General exam question G4B04

WhyThe attenuated RF output of the transmitter is the signal source connected to an oscilloscope's vertical input when checking a transmitted signal's RF envelope pattern. To view the RF envelope pattern of a transmitted signal on a scope, the transmitter's own RF output, reduced to a safe level by an attenuator or sampling network, is fed into the scope's vertical input so the envelope's actual shape can be observed, answer D. The local oscillator, an external RF oscillator, or the balanced mixer output are all internal transmitter signals that don't represent the final transmitted envelope.