Complex sentence: In the dynatron and transitron circuits, a vacuum tube is biased so that one of the electrodes has negative differential resistance to the cathode, and a parallel tuned circuit is connected between the electrode and the cathode.
Split into simpler sentences: In the dynatron and transitron circuits, a vacuum tube is biased so that one of the electrodes has negative differential resistance. A parallel tuned circuit is connected between the electrode and the cathode.