The German 6 th Army (with Axis forces) was surrounded at Stalingrad late November of 1942, and surrendered on 31 January 1943. It is sometimes suggested that the Feld-Hell was used as a "last resort" means of communication with the outside world. However, an estimated 90% of communication in and out of Stalingrad was done via Morse code telegraphy, and the rest via land-lines and UHF .