This elementary receiver with a crystal earphone was found in Japanese documentation from the 1960s. The coil has 60 + 40 turns of wire 28 to 32 in a ferrite rod.
Found in an old Radio Electronics, this circuit uses common components today. The resistors of the IC...
This circuit was published in an article in Electronics Now magazine in October 1995. The circuit...
This DC-DC converter was found in old RCA documentation. The circuit operates at 15 kHz. The...