This circuit generates a siren sound. It was found in the April 1969 Radio Electronics magazine. The output signal is to be applied to an external amplifier.
This configuration is from an old Motorola documentation from the 70s. The circuit uses operations that...
This circuit with transistors of the time was found in the November 1972 Radio Electronics...
This simple multitester tests continuity, semiconductors, leaks, and other common component...