A nomogram, giving quickly the position and the amplitude of the side lobes of broadside linear arrays of isotropic radiators fed in phase at equal power, has been used for the preliminary design of arrays whose spacings are always larger than

and whose first side lobes are as small as possible. The equations giving the amplitude of the side lobes for sources with cosine directivity at any spacings are written and have been solved with the aid of a computer. By applying a relaxation method, it has been possible to obtain linear arrays with unequal spacings whose side lobes grow with angle of emission from very low levels to acceptable values. Tables give the spacings of the radiators, the positions and the levels of all side lobes for symmetrical arrays of 4 to 16 sources and apertures ranging from 2.47 to

.