Found in Radio Electronics from May 1959, this transistor tester is quite sophisticated. The circuit uses a 1 mA analog indicator.
This circuit converts square (rectangular) signals into triangular signals with typical 16 V...
We found this circuit in a spy book from the 90s. Transistors admit equivalents and the coil can...
This circuit was obtained in a 1979 English magazine. This circuit is a treble filter that,...