This commercial radio for the AM band was sold in Japan in the 1960s. The circuit has an IF of 455 kHz and is powered by batteries. The push-pull output gives a good audio power.
The transistor can be the BD135 and this circuit, found in a 1978 publication, can be powered by...
This interesting circuit measures the distortion of the sinusoidal voltage of the power grid. We...
This sophisticated circuit is from a 1975 documentation. The components are from the time and the...