PompeyPaul
You are heading 280 with the NDB on a
relative bearing of 160 - so the beacon is located 20deg to starboard of directly aft of you (100), i.e. 080.
The tail of the ADF needle (indicating your bearing FROM the beacon) is thus pointing 20 deg left of the nose, i.e. 260.
NDBs read Mag, so subtract the 5 deg variation to convert to True = 255.
I think that's it...
Gadget 