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AMATEUR RADIO By GARRY CRATT, VK2YBX Amateur radio in the VHF bands Most amateur activity in Australia occurs on the VHF bands. Here's how to listen in to these bands, plus a list of amateur repeater stations. The VHF bands provide an excellent outlet for both the social and technical needs of the radio amateur. The equipment required to operate on these bands is widely available and ranges from modified commercial FM equipment to stateof - the - art amateur radio equipment. The large concentration of repeaters in the 144-148MHz (2-metre) band confirms its popularity - Fig.1. Normally located at well elevated sites, repeaters provide enhanced mobile coverage of up to 150km, a vast improvement over the 20-30km 'line of sight' normally achievable using single frequency mobile communications. Such repeaters provide the ideal medium for regular daily 'rag chewing' for many amateurs whilst mobile to and from work, and also provide a signal source for experimentation with high gain antennas and other equipment for those interested in the technical pursuits of amateur radio. For the newcomer wishing to listen to FM communications on the VHF amateur bands, the scanning receiver offers a wide frequency l Fig.3: the discone antenna is used by many amateurs and can provide wideband coverage from 50-500MHz. A FREQUENCY DIMENSION A (cm) DIMENSION B (cm) 52MHz 146MHz 438MHz 137 49 16 144 51 17 Fig.2: this simple but effective groundplane antenna can be made for just a few dollars. It can be cut to cover either the 6-metre, 2-metre or 70cm band. range for a modest investment. Many scanning receivers cover the 6-metre (50-54MHz), 2-metre (144-148MHz) and 70cm (420-450MHz) bands, and a simple but effective groundplane antenna at the relevant frequency can be made for just a few dollars - see Fig.2. Alternatively, a wideband antenna called a 'discone' may be employed to cover all VHF bands. A typical VHF discone antenna covers 50-500MHz, and provides a gain of 3dB (Fig.3). For those enthusiasts interested in modes of communication other · than FM, the lower 2MHz of the 6-metre band and the lower 1MHz of the 2-metre band are normally DECE MB ER1987 73 Fig. 1: Operational VHFIUHF Repeaters in Australia TWO METRE REPEATERS A.C.T AREA CALL Canberra ACT VK1RAC 6900 Black Hill VK1RGI 6950 Mt. Ginini CHAN SITE NEW SOUTH WALES Coffs Harbour VK2RCH 6650 Bruxner Park W. Blue Mountains VK2RDX 6650 Mt. l3indo Moree/lnverell VK2RMI 6650 Terry Hie Hie VK2RTY 6675 Terry Hills Sydney Orange VK2RAO 6700 Mt. Canobolas Ulladulla VK2RMU 6700 Milton Pt. Macquarie VK2RPM 6700 Taree Gosford VK2RAG 6725 Somersby Bega VK2RFS 6750 Mt. Mumbulla Tamworth VK2RTM 6750 Mt. Crawney VK2RWG 6750 Mt. Flackney Wagga W'bungles VK2RCC 6800 Needle Mtn Lismore VK2RI C6800 Parrots Nest Sydney-Metro VK2RLE 6800 Heathcote Gunnedah VK2RAB 6850 Porcupine Res. Wollongong VK2RAW 6850 Mt. Murray Griffith VK2RGF 6850 Mt. Bingar Sydney-Nth VK2RMB 6875 Terry Hills Beaches VK2RAN 6900 Mt. Sugarloaf Newcastle Condobolin VK2RRT 6900 Boona Mount Syd-Lower N. Shore VK2RGR 6925 North Ryde N.England Tableland VK2RNE 6950 Mt. Rumbee Sydney-Metro VK2RWI 7000 Dural Blue Mountains VK2RMB 7050 Mt. Tomah Syd-E. Suburbs VK2ROT 7075 Paddington Newcastle VK2RTZ 7100 Mt. Sugarloaf Grenfell VK2RWM 7100 Grenfell Sydney Emergency VK2RWS 7150 Chats wood State Wide VK2RSD 7200 Mt. Emerg. Cambewarra VK2RST 7225 Lane Cove Sydney West Syd-Upper N.Shore VK2RNS 7250 Hornsby N. Wollongong VK2RIL 7275 Sublime ~oint VK2RHR 7350 Bowral Mittagong Syd-Sth West VK2RLD 7375 Razorback Shepparton Melbourne Corryong Quyen Melbourne Ballarat VICTORIA VK3RGV 6650 VK3RML 6700 VK3RNC 670 VK3RON 6700 VK3RPA 6700 VK3RBA 6750 Latrobe Valley Mildura Mt. Macedon East Gippsland Swan Hill Grampians Geelong Wodonga Omeo Robinvale Warrnambool VK3RLV VK3RMA VK3RMM VK3REG VK3RSH VK3RWZ VK3RGL VK3RNE VK3RGO VK3RVL VK3RWL 74 6800 6800 6850 6900 6900 6950 7000 7000 7050 7050 7050 SILICON CHIP Mt. Wombat Mt. Dandedong Mt. Mittamattie Quyen St. Albans Mt. Bunningyong Mt. Tassie Mildura Airport Mt. Macedon Donalds Knob Swan Hill Mt. William Mt. Anakie Mt. Big Ben Mt. Livingstone Robinvale Mt. Warrnambool Bright S. Gippsland Geelong Bendigo Melbourne W. Gippsland Melbourne Wodonga VK3RPB VK3RSG VK3RGC VK3RCV VK3REC VK3RWG VK3RTY VK3RPN 7100 7100 7125 7150 7175 7225 7350 7600 Mt. Porepunkah Bass Hill Montepellier Mt. Alexandria Mt. Dandenong Warragul Mt. Dandenong Mt. Stanley QUEENSLAND Rockhampton VK4RAR 6700 Rockhampton Townsville VK4RAT 6700 Mt. Stuart Gold Coast VK4RGC 6700 Mt. Tambourine Darling Downs VK4RDD 6750 Mt. Mowbullan Bundaberg VK4RBU 6800 Mt. Goonaneman North Coast VK4RNC 6850 N. Nambour Ipswich VK4RAI 6900 Mt. Crosby Gladstone VK4RGB 6900 Caliope Range Cairns VK4RCA 6950 Mt. Bellenden Ker Brisbane VK4RBN 7000 Mt. Glorious VK4RMK 7000 Nth Mackay Mackay Brisbane VK4RBT 7050 Mt. Cotton Brisbane VK4RAG 7150 Springhill Bundaberg VK4RBS 7250 Mt. Goonaneman SOUTH AUSTRALIA Port Pirie VK5RMN 6700 The Bluff Adelaide VK5RHO 6850 Houghton Mt. Gambier VK5RMG 6900 Mt. Gambier Adelaide VK5RAD 7000 Craters Alice Springs VK5RCA 7000 Alice Springs WESTERN AUSTRALIA Bunbury VK6RSW 6650 Bunbury Albany VK6RAL 6700 Albany Perth VK6RAP 6700 Roleystone Wyndham VK6RWH 6700 Wyndham Wickham VK6RWK 6700 Wickham Perth VK6RTH 6750 Tic Hill Albany VK6RAA 6800 Mt. Barker Perth VK6RTH 6800 Tic Hill Karratha VK6RWP 6800 Karratha Exmouth VK6REX 6850 Tower Zero Kambalda VK6RKB 6850 Kambalda VK6RBY 6900 Mt. William Bunbury Mt. Newman VK6RMN 6900 Mt. Newman Perth VK6RPD 6950 W.A.I.T. Bentley Emergency VK6REE 6975 Kalgoorlie VK6RAK 7000 Kalgoorlie Wagin VK6RAW 7000 Mt. Latham Emergency VK6REE 7000 Geraldton VK6RGN 7000 Geraldton Port Hedland VK6RNW 7000 Port Hedland Perth VK6RTY 7050 Nedlands Perth VK6RWC 7100 Doubleview Cataby VK6RCT 7200 Cataby Boddington VK6RMS 7250 Mt. Saddleback Eneabba VK6REN 7300 Ocean Hill Busselton VK6RBN 7350 Busselton North West Hobart North West Coast East Coast North East Coast TASMANIA VK7RAD 6625 Mt. Duncan VK7RHT 6700 Mt. Wellington VK7RNW 6750 Ulverstone VK7REC 6900 Snow Hill VK7RAA 7000 Mt. Barrow 70cm REPEATERS A.C.T. VK1RGI 8525 Mt. Ginini Canberra NEW SOUTH WALES Southern Highlands Gosford Sydney N. Beaches Wollongong SydneyEmergency N. Coast-Taree Blue Mountains Syd-S Suburbs Syd-W Suburbs Sydney-Metro Newcastle Newcastle Lismore N. Wollongong Melbourne Melbourne Gippsland Melbourne Wodonga Mildura Grampians Mt. Macedon Banalla Melbourne VK2RTK 8025 Bowral VK2RAG 8074 Somersby VK2RMB 8175 Terrey Hills VK2RUW 8225 Port Kembla VK2RWS VK2REE VK2RUT VK2RUH VK2RRS VK2RWI VK2RUM VK2RAN VK2RSC VK2RIL 8275 8325 8375 8425 8525 8525 8625 8625 8675 8725 VICTORIA VK3RMU 8074 VK3ROU 8225 VK3RGU 8375 VK3RAD 8525 VK3RNU 8525 VK3RRU 8525 VK3RWU 8675 VK3RCU 9275 VK3RDU 9425 VK3RPU 9725 Chatswood Taree District Kurrajong Hurstville Parramatta Dural New Lambton Mt. Sugarloaf Mt. Nardi Sublime Point Mt. St. Leonard Mt. Dandedong Carrajung Mitcham Mt. Stanley Merbein Mt. William Mt. Macedon Chassney Vale Arthurs Seat QUEENSLAND VK4RNC 8074 Mt. Nambour VK4RGC 8225 Mt. Tambourine VK4RWM 8375 Ipswich VK4RBC 8525 Mt. Cootha VK4RBU 8675 Mt. Goonaneman SOUTH AUSTRALIA VK5RWI 8525 Craters North Coast Gold Coast Brisbane Brisbane Bundaberg Adelaide WESTERN AUSTRALIA VK6RUF 8525 Roleystone Perth Hobart TASMANIA VK7R TC 8600 Mt. Nelson North East VK7RAB 8550 Mt. Arthur SIX METRE REPEATERS NEW SOUTH WALES VK2RWI 3850 Dural (Proposed) VICTORIA Melbourne VK3RTN 3675 Mt. Dandedong Melbourne VK3MH 3900 Hurstbridge Sydney WESTERN AUSTRALIA Perth VK6RSM 3200 Tic Hill Note: repeater offsets (ie, the difference between input and output frequencies) vary depending on the VHF band. 2-metre repeaters utilise a 600kHz offset; ie, the repeater transmits 600kHz higher than the received frequency. 70cm repeaters use a 5MHz offset, while 6-metre repeaters use a 1MHz offset. Fig.5: International VHF/UHF Beacons SIX METRE BAND FREQUENCY 50.010MHz 50.075 50.090 51 .020 51.030 52.013 52 .020 52.100 52 .200 52 .225 52 .250 52.310 52.320 52 .325 52.345 52.350 52.370 52.418 52.420 52.425 52.435 52.440 52.450 52.460 52.465 52.470 CALL SIGN JA2IGY VS6SIX KH6EQI ZL 1UHF ZL2MHB P29BPL FK8AB ZK2SIX VK8VF ZL2VH2 ZL2VHM ZL3MHF VK6RTT VK2RHV VK4ABP VK6RTU VK7RST VK0MA VK2RSY VK2RGB VK3RMV VK4RTL VK5VF VK6RPH VK6RTW VK7RNT LOCATION Nagoya Hong Kong Honolulu Auckland Hawkes Bay Loloata Island Noumea Niue Darwin Tarana ki Manawatu Christchurch Wickham Newcastle Long reach Kalgoorlie Hobart Mawson Base Sydney Gunnedah Hamilton Townsville Mt. Lofty Perth Albany Launceston reserved for CW and SSB modes of communication. Here, extensive use is made of multiple element directional antennas (yagis) and low noise receiver preamps to extract the maximum possible performance from equipment and so provide communications over reasonable distances. In fact communications over enormous distances can be achieved when atmospheric and ionospheric conditions are favourable (see Fig.6). To enable operators to be alerted to these favourable conditions, an international network of VHF beacons operates normally on a 24-hour basis. Thus, if an enthusiast in Australia is particularly interested in communicating with New 52.485 52.490 52.510 VK8RAS ZL2SIX ZL2MHF Alice Springs Blenheim Mt. Climie TWO METRE BAND 144.019 144.400 144.410 144.420 144.430 144.465 144.470 144.480 144.485 144.550 144.565 144.600 144.800 144.950 145.000 145.100 145.150 145.175 145.200 145.225 145.280 145.300 145.400 145.425 VK6RBS VK4RTT VK1RCC VK2RSY VK3RTG VK6RTW VK7RMC VK8VF VK8RAS VK5RSE VK6RPB VK6RTT VK5VF VK2RCW VK6RPH ZL 1VHF ZL1VHW ZL 1VHR ZL2UHF ZL2VHT ZL2VHN ZL3VHF ZL4VHF ZL4VHI Busselton Mt. Mowbullan Canberra Sydney Glen Waverley Albany Launceston Darwin Alice Springs Mt. Gambier Port Hedland Wickham Mt. Lolly Sydney Perth Auckland Hamilton Rotorua Wellington Taranaki Takaka Christchurch Dunedin lnvercargill Zealand on the 2-metre band, propagation conditions can be determined by monitoring the ZL 1VHF beacon frequency of 145.100MHz. Fig.5 shows a list of VHF beacons currently operating. When atmospheric and ionospheric conditions are favourable, FM communications on the VHF bands are often achievable over hundreds of kilometres. The VHF bands also provide access to many amateur spacecraft. The latest amateur satellite OSCAR 12 (J AS-1) uses a series of uplink frequencies in the 2-metre band and corresponding downlinks in the 70cm band. Provided low loss cable and low noise receiver preamplifiers are used it is quite normal to be able to communicate 70cm BAND 432.057 432.160 432.410 432.420 432.440 432.445 432.450 432.535 432.535 432.540 433.000 433.080 433.150 433.200 433.225 433.250 VK6RBS VK6RPR VK6RTT VK2RSY VK4RBB VK4RIK VK4RTL VK3RAI VK3RMB VK4RAR ZL2UHF ZL2VHN ZL1VHW ZL3UHF ZL2VHT ZL2VHP Busselton Nedlands Wickham Sydney Brisbane Cairns Townsville Macleod Mt. Buninyong Rockhampton Wellington Takaka Hamilton Christchurch Taranaki Manawatu 23cm BAND 1296.171 1296.420 1296.480 1297.000 1297.100 1297.150 1297.225 VK6RBS VK2RSY VK6RPR ZL2UHF ZL1UHF ZL1VHW ZL2VHT Busselton Sydney Nedlands Wellington Auckland Hamilton Taranaki via such satellites using very modest power levels (10W or less). Fig.6: Australian Distance Records BAND 50MHz 144MHz 432MHz 576MHz 1296MHz 2300MHz 3300MHz 5650MHz 10,000MHz STATIONS VK8GB to 9Y 4LL VK4ZSH to JA70XL VK3ZBJ to VK6KZ VK4ZRF to VK4ZSH VK6KZ to VK5MC VK5QR to VK6WG VK3KAJ to VK3ZBJ VK2AHC to VK2SB/VK2ZND VK3KAJ to VK3ZBJ DATE 10/4/82 24/4/83 23/1 /80 7/12/81 23/1 /80 17/2/78 25/1 /86 12/4/75 8/2/86 DISTANCE (km) 18,665 6617 2716 378 2289 1885 246 114 262 The Uniden BClOOXL scanner (Santronic Agencies, Kings grove). DECEMHER1987 75