We report on a measurement of the angular power spectrum of the anisotropy in the Cosmic Microwave Background. The anisotropy is measured in 23 different multipole bands from l = 54 (approx. 3 deg.) to l = 404 (approx. 0.45 deg.) and in 6 frequency bands from 26 GHz to 46 GHz over three observing seasons. The measurements are consistent from year to year. The frequency spectral index of the fluctuations (measured at low l) is consistent with that of the CMB and inconsistent with either dust or Galactic free-free emission. Furthermore, the observations of the MSAM1-92 experiment are repeated and confirmed. The angular spectrum shows a distinct rise from delta Tau(sub l) is identical to the square root of l(2l1) (the absolute value of (a(sup m)(sub l))(exp 2))/ 4pi = 49(sup 8)(sub -5) mu Kappa at l = 87 to delta Tau(sub l) = 85(sup 10)(sub -8) mu Kappa at l = 237. These values do not include an overall =/- 14 (1 sigma) calibration uncertainty. The analysis and possible systematic errors are discussed.