Figure 1: Principle of an Robinson Scanner.
Robinson-Scanner is an electrical scanning feed for height-finders. It has an organ-pipe switch, which is connected to a number of single feeds in a very wide common horn. For a phase-correct connection, the lengths of all waveguides between the organ-pipe switch and the feeds must be of the same length. The motor rotates the switch with about 20 rpm and the beam scans from minimum elevation angle to maximum. The antenna pattern may nodding very fast but the reflector stands still.
Picture gallery of Robinson Scanner
Figure 2: Heightfinder AN/SPS-8 using a Robinson Scanner.
- Charles V. Robinson Full Reverse Roll Throat Scan Horn. U.S. Patent 2,761,136. Patented Aug. 28, 1956. (Google Patents)