This old fashioned transistor amplifier was found in a publication of the year 1958. Transformer are the critical components in the circuit and power comes from 6 D cells.
With this circuit, obtained from an American publication for radio amateurs in 1976, it is...
Small variations in the resistance of the skin of a person holding the electrodes can be detected by...
This circuit was found in a 1967 American documentation. The circuit uses components of the time,...