Dimensions of the commercial rectangular WR650 feed I purchased off ebay Dec 2025 are 164mm wide x 82mm high x 128mm deep, with monopole probe located 57mm from back plane. Post navigation Video recording from BAA Hydrogen Line Radio Astronomy Sub-Group Meeting 5 January 2026 Shaik Samad Pasha’s dimensions for his hydrogen line horn antenna used in his CHART-21 project.
