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VOLUME III eCover and contents |
Science, People & Politics, issue 1 (Jan.- Mar.), VIII (2012), 23rd January.
As World regulators of commercially valuable electromagnetic resources
begin four weeks' of talks in Geneva today it is worth recalling what amateur radio
operators do with their slice of the pie.
by Helen Gavaghan
of transceiver used by Halifax (UK) & District Amateur Radio Society.
Solar maximum is just around the corner. Expected 2013. It is a phenomenon occurring every 11 years. A time when the higher levels of the atmosphere enveloping Earth are richest and most dense in the charged particles reflecting radio waves. It is when amateur radio operators might just contact Antarctica, from anywhere on the globe, and when ground-based and satellite amateur-radio, also called Ham radio, can contribute to scientific knowledge.
It is also when Earth's electromagnetic environment, from ground to magnetosphere, can be supercharged by solar eruptions, wreaking havoc on space-based and ground-based electronic and electrical equipment.
The reason? Electromagnetic radiation.
When you look at a rainbow the colours you see are wavelengths of electromagnetic radiation. Sunlight reflected, refracted and diffracted. Each of us has different visual acuity. Great artists, arguably, have greatness because they can see and reproduce shades from the natural world, such as a rainbow, more truly than the rest of us: shades of crimson and scarlet within the spread of reds, or turquoise and aqua among blues.
Amateur radio operators also work with the electromagnetic spectrum. In their case with invisible radio waves.
All electromagnetic radiation is energy in motion. It is created by the vibration of physical matter carrying an electrical charge. A process which is like, but is not the same, as the twang of a violin chord. Both processes have distant consequences.
Vibration of violin strings sets air in motion. Waves of varying air density carry the vibration, with decreasing loudness, outward - spherically, unless otherwise guided - until the listener hears each succeeding nuanced pressure of bow and finger on string.
When instead of a violin string an electric charge vibrates it is the ability of that charge to influence other charged material which spreads outwards in waves. Those waves being electromagnetic radiation. Waves of influence, characterisable as wave amplitude, wave frequency (number of waves per second) and wave orientation in three dimensions. Those characteristics can all be modulated to represent sound.
In mammals the detector of visible electromagnetic radiation is the retina. For amateur radio it is an aerial.
In vision the optic nerve carries the detected signal from retina to brain, where it becomes part chemical and part electrical energy. At each step information from the original signal can be lost, but eventually the brain reassembles the biochemistry and biophysics into something it can interpret as a rainbow, or some great work of art.
In amateur radio the carrier signal, undetectable unaided by the human ear, is fed from the aerial into electrical circuitry. If that signal has been modulated to carry sound by shaping the characteristics of its wavelengths, the sound representation can be disentangled by the electronics, and transduced to audible sound. If the wave characteristics are not modulated to carry sound then the signal when received still incorporates information, but the information is about the signal's emitter and the medium through which it has travelled.
Perhaps some retinas, in addition to discerning with greater acuity, are constructed to detect the twists and turns of light radiation, its polarity, phases, and the eddies in time of these physical properties. Shimmers and scintillations. Biology bestowing by genetic chance and protein construction an innate artistic advantage.
For amateur radio the aerials and receivers analogous to retinas, nerve and brain, are bought, or built, as part of the pleasure of the hobby. Wires, crystals, inductance loops, resistors and capacitors, guiding the radio wave from aerial through conversion to electrical energy.
Think of such a circuit as a giant sieve with holes of varying sizes, some limiting shape, others limiting by diaphragm, weight. Shake the sieve. Different sized and weighted material is sorted into different sized stones which land on, say, a suspended rubber mat, setting the mat vibrating, because of its elasticity, with a varying pattern of vibration.
My own imperfect analogy, unless I have a buried memory, and am inspired by William Heath Robinson.
The analogy expresses the abstract concepts common in music, vision and amateur radio. Each works only because energy is expressed vibrationally in three dimensions. Existing in both time and space the vibrational structure contains information about its origin and its natural environment, or has information imposed on it artificially by, say, the varying pressure of the violinist's fingers and arm.
An external power source, such as the violinist's arm, or an electrical power supply propels the vibration outwards, and another source of power - for example, Brownian motion, or the potential energy released in an adenosine triphosphate mediated conformational change, or the outer electron cloud of a conductor - provides a medium for transmission of the original vibrational energy and information content.
The same principles and concepts are at play for a visitor to an art gallery, a listener at a concert, or an amateur radio operator.
The common abstract concepts have a common language of expression that lets them be manipulated to predict or explain behaviour. The language? Mathematics. With the same mathematics the amateur radio operator, the sound engineer and the optician can all work with wave forms to do their tasks.
The visible spectrum works at wavelengths from 400 to 700 nanometres. Radio waves lie between 30 centimetres and 3 kilometres in length, though the Wireless Telegraphy Act of 2006 in the UK covers wireless frequencies not exceeding 3000 gigahertz (Section 116 of the Act).
It is the Wireless Telegraphy Act of 2006 and the Communications Act of 2003 which, in the UK, empower a regulator, Ofcom, to disburse licenses to qualified radio operators.
Amateur radio operators work with both ground and space-based equipment. I have met both types. In the US and, last year, in West Yorkshire in the UK.
When I met the Halifax (UK) and District Amateur Radio Society (Hadars) seven months ago they were mulling over how to enthuse young people to join them and to learn and explore through amateur radio the ideas of physics and maths.
I learned of the group from a note in a local newsletter. Because I had met amateur radio operators when living and working in Washington DC in the US, when researching a history of application satellites, I asked if I could write a story about what they do. They said yes.
In the US the ham radio hobbyists I'd met had all participated in detecting the first ever satellite to be launched. That satellite was Sputnik, lofted by the Soviet Union on October 4th., 1957. The work of the American amateurs I met
was a critical backstop to that of professional scientists.
Hadars, when I met them, was considering an event to be called Churches on the Air. The idea being that on Saturday 10th September, 2011 they'd go on air seeking contact with as many other amateur radio groups or individuals as were broadcasting and receiving from a church - any denomination. Other similar events take place around local canals, castles, lighthouses, anything which interests the group.
On the day of Churches on the Air I joined Hadars for several hours, keeping discretely out of the way as they battled a recalcitrant power supply and threaded aerial wire from an upstairs window, down and among foliage. Dials were twirled and the broadcasting of call signs began. Whilst I was there they heard from Germany, France and Russia. Other ham operators, like them, roaming the airwaves allocated for amateur radio in search of like minded people.
The Halifax group ranges in age from 26 to 84. Among them retired teachers, a man coming to terms with a diagnosis of muscular sclerosis, and a former second world war gunner were among those I met on the two occasions I sat in with Hadars. We do what we do for fun, "maybe you get a response from someone who is far away," said Esde Tyler, one of only two women in the group, and a former teacher and freelance technology journalist.
Theirs is a hobby for people who enjoy designing and building things and making them work. Technogeeks to my mind. One step ahead of train spotters, in their language. Though some of the society are retired science teachers others are only now in their middle or later years discovering applied science. Others have had a life-long interest in electronics and radio, and retirement has given them the opportunity to indulge their passion. For some it is also a social phenomenon. Meeting one another face to face, but also broadcasting to and listening - if conditions are right - to the world.
To be an amateur radio operator requires training and a licence, acquired after passing a multiple-choice exam. Because of the practical element required that training is easiest through groups such as Hadars. The chair of Hadars is Martin Cox. He is a recently retired computer programmer and helps train Air Training Force (ATF) cadets.
There are three levels of amateur radio licence in the UK. On average it takes about 6 months to acquire each of the three licences: foundation; intermediate; and full licence. It is possible to attend a crammer course and gain licences in a shorter time.
The foundation licence is an operator's licence and allows the holder low-power access to all the high-frequency and very-high-frequency wavebands allocated to radio amateurs, as well as some of the microwave bands. The intermediate licence is biased toward the practical, and the holder is allowed to use a higher power level as well as to make their own transmitters. The highest level of licence, the full licence, is more technical than the lower levels and allows the holder to use up to 400 watts. It is an internationally recognised qualification.
Some participants in local groups also provide radio communications in times of emergency such as for disaster-relief teams combating tsunamis, earthquakes and wide-area flooding. In the UK Ofcom is also discussing whether temporary release of frequencies is needed for the London Olympic and Paralympic games in London this year.
If you are a ham radio enthusiast with a passion also for space there are a number of satellites being built internationally and scheduled for launch, or raising funds for elements such as solar panels. Some will be aloft by 2013, the currently anticipated time of peak solar maximum activity. With solar maximum imminent Hadars and the worlds' Ham radio fans have a rich and rewarding few years to look forward to.
Ofcom is the independent regulator in the UK of radio waves for civil purposes. The UK Ministry of Defence controls others.
One minor error corrected within 24 hours.
The Radio Society of Great Britain.
http://www.rsgb.org/, accessed 19th January, 2012.
Radio Communications Foundation, FUN cube.
http://uk.virginmoneygiving.com/charity-web/charity/finalCharityHomepage.action?charityId=1001252, accessed 19th January, 2012.
Future satellites under development for amateur radio.
accessed 20th January, 2012.
FUNCube, UK amateur radio satellite educational satellite.
http://funcube.org.uk/, accessed 19th January, 2012.
Halifax (UK) & Distric Amateur Radio Society
The radio amateur satellite corporation.
http://www.amsat.org/amsat-new/index.php, accessed 19th January, 2012.
The William Heath Robinson Trust.http://www.heathrobinson.org/, accessed 20th January, 2012.
NOAA space weather prediction service.br>http://www.swpc.noaa.gov/, accessed 19th January, 2012.
Electromagnetic spectrum, a page from NASA.
http://science.hq.nasa.gov/kids/imagers/ems/radio.html, accessed 20th January, 2012.
NASA Goddard. The cultural references might be out of date, but the physics isn't
http://imagine.gsfc.nasa.gov/docs/science/know_l1/emspectrum.html, accessed 19th January 2012.
NASA Goddard, solar dynamics observatory.
http://sdo.gsfc.nasa.gov/data/, accessed 22nd January, 2012.
Wireless Telegraphy Act 2006.
http://www.legislation.gov.uk/ukpga/2006/36/contents, accessed 22nd January, 2012.
Ofcom. Britain's wireless telegraphy regulator.
http://www.ofcom.org.uk/, accessed 20th January, 2012. Section 115 is particularly interesting.
The International Telecommunications Union.
For those with a serious intent to work in radio.
http://www.itu.int/en/Pages/default.aspx, accessed 19th January, 2012.
The World Radio Communications Conference (23rd January to 17th February 2012).
Cabinet official committee on UK spectrum strategy (2010).
http://stakeholders.ofcom.org.uk/binaries/spectrum/spectrum-policy-area/spectrum-management/ukfat2010.pdf, accessed 20th January, 2012.
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