[hpsdr] Higher sampling speeds

[Alberto I2PHD]

Are there any plans to increase the final sampling rate(s) in Mercury after the DDC ?
The recent additions of 96 abd 48 kHz are certainly useful, but as much useful and
possibly more could be the addition of higher speeds, like 250, 500, 1000 and 2000 kHz.

Tests done with Perseus and by Phil with his QS1r have shown that a sampling rate of
2 Mhz is manageable without much problems. I have a 1.5 GHz laptop, with a single core
Mobile Pentium that can handle Perseus at 1 MHz sampling rate without audio disruptions,
and a decent waterfall speed. This demonstrates that you don't need stratospheric
computing power to cope with higher sampling speeds.

And the objection that those sampling rates are not multiple of the sound card rates,
has no much relevance. A fractional ratio resampler can be coded rather easily, with
spurs down to -100dB.

Having a larger chunk of the band visible in the waterfall at once could be useful, e.g.,
when using Mercury together with a down converter for the 144 MHz band.
Another use of a wider chunk of band could be the recording into an I/Q WAV file of the
entire segment of the Medium Waves, to be later on replayed for identification of DX
stations. This is what is most sought of by the MWLs and SWLs.
And I am sure there could be much more applications for a 2 or even 4 MHz bandwidth.

73  Alberto  I2PHD