Which of the following must be connected to an antenna analyzer when it is being used for SWR measurements?

An antenna analyzer is a self-contained diagnostic instrument that includes its own low-power RF signal generator, a frequency counter, and an SWR bridge. Because it generates its own test signal, you do not need to connect a transmitter to evaluate an antenna. To use it, you simply connect the antenna and its feed line directly to the analyzer's output port. The analyzer then sweeps the chosen frequency range to measure the impedance and standing wave ratio (SWR) of the entire antenna system. Connecting a transmitter or receiver to the analyzer is unnecessary and could even damage the sensitive measurement circuitry if a transmitter were accidentally keyed into it.