This Japanese transistor radio was manufactured in the 1960s in Japan. The circuit of 6 transistors is for the medium wave range and is powered by a 9 V battery.
This sensitive photo-diode circuit with output compatible with TTL logic was found in a 1972 RCA...
This circuit can send signals in both the VHF and FMN bands with a range of a few tens of meters. The...
This circuit was found in a Popular Electronics from the 80s. It is possible to control a relay...