This dual balanced modulator configuration was obtained in a 1980s telecommunications documentation. The circuit makes use of transformers and the diodes are commonly used.
This simple intercom for home use was found in a 1979 publication. It can be easily mounted with...
This circuit was obtained from American documentation from the 1990s. The transformer can be a car...
This wired intercom circuit was found in an English publication from the 80's. The integrated...