An orthomode transducer (OMT) operable in a broadband (e.g. >30%), including a frequency above ˜30 GHz, with an isolation better than −50 dB, cross-polarizations better than −40 dB, an insertion loss between −0.1 and −0.3 dB for both polarizations, and return losses better than −25 dB can be produced substantially or entirely from CNC machining, comprises a turnstile for coupling a polarization diplexed waveguide with four waveguide paths; and two E-plane Y junctions each for coupling initially oppositely directed pairs of the waveguide paths such that each waveguide path has a same electrical length from the turnstile to the E-plane Y junctions as the waveguide path with which it is paired, such that the OMT is formed in 3-6 blocks, including a single block having a substantially planar mating surface that includes the matching feature, and defines one side of initial segments of the four waveguide paths. Reproducibility of these OMTs has been shown.