## Re: [Kaffeine-user] [Fwd: Kaffeine : Signal and SNR/CVS]

 Re: [Kaffeine-user] [Fwd: Kaffeine : Signal and SNR/CVS] From: Hendrik Sattler - 2005-05-22 00:22:03 ```Am Samstag, 21. Mai 2005 20:34 schrieb J=FCrgen Kofler: > I have a question: In the channels dialog panel of Kaffeine one will > =A0find a signal meter and a signal to noise ratio meter. > =A0I only know of SNR meters showing db values. What does it mean, if > =A0SNR is 71% for example? 71% of what? ;) SNR =3D signal/noise You can measure in in dB or not, dB simply means SNR[dB] =3D 10 * SNR[B] =3D 10 * lg(SNR) Since they probably measure powers: SNR[dB] =3D 20 * lg(signal[V]/noise[V]) Wikipedia is very informative about this. =A0 > =A0Same goes for the signal meter. I get =A07%. What does it mean? What is > =A0100%. 100% is the expected maximum power for DVB-T. You'll surely never get that. > =A0I am a little confused, since I get "only" 7% signal but 71% SNR.... 71/100 =3D (7/100) / x <=3D> x =3D 7/(71*100) ~=3D 0,1% You don't have a strong signal but not much noise either :) HS ```

 Re: [Kaffeine-user] [Fwd: Kaffeine : Signal and SNR/CVS] From: Hendrik Sattler - 2005-05-22 00:22:03 ```Am Samstag, 21. Mai 2005 20:34 schrieb J=FCrgen Kofler: > I have a question: In the channels dialog panel of Kaffeine one will > =A0find a signal meter and a signal to noise ratio meter. > =A0I only know of SNR meters showing db values. What does it mean, if > =A0SNR is 71% for example? 71% of what? ;) SNR =3D signal/noise You can measure in in dB or not, dB simply means SNR[dB] =3D 10 * SNR[B] =3D 10 * lg(SNR) Since they probably measure powers: SNR[dB] =3D 20 * lg(signal[V]/noise[V]) Wikipedia is very informative about this. =A0 > =A0Same goes for the signal meter. I get =A07%. What does it mean? What is > =A0100%. 100% is the expected maximum power for DVB-T. You'll surely never get that. > =A0I am a little confused, since I get "only" 7% signal but 71% SNR.... 71/100 =3D (7/100) / x <=3D> x =3D 7/(71*100) ~=3D 0,1% You don't have a strong signal but not much noise either :) HS ```