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AMATEUR RADIO By GARRY CHATT, VK2YBX Introducing amateur radio With the ready availability of low-priced equipment, there's never been a better time to get started in amateur radio. Here's a quick rundown on what it's all about. Amateur Radio is an exciting hobby enjoyed by over 15,000 enthusiasts in Australia. It is a process of constant learning and acquisition of new skills through experimentation and discussion with enthusiasts with similar interests worldwide. Amateur radio allows access to the latest radio communications techniques and serves as an informal technology transfer on an international basis, often circumventing the red tape of commercial enterprise. The amateur station may be either mobile (ie, fitted to a vehicle) or installed at home in the "shack", allowing the enthusiast to talk to like-minded individuals over distances of hundred of kilometres, and even in other countries. Amateurs have long been recognised as leaders in the development of the more experimental and unconventional modes of transmission and communication techniques. Slow scan television, packet radio, satellite communications - all are now accepted methods for communication on a commercial basis and were pioneered by amateur radio operators. In fact, you could say that Marconi was a radio amateur of sorts! World exploration often relies on amateur radio. Thor Heyderdahl used amateur radio on his Kon Tiki and Ra expeditions, as did Dr David Lewis during his 1978 Antarctic ex- The Yaesu FT726R is a fully synthesised 10W transceiver capable of operating on the 6-metre, 2-metre and 70-centimetre bands. (Photo courtesy Dick Smith Electronics). 90 SILICON CHIP Yaesu's handheld FT73 covers the 430-440MHz UHF band and features digital tuning with 2W output. (Dick Smith Electronics). pedition, the British Trans Arctic expedition of 1968, and recently Dick Smith on his solo world helicopter flight. All used amateur radio as a safety net, knowing that in the event of an emergency they had access to amateur radio operators around the world. Often, amateur radio provides the only communication in and out of disaster areas. Amateurs played a vital part in the 1986 Mexico City earthquakes, Cyclone Tracy in 1974 and, more recently, the earthquakes in New Zealand. Amateur radio provided many vital communications links in the aftermath of each disaster. Amateur radio has also played a large part in the development of space communications hardware and techniques. Since the launch of the first amateur satellite, OSCAR 1, in December 1961, over 18 amateur Satellites have been launched into space. Some are still operating five years after launch. These successive orbiting packages show the enormous possibilities of space communications. The latest addition, JAS-1 (OSCAR 12), allows worldwide automatic message delivery via packet radio! Becoming an amateur To join the ranks of the amateur fraternity only a basic knowledge of electronics is required. You simply require enough knowledge to allow you to continue to build expertise through the enjoyment of your hobby. Basically, there are three entry points to the amateur radio license. Users select the level most suitable to their needs and are required to pass a written [multiple choice) examination to qualify to hold a licence to operate equipment on the amateur bands (see Table 1): (1). The AOCP (Amateur Operators Certificate of Proficiency), otherwise known as " the full call" , allows access to all bands and modes of operation authorised for amateur use. This means access to all HF, VHF and UHF amateur bands. (2). The LAOCP (Limited AOCP) restricts the available bands to VHF and UHF and does not allow CW operation. Many amateurs find that this level is sufficient for their social and technical needs. Consequently, in Australia, the majority of amateur activity occurs on the VHF and UHF bands. (3). The NAOCP or " Novice" license allows HF operation only at reduced power on selected bands. CW operation is permitted to 5 WPM. In addition to the above, the amateur operator may take out a combined "Novice" and " Limited" license (LAOCP/NAOCP). Full and Limited license applicants must obtain passes in examinations for theory and regulations. Full call applicants must also pass a Morse code examination at 10 words per minute (WPM). Novice licence applicants must pa ss a more elementary theory examination, regulations and Morse code at 5 WPM. Additional inform a tion on licences and exams can be obtained Table 1: Bands, Power and Modes of Operation Band Frequencies 160 metres 1.8-1.825MHz 1.825-1.875MHz Power (AV/PEP) Mode Licence 120/400W ALL* AOCP AOCP NAOCP 80 metres 3 .5-3 .8MHz 3 .525-3.625MHz 30W ALL AM/CW/SSB 40 metres 7 .00-7 .3MHz 120/400W ALL AOCP 30 metres 10.1-10.15MHz 120/400W ALL AOCP 20 metres 14.00-14.35MHz 120/400W ALL AOCP 17 metres 18.068-18.168MHz 120/400W ALL AOCP 15 metres 21.00-21.45MHz 21.125-21 .200MHz 120/400W ALL 30W AM /CW/SSB AOCP NAOCP 12 metres 24.89-24 .99MHz 120/400W ALL AOCP 10 metres 28.00-29.7MHz 28 .1-28.6MHz 120/400W ALL 30W AM /CW/SSB AOCP NAOCP 6 metres 50 .0-54.0MHz 120/400W ALL L/AOCP 2 metres 144-148MHz 120/400W ALL L/AOCP 70cm 420-450MHz 120/400W ALL L/AOCP 50cm 576-585MHz 120/400W ALL L/AOCP 23cm 1240-1300MHz 120/400W ALL L/AOCP 13cm 2300-2450MHz 120/400W ALL L/AOCP 3cm 10000-10500MHz 120/400W ALL L/AOCP 1.25cm 24000-24250MHz 120/400W ALL L/AOCP * Emissions authorised for the Amateur Service This do-it-yourself HF transceiver from Dick Smith Electronics can be built to cover any 500kHz segment between 2 and 30MHz. It features LSB, USB and CW modes and a power output of°30W PEP or 15W CW. Table 2: Recommended Texts for AOCP/LAOCP/NAOCP (1 ). (2) . (3) . (4) . (5) . (6) . (7) . (8). " VHF/UHF Manual" ; G. R. Jessop, 500 pages. " 1987 ARRL Handbook" . " Amateur Radio and Electronics Study Guide" ; Ian Ridpath, 21 O pages . " 1000 Questions for Novice Candidates"; Ken Hargreaves, Dave Wilson Rex Black; 11 6 pages. " 500 Questions for AOCP Candidates"; Bill Dunn , Fred Santos, Keith Hargreaves, Dave Wilson ; 94 pages . " Manual of Q & A for the Novice Licence "; Keith Howard ; 100 pages. " The Ham Exam Cram Book"; Keith Howard ; 72 pages. " The Amateur Operator's Handbook" ; Australia Government Publishing Service. from the Wireless Institute of Australia, PO Box 300, Caulfield South, Vic. 3162. To obtain an adequ a te knowledge of the principles of amateur radio, the enthusiast can NOVEMBE R1987 91 choose between correspondence courses, instruction classes at a local radio club, or self study of the recommended texts, available at bookshops, electronic retailers and some radio clubs (see Table 2). Most countries in the free Western World and some in the Eastern Bloc allow amateur operations. The international body which regulates international radio operations is called the International Telecommunications Union (ITU). Member countries subscribing to the ITU enforce regulations via their own government. In Australia, ITU recommendations are acted on by the Department of Transport and Communications (the new Federal government department which combines the old departments of Transport and Communications). The DOTC liases closely with the Wireless Institute of Australia (WIA) which represents amateurs in this country. Through the cooperation of the DOTC and the WIA, a number of other countries accept an Australian amateur radio licence as qualification to operate amateur radio equipment on a temporary basis (during vacation etc). This co-operation between regulatory bodies is called reciprocal licensing. Countries with reciprocal licensing are listed in Table 3. The works - this is the view inside Kenwood's TS-711A all-mode 2-metre transceiver. Note the use of LSI chips in the digital control unit (vertical board). The various sub-assemblies hinge out to enable access. (Reproduced by courtesy of Kenwood Australia). Callsigns All countries have been allocated radio callsign prefixes (Australia's prefix range VHA-VNZ) by the ITU. For the amateur service, Australia's prefix is VK. An amateur callsign is comprised of the national prefix (VK), a state prefix (a single numeral), and a Table 3: Countries with Reciprocal Licence Agreements USA UK NZ Canada West Germany Tonga India Eire Israel Belgium Denmark Vanuatu Fiji Morocco PNG Luxembourg Netherlands Japan Nigeria Norway Portugal Swaziland Sweden Brazil Table 4: Amateur Licences in Australia VK2 VK3 VK4 VK5 VK6 VK7 VK8 3061 2473 1517 1032 902 352 73 LAOCP 959 1037 389 276 221 104 25 NAOCP 946 772 619 332 212 99 49 LAOCP/NAOCP TOTAL: 16,661 362 303 266 122 97 41 20 AOCP 92 SILICON CHIP maximum of three identifiable letters; eg. VK2ABC. A survey of the numbers of amateur licenses on a state-by-state basis is shown in Table 4. Equipment The range of "off the shelf" equipment available to the radio amateur is enormous, and varied enough to suit all applications. The major source of equipment is Japan which is hardly surprising considering that the Japanese have an amateur population of 600,000. Major equipment brand names are Icom, Kenwood, Yaesu, Ten-Tee, KDK and FDK. There are many reputable firms selling radio equipment in Australia and, with such a relatively small market, pricing is always competitive. It's also worth noting that most amateur equipment attracts only 2 % import duty. The option of building your own equipment is also quite viable and virtually everything the amateur could need - power supplies, SWR bridges, preamplifiers, power amplifiers, receivers, transceivers and antennas etc - is available in kit form. We'll be describing projects like these in future issues. Transmission modes There are many modes of transmission authorised for amateur use, including AM, FM, CW, SSB, RTTY, FSK, SSTV and FAX. Some modes make efficient use of the RF spectrum, whilst others are somewhat wasteful; eg. SSB is more efficient than AM as far as distance versus power output is concerned because of the narrow bandwidth utilised. FM offers improved clarity over AM, while RTTY offers a high speed advantage over CW. These modes of transmission are given separate classifications, each having a distinct alphanumeric expression. The first four characters express the necessary bandwidth, (eg, 200H means a signal having 200 Hertz bandwidth). The next group of three characters indicate the type of modulation and the nature of the modulating signal (eg. A3E, where A = double sideband, 3 = a single channel containing analog information, and E = telephony). The last two characters are used to further describe the nature of the modulating signal and are rarely used in amateur radio. Table 5 gives a summary of these classes of these classes of emission. The three most common modes or emissions are: 100HA1A (100 Hertz CW), 2K70J3E (2.7kHz SSB), and 5K00F3E (5kHz NBFM). Table 5: Explanation of Class of Emission Designators First four characters: Bandwidth Fifth character: Amplitude Modulation A = Double sideband B = Single sideband, full carrier. R = Single sideband, adjustable carrier level. J = Single sideband, suppressed carrier. C = Vestigial sideband. Angle Modulation F Frequency modulation. G = Phase modulation . = Phase Modulation K = Amplitude modulation. L = Modulated in width/duration. M = Modulated in position/phase. Sixth character: Nature of the signals modulating the main carrier 1 = A single channel of quantised or digital information without a modulating subcarrier. 2 = A single channel of quantised or digital information using a modulating subcarrier. 3 = A single channel containing analog information. Seventh character: Type of information A = Telegraphy for aural reception (CW) B = Telegraphy for automatic reception (RTTY) C = Facsimile D = Data, telemetery, telecommand E = Telephony F = Television Eighth character: Details of signal K = Narrow band voice information. M = Monochrome television. N = Colour television. Ninth character: Multiplexing details N = None. Repeaters As previously mentioned, the most popular bands in Australia are the VHF and UHF bands. As a result, a huge network of repeaters has emerged, giving mobile to mobile coverage of up to 150km. As the predominant mode for repeater operation is NBFM (narrow band FM), the VHF/UHF repeater service serves to foster intense amateur activity in capital cities and regional centres. Most scanning receivers, by the way, cover the FM segment of the For the really serious amateur - Yaesu's FT767GX is a fully synthesised transceiver that covers all amateur bands from HF through to UHF (1.B-440MHz). Price is around $4995. (Dick Smith Electronics). 2-metre amateur band utilised for repeater operation. So, if you're interested in amateur radio, you can use your scanner to listen to the repeaters. Next issue, we'll look at the VHF /UHF bands in detail and show you how to listen to these bands. NOVEMBER 1987 93