Call Signs of Amateur Radio Stations

The FCC assigns call signs to amateur radio stations. FCC regulations require that amateur stations identify themselves at the end of each conversation, and if a conversation lasts longer than 10 minutes, the hams are to give their call signs every 10 minutes. This regulation applies to amateur stations operating in emergency situations as well as in normal conditions. It is not necessary or desirable for stations to identify themselves at the end of each transmission if the transmissions are short (typically, a few seconds). A sequence of short transmissions is considered as one conversation. In addition, hams give their call signs when they first check into a net. The time that a station is checked into a net is considered as one conversation. Hams checked into a net do not need to give their call signs when they leave the net.

Real Call Signs

During net operation in an emergency, it is customary when no traffic is being sent but the net has not been closed for the NCS to keep track of the time and to identify itself every 10 minutes. When members of a net hear the NCS give its call sign, they can heed that cue and give their call signs. If the NCS forgets to identify itself, any member of the net can identify itself as a cue for the NCS and other members of the net to follow suit. I've heard this procedure occur during small nets, but I haven't heard it happen during large nets. So, follow the procedure established by the net Managers of the nets you associate with.

Tactical Call Signs

When providing temporary communications in an emergency, the NCS needs to know two things about each station in the net: the call sign used to contact each station, and the location of each station. If real call signs are used during the net, the NCS will need to keep a correlation sheet giving the real call and the location of each station. However, if tactical call signs are used, the tactical call signs can be created such that they identify the locations of the stations, thus avoiding the need for the NCS to use correlation information when assigning traffic to or from members of the net. For example, suppose hams are providing communications for an ambulance service. The NCS might invent tactical call signs as follows: Base, hospital, triage, ambulance1, ambulance2, etc. The NCS in opening the net will state that tactical call signs are to be used, and when individual hams are assigned to particular locations, they are told what tactical call signs to use.