This reinforcing stages from a 1960s documentation. No information is given about the transformer and the transistor admits equivalents.
This 1.5 A source for FM transmitters was originally intended for the transmitter described in...
This metronome configuration with the 555, quite common was found in a 90s Hands On Electronics. The...
This circuit was found in a 1958’s publication. It uses germanium transistor, availble that time....