This circuit was found in a Signetics documentation from the 1980s. The integrated is a PLL and the SCR is a general purpose type The pitch frequency is given by R1 and C1 as formula next to the diagram.
Short pulses can be found in this 90's EDN circuit. The load is 50 ohms and the transistors are from that...
Found in an American 1980s documentation, this circuit generates frequencies in the range...
This old configuration of an audio amplifier has a push-pull two-transistor output stage. Output...