Hitlerjugend: An In-Depth History: HJ-Signal
by Arvo L. Vercamer

This group focused its activities on teaching its members specialized military communications skills. It was separate from the HJ-Nachrichten group. Its members had to be proficient in Morse code signalling and in wireless communications skills. By 1943, the Signal-HJ was absorbed by both the Flieger-HJ and the Luftwaffenhelfers and it essentially ceased to function as a separate entity.