For radio during the Nazi Era:
The SWR (Südwestdeutscher Rundunk, Southwest German Radio) has a set of complete radio broadcasts:
https://www.swr.de/swr2/wissen/archi...-1933-100.html
Some of the examples are from the BBC, though
Post War:
You might want to look for "Nordwestdeutscher Rundfunk", which was established in December 1945 and split into two broadcast services in the early 1950s