Page 27 - EngineerIt January 2021

AMATEUR RADIO

Digital transformation secures

amateur radio’s future

igital transformation is the that radio amateurs embraced digital transformation as early as the 1960’s.
integration of digital technology The first major, and undoubtedly most popular, digital mode to be developed was packet
Dinto all areas of an activity; radio. It dates back to the mid-1960s and was put into practical application in the Arpanet,
amateur radio has not been immune from which was established in 1969. Initiated in 1970, the ALOHANET, based at the University of
digital transformation and is challenging a Hawaii, was the first large-scale packet radio project. Amateur packet radio began in
long history of analogue technology. Montreal, Canada, with the first transmission on 31 May 1978. This was followed by the
The headline “Digital transformation Vancouver Amateur Digital Communication Group (VADCG) development of a terminal
secures amateur radio’s future” is perhaps node controller (TNC) in 1980. At the time, the Southern African Amateur Radio Satellite
somewhat misleading because from the Association (now AMSAT SA) acquired two of these controllers and started experimentation
outset, amateur radio always had a digital locally. Soon after that, the first digipeater was set up in Johannesburg. The TNC standard
component, Morse code, keying a grew from a discussion in October 1981 at a meeting of the Tucson Chapter of the IEEE
transmitter on and off. Computer Society. A week later, six of the attendees gathered and discussed the feasibility
https://www.reddit.com/ has an interesting of developing a TNC that would be available to amateurs at a modest cost. The Tucson
take on this. Amateur Packet Radio Corporation (TAPR) was formed from this project. On 26 June 1982,
“Obviously radio waves by their nature Lyle Johnson, WA7GXD, and Den Connors, KD2S, initiated a packet contact with the first
are analogue, but the most rudimentary TAPR unit. The project progressed from these first prototype units to the TNC-1 and then
definition of digital is something finally to the TNC-2, which is now the basis for most packet operations worldwide.
represented by discrete values, which To provide a mechanism for the reliable transport of data between two signalling
Morse code is, as there are only two terminals, it is necessary to define a protocol that can accept and deliver data over a variety
options for representing something - dit or of types of communications links. The AX.25 link-layer protocol is designed to provide this
dah. That said, because Morse code is service, independent of any other level that may or may not exist. This protocol conforms to
transmitted on a continuous wave (CW) ISO Recommendations 3309, 4335 (including DAD 1&2) and 6256 high-level data link
and the nature of radio in general isn’t control (HDLC) and uses some terminology found in these documents. It also conforms with
Boolean, 0 isn’t a signal, it’s a lack of a ANSI X3.66, which describes ADCCP, balanced mode. This protocol follows, in principle, the
signal, but it could be represented in base CCITT X.25 recommendation, with the exception of an extended address field and the
3, 0 being the baseline, uninterrupted addition of the unnumbered information frame. It also follows the principles of CCITT
continuous wave, 1 and 2 being dit and Recommendation Q.921 (LAPD) in the use of multiple links, distinguished by the address
dah. There is nothing inherent to the
definition of digital that says that Is Morse code a digital communication mode?
something must be binary to be digital,
right? We use Boolean logic as it’s the
simplest explanation of how a switch
works, if a relay is open or closed, a valve
or transistor is passing a current or isn’t.
We can register either of those states as
a value, but with something like radio, 0
isn’t a value that can be registered, it’s a
lack thereof.”
Amateur radio has, from its inception,
displayed resilience, embraced change
and has continued to answer to the
International Telecommunication Union
(ITU) definition of amateur radio: “A radio
communication service for the purpose of
self-training, intercommunication and
technical investigations carried out by
amateurs, that is, by duly authorised
persons interested in radio technique
solely with a personal aim and without
pecuniary interest.” It is thus not surprising

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