Umkehrwalze D: Enigma's Rewirable Reflector - Part I

Spanish Enigma: A History of the Enigma in Spain

“…However, this is one of the specially wired machines that probably were used by the German Military Attaché or the German Abwehr. 17 Wiring D (Schaltung D) is a specific German wheel wiring and it should not be confused with UKW D, Umkehrwalze (reflector) D, which has variable wiring changeable by tiny plugs; for more details see [20]. 18 The Italian Army also used Enigma machines with wiring D. It is therefore impossible to say if the Italian machines found in Spain were used by the Army or the Navy; however the majority of the users were naval.…”

“…29 The wheels have nine notches at A, C, G, I, M, P, T, V, and Y. 30 For further details about Umkehrwalze D see Philip Marks' detailed description in [20]. 31 ''Review of material relating to the K-machine plus 'D'.''…”