With all utensils made in China we have successfully manufactured a broadband Er 3+ doped fiber superfluorescence source. The basic characteristics of the superfluorescence source, such as the output power, output linewidth, and the change of the linewidth with temperature, have been analyzed and studied. And rather good experimental results have been obtained. To address directly the question why the natural fluorescence spectrum of the broadband source has a pinnacle structure which results in a too narrow linewidth, we present a simple but effective measure to restrain the pinnacle. Consequently, a spreaded frequency spectrum with a satisfactory width has been obtained.