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.
Found in a November 1977 Radio Electronics magazine, this digital circuit was described in an...
This powerful transmitter for the 27 MHz band was found in a Japanese publication from 1961. The...
This circuit was found in Radio Electronics magazine from April 1961. The device has a slot for...