This circuit was found in American documentation from the 90's. The transformer determines the output voltage. The transistor must be equipped with a heat sink.
This different astable configuration was found in one in a 1974 Ferranti transistor manual....
Alorium Tech XLR8 Application Accelerator & Development Board is an Arduino-compatible board that...
This filter is from the Linear Applications Handbook of the National Semiconductor of 1994....