All Transistor Equivalent Book -

Famous titles include Tower’s International Transistor Selector , the Sams Transistor Substitution Handbook , and the Philip ECG Semiconductor Master Replacement Guide .

(Adrian Michaels, Bernard Babani Publishing): A staple reference providing thousands of commercial transistor types and their potential substitutes. Towers' International Transistor Selector all transistor equivalent book

Replacements must match (e.g., NPN for NPN, or N-Channel for N-Channel). Only about 40% of transistors share the exact pinout

Only about 40% of transistors share the exact pinout. If your "all transistor equivalent book" does not explicitly list pinouts, assume they are different. Use a multimeter in diode mode to verify the base-emitter junction on the new part. This is where many digital databases fail

This is where many digital databases fail. An equivalent book provides a diagram of the pinout (E-B-C or B-C-E) for the original and the replacement . If you replace a European BC548 (C-B-E) with an American 2N3904 (E-B-C) without swapping legs, you will destroy the circuit.