Remove the Diode Detector and Resistive Terminator and connect the components as shown in fig 1.4, ensuring that the probe of the Slotted-line Detector is projecting no more then about of the slotted line. Connect its waveguide assembly where the Diode Detector was, and add a blanking plate to short-circuit the microwave.
Adjust the depth of penetration of the probe into the slotted - line at both attenuators to obtain full - scale deflection (fsd).
Use the Slotted - line Detector to find two successive positions at which the signal reaches a sharp null. Note each position carefully against the scale on the waveguide.
These nulls arise because the signal from the microwave oscillator travels along the guide to the short - circuited end. Its energy cannot be absorbed by the short - circuit, so the signal is reflected back.