CRT Receivers for Mechanical Transmissions

As early as the late 20s, experimentation was going on with the use of cathode ray tubes to display television images. Philo Farnsworth displayed a crude image in 1927, and Max Dieckerman did the same in 1928. By 1929 Vladimir Zwoykin, then with Westinghouse, was experimenting with CRT receivers. In the early 30s there were many CRT receiver designs.

1931 Circuit diagram of a CRT receiver