An improved Pound‐Knight‐Watkins nuclear magnetic resonance spectrometer is described. The improved spectrometer has an arrangement which reduces frequency fluctuations by a factor of 5–10 at 30 Mc. The spectrometer is capable of stable operation, with sensitive metering, down to an rf level of 0.01 v across the sample coil, an improvement of almost an order of magnitude. The instrument also allows direct measurement of the derivative of &khgr;′, the real part of the susceptibility of the sample.