We found this circuit in a 1964 Electronic Design. Transistors can be modern general-purpose equivalents. The circuit converts a 1 MHz sinusoidal signal into a rectangular signal.
This circuit was obtained from a 1985 Electronic Desing. The circuit uses a Darlington which may be...
This high selectivity circuit for single tone decoding was found in 1970s documentation. The coil...
This circuit for analogue TV was found in an American 1980s documentation. The transistor can be any RF...