This high quality circuit with complementary symmetry was found in an Electronics World of 1966. It can be made with modern transistors like the BD or TIP series.
This setting appears other times in this section from other sources. This is from an 80's American...
This digital timer provides timings from 1 minute to 10 hours with indication on a 3-digit...
Signals from 27 MHz to 150 MHz can be produced by this one-transistor oscillator. The frequency...