Veteran Bring Back German WWII Qualified NCO Directional Radio Signal Finder Trade Patches-The RDF operator would first tune the receiver to the correct frequency, then manually turn the loop, either listening or watching an S meter to determine the direction of the wave. This patch badge consists of a Luftwaffe blue-gray wool base with a machine embroidered, stylized arrows symbolizing radio waves, this sits above a “P” in a gothic script. These are good only, each has moth bites. Yours will be as good if not better than the one in the photo. We were lucky enough to purchase this directly from the family of the US veteran who brought this home, we will supply the name of this soldier to the buyer.