We'll begin by listening to some broadcast FM radio.
First, make sure your RTL device has started by clicking the File > Stop / Device menu item. When it is running you will see the waterfall frequency display moving at the bottom of the interface, as well as some moving waveforms in the other areas.
Signal Type
The CubicSDR software in combination with the RTL dongle can tune and demodulate different ranges and types of radio signals. For this example, we'll select Frequency Modulation Stereo (FMS) as the signal type.
Center Frequency
Next, you can tune in a station! Start by setting a center frequency for a station you like, by clicking on the numbers under the "Center Frequency" heading.
This will bring a range of frequencies into view -- approximately 3MHz at a time are available. Now, you can set a demodulator down on a range you want to tune. This is done by clicking in the waterfall display, with the cursor at the center of the frequencies you want to hear. This will usually be the orange and red display section, showing you where the strongest signal lies.
Here, the demodulator has been set at 91.499261MHz, and we have a nice strong signal. Music plays!
You can see the fine tuning section in the upper left corner gives us a zoomed in view of the demodulator. You can drag this one left and right in the waterfall section to fine tune, or grab one of the outer edges of the demodulator to change the bandwidth that is being processed. Too wide and you'll pick up unwanted signals, too narrow and you'll start to cut off important parts of the signal.
You can search for other stations by scrubbing the peaks display left or right and looking for strong peaks. Set down a demodulator in the waterfall area under a strong peak to listen in.
The frequency band for FM broadcast radio is 88MHz to 108MHz.
