42-Channel digital pll voice transmission system, 823-832 mhz and 863-865 mhz as a tour guide system also suitable for any other application in which a two-way communication is required, e.G. Training sessions, lectures with questions and answers and grou
42-Channel digital pll voice transmission system, 823-832 mhz and 863-865 mhz as a tour guide system also suitable for any other application in which a
