This circuit was found in a Popular Electronics from the 90s. The components admit equivalents and the phototransistor can be of any type.
This 1980s circuit was found in Motorola documentation. The circuit uses period components that admit of...
The author of this project found in a 1980 documentation gives the radio in two versions: the...
Using a 741 operational amplifier, this circuit amplifies very low voltages, allowing its...