Radio broadcasting was probably the most dynamic technical mass medium of the Weimar Republic. Within just a few years it established a powerful institution and an immaterial network. With ist ›wireless waves‹ the radio transformed virtually the whole territory of the German Reich into a centralist controllable sphere of sounds. Nevertheless, it reached its limits in 1928. Newer, even more suggestive media emerged or cast their shadows: sound film and television. At the same time, German broadcasting came under attack due to its limited amplitude, its lifeless programs and its rigid censorship. This article shows how the radio in the midst of debates on media represented the basis for fantasies about media and how, simultaneously, its definite transformation was demanded.