We found this circuit in a 1980s American documentation. The operational amplifiers of the integrated circuit used can be common types in an experimental setup.
Found in Ferranti's 1969 documentation, this circuit can be mounted with a modern equivalent...
The circuit shown, found in a 2004 documentation, allows the use of a telephone, without the...
The circuit presented is a simple MW tuner that can be plugged into the input of any audio...