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<p>Hi Ari,</p>
<p>"Sig Avg" is the correct S-meter setting to read noise. "Signal"
gives you a peak reading (appropriate for signals) while "Sig Avg"
gives you an average reading.</p>
<p>The S-meter reads the noise power within the width of the
bandpass filter, 1.5Khz in your example. The panadapter shows the
noise power within each frequency "bin". The width (bandwidth) of
the bin is displayed on the Setup/Display/RXx tabs. To correctly
read noise on the panadapter, you should choose the "Average"
detector and either "None" or "Recursive" as your averaging mode.
If the "1Hz BW" box is checked, the result displayed on the
panadapter will be normalized to a 1 Hz bandwidth. The noise
readings of the S-meter and the panadapter are therefore related
by the equation:</p>
<p>S_reading = Panadapter_reading + 10*log10 (bandpass_width /
panadapter_bin_width)</p>
<p>I realize all that is a bit complicated. However, if you master
the various settings, your SDR is an excellent spectrum analyzer
for accurately measuring both signals and noise.</p>
<p>73,</p>
<p>Warren NR0V<br>
</p>
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<p class="MsoNormal"><span lang="IS">Hi<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="IS"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="IS">On 6 meter I have noise
floor -132 dBm same time Smeter say -114 dBm<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="IS">and S meter say 5.1
bandwidth is 1.5k<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="IS">RX1 Meter is set to Sig
Avg, I get higher reading with Signal.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="IS">Why do S meter not say same
reading as Panadapter ?<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="IS">And how can I have S meter
5 With only noise of -132 dBm ?<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="IS">And where do Smeter get
-113 dBm ?<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="IS">And why do we have 24 hours
in day </span><span style="font-family:"Segoe UI
Emoji",sans-serif" lang="IS">😊</span><span lang="IS"><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="IS"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="IS">Ari TF3ARI<o:p></o:p></span></p>
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