ARRL

Communications Systems

Overview

Some of the most powerful capabilities of Amateur Radio are techniques that combine appropriate modulation (analog or digital) with protocols defined by computers or other special control logic to create a system.  Some examples:

  • ALE (Automatic Link Establishment) is based on government standards for automatically connecting HF radios.  The protocol searches through available frequency bands and creates a channel that is appropriate for current band conditions.
  • APRS (Automatic Packet Reporting System) is a system that automatically transmits a GPS position or other desired data using packet relay technology to interested monitoring stations.  APRS can be extended with Internet links to provide real-time information on a local, regional, or global basis.  Click this link for further details on APRS.
  • Repeaters are automated receiver-transmitter systems that rebroadcast your signal enabling wide area coverage for even small handheld transceivers.  Sited at favorable hilltop locations, repeaters are most often used for FM voice service in the VHF and UHF bands.  Amateur Radio satellites operate special repeaters allowing contacts for thousands of miles.
  • Internet Linked Systems are local stations or repeaters that are connected through Internet "tunnels" to extend your local VHF/UHF radio communications to sites around the world. Examples are Echolink, IRLP (Internet Radio Linking Project), WIRES-II, and D-STAR.
  • Other Internet Based Systems.  Some amateurs operate remote base stations using special Internet links.  Email systems have been developed for emergency or maritime use, such as WinLink and PSKmail.

Books and Publications

Repeaters

Repeaters (Regulatory)

Internet Linked Systems

Articles

ALE

Repeaters

Web Links

ALE

Repeaters

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