This circuit was obtained from Popular Electronics of the 1990s. The circuit uses common transistors today and the frequency is given by the crystal.
This circuit was found in an old TTL circuit manual. The circuit must be powered by 5V, and the...
This amplifier for biological research was found in an Electronic Design from 1964. The...
Found in National Semiconductor publication from the 1980s. This gain-100 circuit can be...