This simple radio was found in a Popular Electronics from the 90s. L1 and L2 have 100 turns on a toroidal core and L1 have a socket on the thirtieth turn.
This circuit from a 2003 documentation, has a protection system that disarms the power supply if...
This circuit was obtained from an old American documentation, and practically any general-purpose transistor...
In the figure we have the circuit of a sweep generator obtained in an old publication. The central...