This 1960s Japanese 5-transistor radio is powered by 9 V and has good sensitivity for the medium wave range. The configuration is of the superheterodyne type with FI 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...