Bill,
thanks for sharing your results about comparing 12- vs 16-bit QRSS
reception.
You showed that, when the reception mode allows a very great
reduction in the sampling rate,
going down in the mHz range, the processing gain thus obtained makes
somewhat irrelevant
the finesse of the original amplitude resolution, when digitizing.
And this was your original
question, which you have adequately answered to. For this kind of
applications, a 24-bit
sound card gives no practical advantages over a 16-bit one.
Just a note. This result cannot be generalized to SDR in its broader
sense. If you cannot
dig into the noise with mHz resolution, but when what you want or
need to achieve is e.g.
an SSB reception done with SDR technology, you cannot have a final
sampling rate much lower
than, let's say, 8 kHz. In this case it is not possible to count on
such a big processing gain.
It is for this kind of applications that 24 bits show an edge over
16 bits. When you need
a dynamic range of 120 dB in such a bandwidth, you badly need the
more bits you can
obtain from your digitizer....
To mention still another English (or is this more American ?)
proverb : YMMV
Your Mileage May Vary :-)
73 Alberto I2PHD
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