Abstract: An angularly adjustable coupler is provided having first and second ends that are in an angularly adjustable mating engagement. The first end has a longitudinal axis and a base with an optionally concave and serrated surface, and can comprise a collared clamp for connecting to a pylon. The second end has a longitudinal axis and a base with an optionally convex and serrated surface, and can comprise a receiver for connecting to a pyramidal adapter. The concave portion of the first end and the convex portion of the second end are complementary to each other. A connector is provided to connect the first and second ends in a selected angular alignment about a fixed axis of rotation. The range of angular alignment of the first and second components spans approximately 50 degrees about the fixed axis of rotation.