FUJICA - Fujica STX1 Exposure Meter service

Technical service manual for the FUJICA STX-1 exposure meter system, providing workshop procedures for precision adjustment and calibration of the camera's metering circuit. This repair manual concentrates on two core adjustment protocols essential for accurate light measurement: voltage calibration of the metering electronics and meter needle positioning under controlled conditions. The voltage adjustment section (14-1) walks through disconnection of electrical connections, installation of the variable resistor assembly, potentiometer, and printed circuit board components with exact target specifications. Technicians will reference 437±2 mV across terminals A and F of the variable resistor assembly and 380±2 mV across terminals B and D of the circuit board during calibration. The meter needle adjustment section (14-2) includes practical testing procedures across the full luminosity range from LV7 (low) to LV14 (high), using standardized camera settings: ASA 100 film speed, 1:2.2 lens at 55 mm, 1/60 second shutter speed, and 710 lux reference illumination. Ambient temperature is held at 22±5°C for measurement accuracy. Detailed electrical schematic diagrams (Figures 53 and 54) map component positions and identify the three adjustment potentiometers (VR1, VR2, VR3) on both the variable resistor assembly and main board, allowing precise calibration without guesswork.