Dimensions of two types of lower gain pyramidal horns that have approximately equal beamwidths in the principal planes using S = 0.1 approximately in the two planes.  Two designs are given because the design cannot satisfy the design values of S in the two planes and meet a 2:1 ratio waveguide in the single plane (a physical requirement for the joint to the waveguide). Download executable RHOPTG (Linux version) will design these horns in a DOS window.