SDRUno S-Meter Reading?
Posted: Sun Jul 15, 2018 4:42 pm
First I assume that the data for the meter is picked up close to where the audio is handed off to the PC. I really am not an engineer but an amateur customer. When I vary the audio bandwidth the reading on the S-Meter changes. Very strange. Some Hams may believe that it is true signal strength when it is really a measure of what they hear (or see - SSTV). As such the reading is not an engineering value but a perception measure. We are hopefully taught to think of signal-to-noise ratio. Grab the RF gain not Audio gain. Once you allow the AGC to do its thing it will smooth out the signal and suppress some of the intelligence carried by the signal. Inflections from the speakers voice are compromised. Perhaps that is why some radios sound so flat. So the S-meter can also be fooled with a measurement that really does not reflect the real readability of the signal. Grab the S-Meter signal data outside of the AGC calculation. I wonder if some radios just grab the smoothed AGC data and display is as a signal strength.
Lots of differences and perhaps the Governing Body, The ARRL, should develop some standards otherwise we simply go down another fictional path similar to the contest 59 rule.
N3HKN
Lots of differences and perhaps the Governing Body, The ARRL, should develop some standards otherwise we simply go down another fictional path similar to the contest 59 rule.
N3HKN