Hi Andy, A silly question from someone struggling to understand, but the ^2 below, 20log... and V^2/R (for ex) are all related ? We're looking at voltages and comparing powers? noise, it will increas
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 mH
Hello Bill, if you reduce the data from 16 bit to 12 bit teh way you did, you actually reduce sensitivity by 24dB (you loose the sample values less than 16/65536) and reduce the dynamic range from 96
First of all, thanks to everyone for the great comments, much appreciated. I don't have a 24-bit ADC here to run Jim's test but tried another experiment with interesting results. Tonight Stefan, DK7F
Bill - Its not that bad. Consider a weak signal with a peak to peak amplitude of less than one quantisation step, in the presence of larger amplitude noise that toggles the first few bits of the A/D.
Hi Bill, Audio afficionados are high on opinion but notoriously hard-put to show statistically significant discrimination in true ABX or ABC scenarios; I wouldn't be using them as any sort of criteri
Dear Bill, Andy, LF Group, It seems to me it should be quite easy to subject this to practical testing. First, using SpecLab etc., measure the SNR of a weak signal in the presence of noise, with the
Well Alberto, this morning I have egg on my face, as we English-speakers sometimes say :-) Late last night (when I was half asleep) I posted a small .jpg showing 2 cropped screen captures, top using
On 12/2/2011 4:53 PM, Bill de Carle wrote: My question is this: In a practical situation with low QRN/QRM, would going to a 24-bit ADC soundcard result in an ability to detect a weak LF signal that w
When you add non coherent sources like noise, you have to add power, or mean square values. So a Noise voltage of RMS = 16 (the input noise) added to noise of RMS = 1 (Nq) = SQRT(16 * 16 + 1 * 1) = R
Dear Andy, Bill, LF Group, codecs in soundcards are SD type. A sigma delta converter in its simplest form is a one bit D/A runing at a very fast sampling rate. Reminds me of the old DOS era, pre- sou
We have seen a tendency to use ultra narrow bandwidths to coax out weak signals not otherwise discernable. This calls for enhanced frequency stability at both ends, but that is not the only factor in
Which is exactly the point I was making earlier. When a signal is buried in noise, and subject to post processing that decimates the sampling rate, the initial quantisation noise becomes irrelevant S
