RSM Vol 20 - How To Find The Defective Part With A Voltmeter

This 1947 educational manual from the National Radio Institute instructs technicians on using a voltmeter to diagnose and repair radio equipment. The text begins by explaining voltmeter characteristics, such as how sensitivity and internal resistance can influence the accuracy of a reading. It details practical servicing methods for identifying malfunctions by comparing measured supply voltages against manufacturer specifications. Through the application of Ohm’s Law and Kirchhoff’s Voltage Law, the guide demonstrates how to interpret fluctuating, low, or high voltage levels to find defective components. Detailed schematic diagrams and troubleshooting tables further illustrate how to test various circuits, including power supplies and amplifier stages. Ultimately, the source serves as a technical foundation for mastering radio maintenance through precise electronic measurement.