Custer Horn - A novel application of fiberglass structural composites

A method is presented for solving a severe corrosion problem by replacing an aluminum radar horn with one made of fiberglass reinforced plastic. The original horn was made of aluminum and aluminum honeycomb panels screwed together. Key design and manufacturing problems engendered by the conversion from metal to fiberglass and by the requirement for mechanical and electrical interchangability are presented. Solutions discussed include: achievement of an accurately formed, interior conductive surface; protection of the conductive surface from corrosion and delamination; conductivity-heat dissipation-weight-delamination resistance trade offs in conductive surface design; strength-stiffness-weight-thickness trade offs in side wall design; moisture drainage and pressure limitation; shock resistant anchoring of mounting brackets.