This article deals with the relatively late introduction of entertainment radio in Germany compared to other technically advanced countries. Following current broadcasting history, the German Post Office was initially interested in the commercial use of wireless technology after the end of the First World War. Due to the success of entertainment radio in the USA and UK, there were demands from industry and radio amateurs for its opening in Germany as well, which finally happened with a delay.

Based on new archive sources, it is shown that Egbert von Lepel is one of the pioneers of early radio technology, which has not been adequately dealt with in the history of radio science. In particular, the significance of his 1907 patent of the spark-gap transmitter ("Löschfunkensender") is unknown, although it was granted as a key patent by the Imperial Patent Office in 1911. Therefore, Telefunken paid licenses to von Lepel, but this was the subject of a secret treaty of 1919.

In this article, we examined the emergence of the new broadcast medium Radio in Germany shortly after World War I which is called Rundfunk in this country and consider the early radio transmitter stations in Eberswalde and Königs Wusterhausen.

The simulation of large scale nonlinear dynamical interconnected systems is a usual task. Due to the high complexity of the considered systems, the principle of thinking in hierarchical structures is common among engineers. This contribution proposes an approach for the numerical simulation of large systems, which keeps the hierarchical system structure alive during the entire simulation and order reduction process, which results in several benefits compared with the state of the art.

This paper deals with the propagation of electromagnetic waves in cylindrical waveguides with irregularly deformed cross-sections. Waveguides are of high interest because of its practical use as a transmission medium. Schelkunoff's method, is a semi-analytical method for computing electromagnetic waves in hollow and cylindrical waveguides bounded by PEC walls. The aim of this paper is to derive the so-called GTE's for irregular deformed waveguides.