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This audio filter was found in the August 1993 issue of Radio Electronics magazine. It cuts low and high frequencies corresponding to rumble and scratch noises that occur on turntables.
This aperiodic circuit was found in an old English documentation. The transistor can be any JFET...
This FM transmitter circuit was found in a Japanese publication in 1975. Equivalent transistors can be...
This circuit can oscillate at frequencies up to a few tens of megahertz depending on the crystal. The...