Found in na 1969 Electronics World, this circuit makes use of transistors of the time. Equivalent transistors can be used. The diodes can be 1N4004.
Found in Popular Electronics of January/February 1969, this transmitter has a few meters range and can...
Found in 1969 RCA documentation, this circuit maintains constant current in the filament of a lamp...
Found in a 90s 73 magazine, this circuit uses an unusual component today which is the XR2206. |...