This image was acquired from
wikimedia. It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
Keywords from Image Description:
Tuned radio frequency TRF receiver block diagram .svg tuned radio frequency TRF receiver type of radio receiver circuit invented in by Ernst Alexanderson and widely used in the vacuum tube receivers of the It consisted of one or more tuned RF amplifiers each consisting of tuned circuit which functioned as bandpass filter followed