Found in Popular Electronics, this sophisticated short-wave receiver requires a lot of skill from an eventual assembler. The coils are commercial types of the time, used in commercial radios.
The circuit shown in the figure generates a rectangular signal whose frequency depends on C1. For...
Using a 12 V transformer, this unit can provide a much higher output voltage. The circuit is from a 90’s...
This circuit is from a technical documentation from the 70s, and equivalents can be used for...