This report contains a study for implementing an eight phase directional cylindrical antenna for the tactical communication system ERITAC. The report describes ideas for implementing control of the directional cylindrical antenna. It describes problematic issues and gives solutions to them. The report describes a tested prototype solution. It describes that changes made on the ECCM unit and the PRO unit are all made in software. It describes a possible design solution of a new unit to control the antenna switch. This unit is called the antenna switch control unit and is supplied and controlled from the Radio relay unit. The system is designed to function in the master station in Point to multipoint communication. But solutions are also given for the cylindrical antenna to function in point to point communication and on the out-stations in point to multipoint communication mode. Testing and evaluation of the system have shown that the antenna lectronics select the right direction and that the time delay for the electronics is around 120 microseconds. This gives a good margin for the time delay for the antenna switch and the synchronization of transmitting and receiving when the available change interval is 1.125 milliseconds. The report also mentions ideas that have been discussed but abandoned for some reason.