- A little hint on using the "Ref"erence Level, and "Amp"litude controls
located in the right hand side of the main display. If the background
is green and the signals bright yellow or red then you probably have the
"ref" and "amp" controls set wrong. Both of these controls are in dB.
The "ref" is the reference level for the largest signal being received.
I find that with my sound card this should be about -10. The "Amp" is
the amplitude range over which the signals will be displayed. 80/40/20
signal conditions are such that anything more than 40 to 45 dB of range
is far too much. You can see the effect of these controls better in the
fast fourier transform "Spectrum" display mode. Adjust the "Ref"
control so that the max signal you are receiving is about 2/3 scale.
The adjust the "Amp" control so that the noise level is just barely
visible at the bottom. Go back to the waterfall and fine tune the
controls to give a range of colors to your liking. These controls
change very rapidly if you hold the mouse button down (default in gtk,
the toolkit used for building the gui stuff). So I recommend just
single clicking the up/down buttons.