Found in a 1924 publication, this 2-valve receiver has a speaker output. Power comes from several batteries. Information about the coils is given.
This tone-modulated transmitter was found in recent English documentation. The circuit operates in the 27...
This simple CMOS digital game was found in an English publication in 1992. The circuit uses a...
This good quality stereo amplifier was found in a Japanese publication from the 1960s. The circuit...