DF Loop Antenna - all infos

[Delfi]

Originally Posted by gambla

you're confusing it with the smaller but also rotating KDB, which was mounted on top of the bow:

"The KDB (Crystal Rotating Base Apparatus) was an improvement of the GHG in that it was rotatable and hence able to provide more accurate readings from any direction. The disadvantage however was its extreme vulnerability to depth charges."

example picture from Wikipedia: https://upload.wikimedia.org/wikiped...hydrophone.JPG

That explains why the German boats can't hear anything while on the surface.