Observation of a particle absorption microsignature of the Jovian satellite Amalthea during the Pioneer 11 close flyby of Jupiter on December 3, 1974, has been described by McKibben et al. [1983>. The microsignature was also observed by the University of Iowa/Pioneer 11 instrument in the distribution of protons in the kinetic energy range 0.61p<3.41 MeV but has not been previously reported. The finer time resolution and superior data quality of the latter observations provide a fresh basis for assessing the accuracy with which various published magnetic field models of Jupiter's magnetic field models describe Jupiter's magnetic field for radial distances of the order of or less than several planetary radii. The expected time of occurrence of the minimum of Amalthea's microsignature was calculated for each model and compared to the time of the observed minimum. The discrepancy between these two times was significant for each of the published models, but it could be reduced to zero by interpolating between two of the closely related models. The spherical harmonic coefficients of this combination model are tabulated. Also included is a novel method for calculating the intensity-time profile of the microsignature. In a later paper, the improved model is utilized to analyze the energetic particle measurements in Jupiter's innermost magnetosphere by the Galileo entry probe in December 1995 [Fischer et al., 1996>. ¿ 1998 American Geophysical Union