Abstract :
In the early 1920s quartz as a frequency controlling device was slowly becoming more and more important. Already in the mid twenties the Germans relied on quartz, mainly as a secondary standard. Although Hans Vogt invented low-loss HF iron dust-core material in 1928, causing a tremendous improvement in German electronic circuit design, no other country in the world used this basic material so extensively up until 1945. From the mid thirties onwards, an extensive programme of iron dust-core products became available to the electronic industry, from small HF and IF transformers up to the medium power transmitter variometer, as well as many other applications. The second approach to a totally new equipment-design also originated at the end of the twenties and the beginning of the thirties. In this approach die-casting was used in commercial electronic artifacts, mainly for the housing and sometimes integrated with the chassis too
