[hpsdr] Signal level discrepancy RA Utility / Multimeter

[Warren C. Pratt]

Hi Wolfgang,

The S-meter reads the correct peak signal level (dBm) when in "Signal" 
mode and the correct average/rms SIGNAL level when in "Sig Avg" mode.  
There is an error, that I will try to remember to correct in the next 
release, when reading the average/rms NOISE in the "Sig Avg" mode.  At 
present, due to the way the computation is done, the meter will report 
random noise 2.51 dBm lower than actual value although it reports signal 
levels correctly.  To get the ultimate accuracy, I'd suggest doing a 
Level Calibration as found on the Setup => General/Calibration tab; 
however, I my experience has been that the default calibration is quite 
good.

The method wdsp.CalculateRXMeter is found in the file dsp.cs and it in 
turn calls the DSP (WDSP) to get a meter value.  A calibration factor 
then needs to be added to that value before display.  In this case, the 
FLEX manual is correct about what the S-meter reports. However, please 
be aware that our DSP code is 100% different than FLEX as are many other 
parts of the code; so, in many cases the FLEX manual will not be correct.

73,
Warren  NR0V