The following people and organizations have supplied pictures and information about communication equipment:

            Karl-Heinz Allermann, DK6AL (ALGRA Funkarchiv)
            Per-Tore Aasestrand, LA7NO
            Meir Ben-Dror, WF2U
            Josef Bungartz, DG2KCL
            Heinrich Busch
            Ulrich Frankhäuser
            Walt Novinger
            Christof Proft
            Bernd Reckling, DC7FQ
            Klaus Richter
            Siemens Archiv München
Many thanks to all of them.

We must apologize in advance if we have forgotten to mention somebody who has contributed as well.