Abstract
Nuclear radiofrequency absorption can be observed by means of a super‐regenerative detector. The sample is placed in the coil of the resonant circuit, and reacts to produce an observable signal by nuclear absorption when the external magnetic field is such as to produce a Larmor precession at the same frequency as that of the super‐regenerative detector. An autodyne detector, oscillating weakly, can also be used to observe nuclear resonance absorption.