[Sir Tex]

Hi,
can anybody help me? I'm trying to find out which Luftwaffe Battalion is mentioned on the back of a postcard but i can't quite make it out. I think its a construction battalion ("17") but i'm not sure. The officer on the front is a certain Hauptmann Krause and the location is apparently "Reichenau" but there are approx. 20 places in Europe called Reichenau - most of them in Germany and Austria.
any help would be much appreciated!
Sir Tex