SPT - 1970

Technical service notes collection published by The Society of Photo-Technologists covering repair and maintenance of two precision instruments. The first section provides a detailed service manual for the PRONTOR SVS Shutter, Model 0475, including disassembly procedures, operational principles, and repair guidance. It documents actual service defects encountered in the field—specifically broken teeth on the diaphragm index ring and faulty retaining springs—along with a comprehensive mechanism description covering shutter speeds from 1 second to 1/300, diaphragm aperture settings from f/4.7 to f/45, and the self-timer system design. Disassembly and reassembly procedures are explained step-by-step with detailed technical illustrations of the hollow pinion gear system and diaphragm control mechanism. The second section addresses the KEYSTONE Model K-620 Super 8 movie camera, focusing on meter battery access, film compartment disassembly, shutter mechanism extraction, and optical assembly removal procedures. Dimensional schematics and precise instructions for proper jig usage ensure correct reassembly. This workshop manual serves camera repair technicians and cinematographic equipment specialists requiring authoritative guidance on servicing these specific models.