Experimental investigation of the characteristics of the ammonia maser is given and compared with theory. Observed saturation characteristics agree fairly well with the theory descibed in the previous paper. The change of oscillation frequency shows the expected increase with focuser voltage which arises from unresolved hyperfine structure of the 3,3 line. Small discrepancies are explained by the velocity distribution and different saturation of each hyperfine component. Frequency pulling due to cavity detuning was measured in detail and compared with theory. Thus the velocity spread of the effective molecules in the cavity can be estimated as roughly ±30%. Tentative estimate of the center frequency on U T 2 is compared with other measurements.