Based on a set of experiments, using a transversely exited (TE) oscillator-amplifier N2-laser system (OSC-AMP) with the AMP effective length of 31cm, measurements have been carried out for small signal gain, g0, and saturation energy density, Es, for different AMP gap separations. It was found that the gain-value depends on the AMP electrode gap separation, dAMP and thereby the corresponding gain coefficient dependency on the E/p, Te, and pd values are introduced. This experiment shows that in addition to laser excitation length dependency of the gain coefficient, the electrode gap-separation is also an important factor for determining the gain-value, where in the present system it is maximized for pdAMP~55 Torr.cm. In addition, it was found that, regardless of the type of lasers, and their geometrical configurations, the measured Es-parameter is linearly related to the output energy density, E0.