Of course, the current is extremely small, but a voltage of 300 V can be obtained from 9 V of a battery. The circuit is from an Electronics Now of May 1994. C1 adjusts the operating point.
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...