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.
This configuration, which does not have a very high Q, uses a 741 operational amplifier, but other...
This circuit generates low-frequency sinusoidal signals. The variable capacitor is dual and the...
This circuit was found in a documentation of the year 1958. The transistors are germanium types...