ADX cluster is anetwork of computers, each running asoftware package dedicated to gathering, and disseminating, information onamateur radioDX (long-distance contact) activities.
The computers comprising the network are callednodes, the network itself being termed acluster of nodes. The nodes may be connected either viaradio links or through theinternet. Internet nodes generally connect using thetelnetprotocol.
The system acts as an aggregator of information, accepting input from various sources, then making that data available to any user who is connected to the network.
The first DX cluster software, PacketCluster[1] was realized by US radio amateur Dick Newell, AK1A in the late 1980s, and quickly became popular as a means of exchanging DX-related information. Before the internet became widely available, the nodes running the cluster software would connect viaradio links at certainfrequencies allocated within theamateur radio bands. Users of the system would then connect to a node using frequencies different from those used by the nodes.
When the internet became widely available, the system was expanded to make use of telnet connections to internet nodes, in addition to the already established packet radio nodes. Users of internet nodes connect to a particular node usingtelnet client software.
A number of DX cluster software packages are available, among which are: