution. But these two spurs start to become visible with a setting of 8192.

Can't wait for the next release with scaleable resolution.

AB2TC - Knut

--- In Elecraft_K3@..., "Larry" <n8lp@...> wrote:

They could be from anywhere. 262144 (256K) is a huge overkill. The higher bin numbers should only be used at the narrowest spans, and even then 256K is overkill. TRX-Pan is 64K max, PowerSDR is 4K fixed, and the P3 is 450 samples.

As a frame of reference, the Resolution Bandwidth (RBW) of the P3 at 3kHz span is about 7Hz. The RBW of NaP3 at 256K bins is about 0.7Hz... ten times lower. A setting of only 32K in NaP3 would give comparable RBW to the P3 at its narrowest span. The next release will scale the bins from 4K at the widest span to 128K at the narrowest span, but even this is probably overkill. A future release will probably allow you to select a specific number of bins for each zoom setting.

73,
Larry N8LP



--- In Elecraft_K3@..., "Knut Spang" <ab2tc@> wrote:

Hi,

I am curious about the spurs that appear when I turn up the Spect setting in the DSP setup menu. The spurs don't increase in strength but the noise floor decreases so they become more visible. Here is what I see with the Spect set to 262144, the K3 disconnected and instead a good quality dummy load connected to the LP-pan BNC input:

http://ab2tc.getmyip.com:8000/pictures/spurs.png

Where do those come from?

AB2TC - Knut

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