Clark Machine & Welding - 13 pages w/ Survival Rail Supports, Survival Lock, Plate, Guide Block, Yoke Assembly, Gusset, Azimuth Drive Trolley Assembly, Hub, Idler Assembly, Elevation Detail, Hub Drive, Arm Jack, Pivot Arms, Sep 1961 to Dec 1961, D11-3, D11-4, D11-10, D11-11, Box: 60. Arecibo Ionospheric Observatory records, 53-7-3581. Division of Rare and Manuscript Collections. https://archives.library.cornell.edu/repositories/2/archival_objects/283918 Accessed April 10, 2026.