Using the Voyager 1 and 2 (V1 and V2) planetary radio astronomy experiment, we have analyzed the data in the kilometric wavelength range from January to December 1979, the period which includes the Jupiter encounters for V1 and V2. Statistical studies of the broadband kilometric radiation (bKOM) reveal new results on the polarization and beaming of the emission. The northern and southern components are right-hand and left-hand, respectively polarized, without reversal at encounter. The central meridian longitude occurrence of these two components is dependent on the zenographic latitude of the observer. The shadowing by the Io plasma torus is confirmed, the boundaries of the emission beam have been deduced, and it is shown that the latitudinal beaming of the emission is dependent on local time, from dayside to nightside observations. Our results are discussed in terms of a source radiating in the extraordinary mode. It is suggested that the source regions are at the inner boundary of the Io torus all around the planet and that the emission is beamed into a hollow conical sheet whose axis coincides with the magnetic dipole of the planet. Radiation mechanisms are briefly discussed; the maser synchrotron instability and the non linear conversion of electrostatic waves could contribute to bKOM, each one in a limited frequency range.