This excellent tube preamplifier was found in Radio Electronics magazine from July 1958. The power supply was not included. The circuit has several inputs.
This circuit using only transistors was obtained from Ferranti's 1969 documentation. It can be...
This sensitive circuit can be designed with FETs such as BF245 and MPF102. The sensor is a silicon...
Found in Popular Electronics from the 90s, this circuit generates two tones that are selected by a...