Many important applications of single channel per carrier (SCPC) operation involve communication links between earth terminals whose

values differ substantially. Typical links might connect a small community with the closest commercial center, or an offshore oil rig with a base station. In order to make the best use of the available satellite power, the levels of the carriers directed to the two earth terminals are adjusted in accordance with the respective

values. This paper extends results previously derived for the equal carrier case[1] and provides closed-form solutions for optimum transponder backoff and transponder capacity in terms of the link parameters for the case of two unequal carrier levels.