This paper aims to analyse the performance of coded frequency hopping /spread spectrum mul~ tiple access system by employing the channel with mixture of A WGN, partial band jamming, fading and user interference. In this approach, a special consideration is focused on the effect of the partial hit. That is, the interfering signals that are present for a small fraction of the hop dur~ ation did not cause hit. The results of analysis showed that the frequency hit changed linearly according to the varying degree of frequency overlap. And this effect did not change the type of error probability distri~ bution.