Bundesanstalt für Flugsicherung, Frankfurt (BFS) / Deutsche Flugsicherung, Langen (DFS) :

BFS (federal german aviation safety office) was in charge of all aeronautical NDBs as a part of the navigation system. In 1992 BFS was privatized and named 'DFS Deutsche Flugsicherung'. BFS/DFS moved from Frankfurt/Main to Offenbach, later to Langen (all close to Frankfurt/Main, where Germany's central airport is)

 

no recordings available

see this funny letter in german, sent in 1999 to Hans-Peter Tillmann
a 'funny' letter, because the DFS is refusing to send a QSL due to legal restrictions: listening to NDBs is illegal, thus no QSLs are allowed...
if you look on this webpage for NDB-QSLs, you will find many, many QSL-cards, issued by BFS/DFS, from the 1980's until now

 

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