A new study of the amplitude of magnetospheric chorus using 1966--1967 data from the Stanford University/Stanford Research Institute VLF receivers on Ogo 1 and Ogo 3 has provided the following results: (1) The band-limited character of magnetospheric chorus in general and the double-banding of near-equatorial chours were confirmed. Activity at frequencies outside the chorus band was usually below the noise level of the VLF receiver, often more than 40 dB below peak chorus amplitudes. (2) Peak intensities typically ranged from 1 to 100 pT (m&ggr;); power spectral densities from 10-28 to 10-22 T2/Hz were observed. (3) Chorus amplitude tended to be inversely correlated with frequency, implying lower intensities at lower L values. (4) Individual chorus emissions often showed a characteristic amplitude variation, with rise times of 10 to 300 ms, a short duration at peak amplitude, and decay times of 100 to 3000 ms. (5) Growth was often approximately exponential, with rates from 200 to nearly 2000 dB/s. (6) Rate of change of frequency was found in many cases to be independent of emission amplitude, in agreement with the cyclotron feedback theory of chorus (Helliwell, 1967, 1970). (7) In spite of the relatively high sensitivity of the magnetic detectors employed in these observations, a major part of the electromagnetic spectrum at VLF in the outer magnetosphere was below the instrumental noise level; further space observations at VLF using magnetic detectors of greatly increased sensitivity are therefore desirable.