Found in a 1967 EEE, this circuit oscillates at 20 MHz according to the values of the given components. The FET can be of general use. The coil has only indicated the number of turns.
Yes, tunnel diodes can also be used in voltage regulators, as shown in this circuit from a Radio...
The gain of this circuit at 1 kHz [and 40 dB falling rapidly when the frequency deviates from this...
A frequency of up to a few kilohertz can be obtained with this oscillator. The frequency is given...