Green Horizontal Bar in main display

[Jim Schrempp]

I've searched and read and can't find a good description of what the horizontal green bar to the right of the frequency display is showing me. This is the bar with a scale of -100 to 0 and a label below that with dBFS. Can someone give me an idea of how the value of this bar is calculated?

Jim

[Kevin Reid]

On Thu, Sep 15, 2016 at 3:49 PM, Jim Schrempp <j...@jimschrempp.com> wrote:

I've searched and read and can't find a good description of what the horizontal green bar to the right of the frequency display is showing me. This is the bar with a scale of -100 to 0 and a label below that with dBFS. Can someone give me an idea of how the value of this bar is calculated?

It is the received signal power, within the bandwidth of the currently selected mode.

dBFS means decibels relative to "full scale", i.e. an amplitude of 1.0 obtained from the RF hardware. This unit is the best Gqrx or any simple SDR software can do since there is no available calibration to absolute signal levels measured in electrical units. (If there were, this figure could be instead measured in dBm.)

[Jim Schrempp]

Thanks Kevin.

Does this mean it is the average signal power within the light grey vertical stripe on the FFT display? Or is it average across the entire FFT display?

Jim

[Kevin Reid]

On Thu, Sep 15, 2016 at 4:55 PM, Jim Schrempp <j...@jimschrempp.com> wrote:

Does this mean it is the average signal power within the light grey vertical stripe on the FFT display? Or is it average across the entire FFT display?

The former. You can see that if you change the mode or the filter bandwidth the level will change correspondingly.