Page 35 - EngineerIT November 2021

AMATEUR RADIO

audiences at many of his public lectures.
“My own psychological bent, insofar as it has The Nobel Prize in Physics 1993 was awarded jointly to
Russell A. Hulse and Joseph H. Taylor Jr. “for the discovery
influenced any professional decisions, is to
of a new type of pulsar, a discovery that has opened
pursue a path promising enjoyment along the
up new possibilities for the study of gravitation.”
way, without looking too far ahead. Perhaps
related to my Quaker upbringing, I’ve always Pulsars are very compact stars that radiate radio
valued personal involvement in a difficult waves with very regular variations. In 1974 Joe Taylor
task over appeals to eminence or authority; and Russell Hulse discovered a pulsar comprised of
I like the challenge of re-examining a two stars in very close proximity that rotate around each
problem from fresh perspectives. Ultimately, other. Taylor and Hulse could demonstrate that the stars’
I believe that in important matters we are radiation and movements correspond with Albert’s general
mostly self-taught, but in a way that is theory of relativity. Among other things, this theory predicts
that the pulsar would emit energy in the form of gravitational waves,
strongly reinforced by cooperative human
which should result in slowly declining intervals. Taylor was able to confirm this in 1978.
relationships. I have worked in two extremely
stimulating intellectual environments, first
at the University of Massachusetts and more conversations, or “ragchewing.” Rather, they concentrate on efficient exchange of such basic
recently at Princeton. information as call signs, Maidenhead grid locators, signal reports and acknowledgments at the
In 2012 Joe Taylor shared his vison for the lowest possible signal-to-noise ratios, in the space of a few minutes or less. Short user messages
future of communication when he addressed are encoded into audio-frequency waveforms that can be transmitted and received with standard
the World Radiocommunication Conference SSB transceivers. At the receiving end, recovered audio is converted back to digital samples
(WRC-12). He said that future technologies and the software carries out a reverse transformation to decode the message. All transmissions
will surely make even better uses of wireless are timed and synchronised with Coordinated Universal Time (UTC). The first publicly available
communication than we do today. version of WSJT1 was designed for meteor scatter on the VHF bands. The software has been under
“I foresee plenty of scope for continual development since 2001, with improved performance, added user-convenience features
contributions for new technologies. and new operating modes. The current program version supports four modes that use 1-minute
Information and communication technologies transmit/ receive (T/R) sequences.
have much to offer for the betterment of The oldest of the slow modes, JT65, was designed for Earth-Moon-Earth (EME)
the human condition everywhere, and communications and is widely used for that purpose today. However, even greater usage of JT65
perhaps especially so in the developing (and the newer modes, JT9 and FT8) can be found in spectral slices only a few kilohertz wide on
world. It is extremely important to continue bands from 160 through 6 metres.
seeking the best efficiencies in the use of the FT8 is today the most common WSJT protocol. It is open source with continual development
spectrum.” He certainly demonstrated that by small teams of radio amateurs. FT8 stands for “Franke and Taylor 8-FSK” modulation. Joe had
in post-retirement amateur radio weak signal some help on this one from Steven Franke, K9AN. FT8 is designed to maximise communication
communication projects. even when signals are very weak (as low as -24dB). This means that even low-powered stations
On another occasion he said that since and stations with sub-optimal antennas can make contacts worldwide. This was recently
the 1930s, radio amateurs have known that demonstrated by several South Africa Radio Amateurs when they made contacts with their
worldwide communication is possible on European counterparts on 50 MHz even while the sunspot count was low.
the HF bands (at least some of the time) Joe Taylor’s path to success is testimony that amateur radio is a great primer for career
with power levels no more than 100 W and choices in science and technology, and a life-long activity with endless opportunities. n
antennas as simple as half-wave dipoles.
Twenty-first century digital communication
techniques based on information theory
make these things possible at much lower
power levels, even with compromised
antennas. Optimised methods of coding and
modulation enable these and many other
surprising feats such as using reflections
from ionised meteor trails; and Earth-Moon-
Earth (“moonbounce”) contacts using the
moon as a reflector of radio signals, covering
worldwide distances.
Starting in 2001, Joe Taylor’s software
program WSJT has facilitated making two-
way contacts with extremely weak signals.
The latest version of this open-source,
multiple-author software package is called
WSJT-X. It supports nine distinct protocols
or modes, each optimised for a different
frequency range or type of propagation.
These modes are not designed for long FT8 Screenshot

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