Abstract: These and other objects of the present invention are provided by an ambient load waveguide switch mounted between a feed horn and a low noise amplifier in a ground based antenna. The ambient load waveguide switch includes a housing assembly having a through path. A shuttle assembly is positioned within the housing assembly and moves linearly within the housing assembly on a guide assembly between a first position and a second position. In the first position, the shuttle assembly has a waveguide alignable with the through path of the housing assembly. In a second position, the shuttle assembly has an ambient load element alignable with the through path of the housing assembly. A motor assembly moves the shuttle assembly in a first direction and compresses a first spring to bias the shuttle assembly into the first position. The motor assembly moves the shuttle assembly in a second direction and compresses a second spring to bias the shuttle assembly into the second position.