Terminal node controller

AEA (Advanced Electronic Applications Inc.) PK-232MBX, circa 1991

A terminal node controller (TNC) is a device used by amateur radio operators to participate in AX.25 packet radio networks. It is similar in function to the Packet Assembler/Disassemblers used on X.25 networks, with the addition of a modem to convert baseband digital signals to audio tones.[1]

The first TNC, the VADCG board, was originally developed by Doug Lockhart, VE7APU, of Vancouver, British Columbia.[2]

Amateur Radio TNCs were first developed in 1978 in Canada by the Montreal Amateur Radio Club and the Vancouver Area Digital Communications group. These never gained much popularity because only a bare printed circuit board was made available and builders had to gather up a large number of components.[specify]

In 1983, the Tucson Amateur Packet Radio (TAPR) association produced complete kits for their TNC-1 design. This was later available as the Heathkit HD-4040. A few years later, the improved TNC-2 became available, and it was licensed to commercial manufacturers such as MFJ.

In 1986, the improved "TNC+" was designed to run programs and protocols developed for the original TNC board. TNC+ also included an assembler and a version of Forth (STOIC), which runs on the TNC+ itself, to support developing new programs and protocols.[3]

In 2018 Nino Carillo (KK4HEJ) developed and produced a TNC (the NinoTNC)[4] with (currently) 16 different data modes, from 300 baud AFSK to 19,200 C4FSK.It has a KISS interface to the compute device, and implements IL2P (Improved Layer 2 Protocol)[5] for Forward Error Correction (FEC) in some modes.

  1. ^ R. Dean Straw, ed. (2005). The ARRL Handbook for Radio Communications 2006. American Radio Relay League. pp. 9.14–9.15. ISBN 0-87259-948-5.
  2. ^ Larry Kenney. "Introduction to packet radio".
  3. ^ Douglas Lockhart. (1986). "Features of the VADCG TNC+". Vancouver Amateur Digital Communications Group.
  4. ^ "TARPN -- NinoTNC info for Builders". tarpn.net. Retrieved 2024-09-01.
  5. ^ "TARPN: Improved Layer-2 Protocol". tarpn.net. Retrieved 2024-09-01.