The transistors of this circuit found in an English 1980s documentation may be the modern BC548 equivalents. The circuit is battery powered and the earphone must be crystal.
This circuit is na analog display of LEDs, operating from a voltage signal applied to mits input....
August 2017 - Texas Instruments is announcing the availability by Mouser Electronics of its new...
This is a conventional double T oscillator, where the frequency is determined by the double T...