This circuit was found in a Ferranti documentation from 1969. The transistors are common types of the company at the time. Smaller equivalents may be used. The output power is of the order of 150 mW.
This stage circuitry for amplifying microphone signals makes use of germanium transistors as indicated...
This circuit was suggested by Philips in 1967 documentation. The circuit receives modulated light and has...
This circuit is from an English magazine of 1974, but can still be assembled with the replacement of...