The binary phase complementary code set has been used in stratospheric radar sounding. The quasi‐complementary code technique presented here has nearly complementary properties and offers significant reduction of side lobes caused by imperfections in the radar transmitter. The new technique and its application are described; a simulation of the performance of the two techniques when certain imperfections are present in the transmitter is presented. The results are compared with the actual performance of the Arecibo 430‐MHz radar transmitter. Copyright 1984 by the American Geophysical Union.