This is the almost finished Spectrum Analyzer running on my bench. The X and Y outputs are hooked up to Channels 1 and 2 in the scope and the scope is set to "X-Y" mode (means the X input drives the sweep and the Y input drives the vertical trace). The signal that appears in the scope is from the 10MHz crystal calibrator oscillator.
Note how I take to heart my own advice from my QRV? column in QRP Quarterly magazine ("clean workarea").