This Wien bridge oscillator circuit uses a Texas Instruments 709 amplifier. It was found in an article in the September 1972 issue of Radio Electronics magazine. It is powered by a 24 V voltage.
This powerful source was obtained in an American documentation of the 80s. Some components are...
This simple transistor tester was found in a Japanese magazine in 1967. It tests general purpose...
This transistorized astable for LEDs was found in the January 1992 issue of Radio Electronics...