This astable multivibrator was obtained from a Mullard documentation from 1960. The components depend on the used transistor and on the frequency, as shown in the table next to the diagram.
This circuit was published in a 1979 magazine, but it can still be easily assembled as the...
The integrated circuit of this amplifier is not very common today. The output transistors can be...
Found in an old documentation about neon lamps, this circuit has the frequency basically...