In this circuit, which uses only diodes, we have both simultaneous functions. The diodes are general-purpose types and the resistors have typical values of 2k2.
This National Semiconductor circuit appears elsewhere on this site. The circuit must be powered by...
In this circuit the frequency is determined by the coil and the variable capacitor. Transistors like the...
This circuit is from old American documentation, but the transistor used is still very common...