We find this oscillator in a 1980s documentation. The frequency depends on the crystal and the transistor used must be able to oscillate at the desired frequency.
This simple experimental circuit using only transistor produces a tone given by C1 and C2. Tone is...
This power supply may have 5, 6, 9 or 12 V outputs depending on the 78XX and 79XX series...
This circuit is from Philips' 60s documentation. The circuit can be applied to modern operational...