We found this circuit in a Radio Electronics from December 1963. The circuit combines valves and transistors and has a high input resistance. The circuit is powered by two batteries.
This preamplifier appears elsewhere in this section and this version was found in American...
This 2000 circuit, found in the documentation of the time, is intended for charging this type of...
Based on the well-known LM3909, this LED pulser circuit was found in American documentation from...