Abstract: A sliding load for calibrating a microwave network analyzer provides an alignment of its center conductor relative to a reference plane defined by its outer conductor. The sliding load includes a latching assembly which in an unlatched condition allows the center conductor to move freely in an axial direction relative to the outer conductor. The center conductor can then project forward of the outer conductor for visual alignment with a mating center conductor of a network analyzer connector. Once the center conductors are mated, the outer conductor of the sliding load and the connector can be butted at the reference plane. The latching assembly can then be rotated into its latched condition in which a spring is compressed. The compressed spring forces the center conductor to retract against a screw stop. The screw stop is adjusted so that when the center conductor is forced against it, the desired alignment of the center conductor and the reference plate is achieved.