NavList:

Let’s not forget the Zeppelins.  The military Zeppelins navigated with varying degrees of success with both ground based DF bearings transmitted back by WT to the calling Zeppelin and with the Telefunken Kompass Sender System, 1908-1918, so it would be reasonable to assume they picked up again with their first civil passenger carrying Zeppelin, the LZ127 Graf Zeppelin in 1928, especially as the ship had a radio room, a selection of receivers and transmitters, and three Radio Operators!  Apparently the ship had a maritime style loop DF aerial under the gondola.  An artists impression of it can be viewed here http://www.seefunknetz.de/lzzep.htm (fourth picture down).  German speakers, not me, will be able to read about it in detail. DaveP