This sensitive Japanese mid-wave receiver from the 1960s has an output power of 45 mW and is powered by 3 batteries (4.5 V). The circuit is superheterodyne with an IF of 455 kHz.
This circuit is from a documentation from the 90s. The transistor can be any general-purpose FET...
Found in an Elektor from the 90's, this double door-bell drive circuit switches a relay by...
Using a CA3130, this circuit generates signals from approximately 550 kHz to 1.6 MHz using a...