[hpsdr] Level calculation error in Two Tone Test generation routine

[Warren C. Pratt]

Hi Kjell,

I believe you are referring to the transmitter power meter and yes, I 
agree.  I am not familiar with that code.  I expect that there is some 
firmware that "samples" the voltages and then some instantaneous value 
is calculated in software and sent to the meter ... not sure.  There may 
be some constraints on what can reasonably be done ... again, don't know.

The S-meter code is part of the DSP software and I did write that.  I 
believe that the peak and average readings work well over the frequency 
range of interest.  As a test, tune in an AM broadcast station which is 
modulated at approximately 100%, or use a signal generator set up this 
way.  Note that the Peak reading is 6dB higher than the average reading, 
as it should be.

Relating this to a previous post, the peak/average power is 4X while the 
peak/average voltage is 2X.

73,

Warren  NR0V


On 11/24/2016 8:52 AM, Kjell Karlsen wrote:
> ***** High Performance Software Defined Radio Discussion List *****
>
> High all.
>
> In the start of this tread I was very confused as I did not see the 
> problem clearly but now we are back to basic!
>
> But the measured and indicated power i PSDR is not very accurate. For 
> me it seems as it is the PEP that it is meant to indicate but very 
> difficult to read due to the fast movement of the instrument needle. I 
> think there should have a possibility to select between PEP and Average.
>
> 73,Kjell.
>