Plotting signal strength


I’m trying to plot singnal strength (like s-meter) on the Scope sink
from a file recorded by rtl_sdr. And I’m not getting what I expect,
it’s either frequency is off or what is being plotted doesn’t correlate
with what I see on waterfall. I’m using frequency xlating filter
to shift frequency -> low pass filter -> rational resempler -> complex
to mag^2. Grc is included.