This very low frequency circuit was found in a 1964 Electronic Design. Transistors may be modern equivalents. The filter is low pass type.
This circuit is from a 1968 publication. It uses germanium transistors from the time, having...
This circuit can be used as shield or to drive powerful loads from low current switches such as...
This is a 6-transistor transistor receiver manufactured in the 60s. The circuit is a...