This circuit for a frequency of 40 kHz was found in an old Electronic Design. There were no constructive data for the transformer used in the output.
This old amplifier, with germanium transistors, was found in a Japanese technical magazine in...
This is the well-known lightning lamp that was published in the March 1988 issue of Saber...
This VFO was found in a 1980s documentation. The central frequency is given by the crystal and the...