This circuit uses a feedback integrator. We found it in Ferranti's transistor manual from 1974. Transistors are general-purpose types at the time.
This TTL circuit was found in the December 1990 issue of Radio Electronics magazine. The circuit has...
Found in an Electronics World of 1968 this circuit can use any SCR and diodes depending on the...
Placed near a telegraphic transmitter (CW) and with a small antenna or pickup, it reproduces the...