Electronic Communication Systems 2nd Edition by Roy Blake

Exercise 9

The spectrum analyzer display in Figure 3.21 represents the output of an AM transmitter. The analyzer has an input impedance of 50 and is connected to the transmitter output through a 60 dB attenuator. Sketch the envelope of the signal in the time domain, as it would appear at the transmitter output terminals. Be sure to show both time and voltage scales.
Figure 3.21

Reference level: -10 dBm
Vertical: 10 dB/division
Center frequency: 21.200 MHz
Span: 5 kHz/division