This is the 1968 MR480 commercial cassette recorder circuit. The circuit was fully transistorized and powered by 4 large batteries. We found the diagram in a Japanese documentation of the time.
Only the right combination of the positions of the 6 rotary switches of 1 pole x 10 positions of...
We found this circuit in a 1977 Radio Handbook. The lamp is the critical component, being 120MB at the...
This 1964 Electronic Design circuit uses a photo-FET as a sensor. The component is rare today. |...