PENTAX - Pentax spotmatic k1000 Meter substitution

This PENTAX technical service bulletin provides comprehensive instructions for retrofitting a K1000 meter into Spotmatic SP series cameras. The document establishes critical physical differences between the two meter assemblies with comparative diagrams detailing dimensional variations (10.2 mm for SP type versus 11.8 mm for K1000) that directly affect fit and function. The modification procedure walks technicians through precise steps: trimming the plastic meter body ends to specification, removing the bottom cover plate, and applying insulation tape strategically to prevent electrical shorts between the meter assembly and camera body. The installation section explains positioning in detail—the K1000 meter mounts centrally while the original SP meter sat off-center, a critical distinction affecting both mechanical clearance and electrical routing. Separate procedures address the required 2µA current application with two alternative methods suited to different test equipment configurations. The wiring section covers the cutting and soldering sequence necessary after meter installation to maintain proper circuit continuity. Throughout, the bulletin alerts technicians to operational behavior changes: the meter's off position shifts slightly and sensitivity drops marginally compared to the original unit. Clear mechanical diagrams, current test schematics, and wiring distribution illustrations support each procedural step to ensure accurate installation and reliable long-term operation.