Rating of tubes, [235]
Reception, essential operations in, [235]
Regenerative circuit, [176];
frequency of, [179]
Repeater stations, [261]
Resistance, measurement of, [64];
non-inductive, [103];
square, [251]
Resonance, [161]
Resonance curve, [117]
Retard coils, [210]
Salt, atomic construction of, [17];
crystal structure, [147];
molecule in solution, [19];
percentage in sea water, [11]
Saturation, [38]