A DX cluster is a

network Network, networking and networked may refer to: Science and technology * Network theory, the study of graphs as a representation of relations between discrete objects * Network science, an academic field that studies complex networks Mathematics ...

of computers, each running a

software Software is a set of computer programs and associated software documentation, documentation and data (computing), data. This is in contrast to Computer hardware, hardware, from which the system is built and which actually performs the work. ...

package dedicated to gathering, and disseminating, information on

amateur radio Amateur radio, also known as ham radio, is the use of the radio frequency spectrum for purposes of non-commercial exchange of messages, wireless experimentation, self-training, private recreation, radiosport, contesting, and emergency communi ...

DX (long-distance contact) activities. The computers comprising the network are called

nodes In general, a node is a localized swelling (a "knot") or a point of intersection (a vertex). Node may refer to: In mathematics *Vertex (graph theory), a vertex in a mathematical graph *Vertex (geometry), a point where two or more curves, lines, ...

, the network itself being termed a

cluster may refer to: Science and technology Astronomy * Cluster (spacecraft), constellation of four European Space Agency spacecraft * Asteroid cluster, a small asteroid family * Cluster II (spacecraft), a European Space Agency mission to study th ...

of nodes. The nodes may be connected either via

radio Radio is the technology of signaling and communicating using radio waves. Radio waves are electromagnetic waves of frequency between 30 hertz (Hz) and 300 gigahertz (GHz). They are generated by an electronic device called a transm ...

links or through the

internet The Internet (or internet) is the global system of interconnected computer networks that uses the Internet protocol suite (TCP/IP) to communicate between networks and devices. It is a ''internetworking, network of networks'' that consists ...

. Internet nodes generally connect using the

telnet Telnet is an application protocol used on the Internet or local area network to provide a bidirectional interactive text-oriented communication facility using a virtual terminal connection. User data is interspersed in-band with Telnet cont ...

protocol Protocol may refer to: Sociology and politics * Protocol (politics), a formal agreement between nation states * Protocol (diplomacy), the etiquette of diplomacy and affairs of state * Etiquette, a code of personal behavior Science and technology ...

. 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.

History

The first DX cluster software, PacketCluster 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 via

links at certain

frequencies Frequency is the number of occurrences of a repeating event per unit of time. It is also occasionally referred to as ''temporal frequency'' for clarity, and is distinct from '' angular frequency''. Frequency is measured in hertz (Hz) which is e ...

allocated within the

amateur radio bands Amateur radio frequency allocation is done by national telecommunication authorities. Globally, the International Telecommunication Union (ITU) oversees how much radio spectrum is set aside for amateur radio transmissions. Individual amateur sta ...

. 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 using telnet client software.

DX cluster software

A number of DX cluster software packages are available, among which are: * PacketCluster - the original, and still widely used, radio packet cluster software * DX Spider - the most widely used of the internet-based cluster software packages * CC Cluster * Clusse - older cluster software

References

{{reflist Amateur radio