HF LINK COMUNICAÇÕES DE EMERGÊNCIA
-----Mensagem original-----
De: cluster-bounces@radio-amador.net
[mailto:cluster-bounces@radio-amador.net]
Em nome de João Gonçalves CostaEnviada: sexta-feira, 13 de Julho de 2007 12:21
Para: Resumo Noticioso Electrónico ARLA
Assunto: ARLA/CLUSTER: HFLink - Automatic Link Establishment
-
Prezados Colegas,
Mais uma vez os radioamadores americanos, com destaque para a grandeespecialista aposentada do Exercito Norte-Americano, Bonnie Crystal-KQ6XA,não param e já se encontra desde 26 Junho passado, em franco desenvolvimentoum sistema automático global de comunicações de emergência, e não só,recorrendo a um software aberto muito parecido com o que usam os militares ealgumas ONG`s em HF há bastantes anos. Basicamente, o software ALE-Automatic Link Establishment assenta em 42 canais pre-seleccionados distribuídos pelas diferentes bandas de amadorentre os 160m e os 2m, sendo 9 desses canais globais e em HF.
O programaversátil permite manter uma rede global ou local, sendo as frequênciasseleccionadas automaticamente em função das condições de propagação,distancia, ruido,tipo de msg,antenas disponiveis, etc.O operador não procura qual a melhor frequência para o contacto, esta éseleccionada automaticamente pelo software que realiza um scanner continuopelos canais e avalia permanentemente as condições em função das msg que sãonecessárias enviar. Como sabemos, realizar contactos por voz ou em PSK31 nãoé a mesma coisa, nem são necessários os mesmos requisitos técnicosAssim, a preocupação constante de procurar uma frequência nas diferentesbandas, recorrendo a previsões de propagação, a beacons, etc, onde existamcondições hipoteticas para o contacto deixa de ser importante, o sistema
possível estabelecer comunicações.\u003cbr /\>\u003cbr /\>O transceptor administrado pelo sistema procura constantemente e em tempo\u003cbr /\>real manter a rede interligada ou o contacto ponto a ponto sem que os\u003cbr /\>operadores tenham de procurar. Basicamente todos os transceptores que possam\u003cbr /\>ser controlados via PC podem ser usados, no entanto, existem alguns modelos\u003cbr /\>onde é mais facil a integração, exemplos:\u003cbr /\>\u003cbr /\>ICOM\u003cbr /\>IC746, IC746PRO, IC7400, IC756PRO (Milspec 1030E-DSP), IC756PRO2, IC756PRO3,\u003cbr /\>IC765, IC775, IC781, IC7800 (\u003cbr /\>\u003cbr /\>KENWOOD\u003cbr /\>All Kenwood models after, but excluding the TS-440, PA relays handled by use\u003cbr /\>of SPLIT VFO, all support up to 2 ch/sec scan rate, newer models at 9600\u003cbr /\>baud up to 5 ch/sec and those at 19,200 baud at 10 ch/sec scan rate\u003cbr /\>\u003cbr /\>YAESU\u003cbr /\>FT-920, FT-990 with SPLIT VFO (FT-890 with special QS/S modification) all\u003cbr /\>can do up to 2 ch/sec scan rate\u003cbr /\>\u003cbr /\>Neste momento a rede Global ao nível dos EUA é contituida por 6 estações\u003cbr /\>piloto automáticas trabalhando 24H e 7 dias por semana, equipadas com o\u003cbr /\>sistema de scanning ALE, Antenas multibanda e um software especial de\u003cbr /\>controlo, que pode ser comandado e acedido via Internet.\u003cbr /\>\u003cbr /\>O sistema está em expansão constante com integração de novas\u003cbr /\>funcionalidades, exemplo; msg tipo SMS aos membros enviadas da Internet,\u003cbr /\>telefone móvel ou vice-versa. Os promotores esperam alargar rapidamente este\u003cbr /\>projecto ao nível planetário.\u003cbr /\>\u003cbr /\>Os requisitos básicos são:\u003cbr /\>- Um Computador, preferencialmente portátil.\u003cbr /\>- Um transceptor.\u003cbr /\>- Um conjunto de antenas multibanda comutadas ou comandadas\u003cbr /\>automaticamente.(não pensem que é preciso ANTENAS DIRECIONAIS TIPO\u003cbr /\>LOG-PERIÓDICA, ler a explicação e conselho mais abaixo dadas pela Bonnie\u003cbr /\>Crystal-KQ6XA)\u003cbr /\>\u003cbr /\>Para mais informações podem aceder á página do HFLINK Group em:\u003cbr /\>\u003ca onclick\u003d\"return top.js.OpenExtLink(window,event,this)\" href\u003d\"http://hflink.com/\" target\u003d_blank\>",1]
);
//-->
encarregasse de seleccionar este importante parâmetro sem o qual não épossível estabelecer comunicações.O transceptor administrado pelo sistema procura constantemente e em temporeal manter a rede interligada ou o contacto ponto a ponto sem que osoperadores tenham de procurar. Basicamente todos os transceptores que possamser controlados via PC podem ser usados, no entanto, existem alguns modelosonde é mais facil a integração, exemplos:ICOMIC746, IC746PRO, IC7400, IC756PRO (Milspec 1030E-DSP), IC756PRO2, IC756PRO3,IC765, IC775, IC781, IC7800 (KENWOODAll Kenwood models after, but excluding the TS-440, PA relays handled by useof SPLIT VFO, all support up to 2 ch/sec scan rate, newer models at 9600baud up to 5 ch/sec and those at 19,200 baud at 10 ch/sec scan rateYAESUFT-920, FT-990 with SPLIT VFO (FT-890 with special QS/S modification) allcan do up to 2 ch/sec scan rateNeste momento a rede Global ao nível dos EUA é contituida por 6 estaçõespiloto automáticas trabalhando 24H e 7 dias por semana, equipadas com osistema de scanning ALE, Antenas multibanda e um software especial decontrolo, que pode ser comandado e acedido via Internet.O sistema está em expansão constante com integração de novasfuncionalidades, exemplo; msg tipo SMS aos membros enviadas da Internet,telefone móvel ou vice-versa. Os promotores esperam alargar rapidamente esteprojecto ao nível planetário.Os requisitos básicos são:- Um Computador, preferencialmente portátil.- Um transceptor.- Um conjunto de antenas multibanda comutadas ou comandadasautomaticamente.(não pensem que é preciso ANTENAS DIRECIONAIS TIPOLOG-PERIÓDICA, ler a explicação e conselho mais abaixo dadas pela BonnieCrystal-KQ6XA)Para mais informações podem aceder á página do HFLINK Group em:
.\u003cbr /\>\u003cbr /\>Entretanto, deixo-vos algumas explicações em inglês dadas pela excepcional\u003cbr /\>Amadora de Rádio norte-americana, Bonnie Crystal-KQ6XA\u003cbr /\>\u003cbr /\>João Costa\u003cbr /\>CT1FBF\u003cbr /\>\u003cbr /\>\u003cbr /\>What is ALE?\u003cbr /\>ALE is the humorous acronym for the lofty-sounding Automatic Link\u003cbr /\>Establishment. It is the de-facto worldwide standard for initiating\u003cbr /\>communications using High Frequency radio. HF radio conveys signals via\u003cbr /\>ionospheric propagation, which is a constantly changing medium. With the\u003cbr /\>capability to call up a specific station, a group of stations, a net, a\u003cbr /\>networked station, or just CQ, ALE is a versatile system for connecting\u003cbr /\>radio operators for voice, data, text, instant messaging, internet\u003cbr /\>messaging, or image communications. A radio operator initiating a call, can\u003cbr /\>within minutes have the ALE automatically pick a frequency that has a good\u003cbr /\>propagation path. It signals the operators on both ends, so they can begin\u003cbr /\>communicating with each other immediately. In this respect, it can eliminate\u003cbr /\>the longstanding need for repetitive calling on pre-determined time\u003cbr /\>schedules and monitoring static on HF radios. It is a great tool for finding\u003cbr /\>optimum ionospheric propagation between stations in real-time, while\u003cbr /\>avoiding guesswork, beacon listening, and complicated HF prediction charts\u003cbr /\>altogether. These days, ALE is most commonly used for hooking up operators\u003cbr /\>for voice communications on SSB and for internet messaging, but there are\u003cbr /\>many other useful features.\u003cbr /\>\u003cbr /\>\u003cbr /\>How ALE Works\u003cbr /\>Each radio ALE station uses a callsign or address in the ALE controller.When\u003cbr /\>not actively in communication with another station, each HF SSB transceiver\u003cbr /\>constantly scans through a list of frequencies, listening for its callsign.\u003cbr /\>To reach a specific station, the caller simply enters the callsign just like\u003cbr /\>dialing a phone number. The ALE controller selects the best available\u003cbr /\>frequency and sends out brief selective calling signals containing the\u003cbr /\>",1]
);
//-->
http://hflink.com/ .Entretanto, deixo-vos algumas explicações em inglês dadas pela excepcionalAmadora de Rádio norte-americana, Bonnie Crystal-KQ6XAJoão CostaCT1FBFWhat is ALE?ALE is the humorous acronym for the lofty-sounding Automatic LinkEstablishment. It is the de-facto worldwide standard for initiatingcommunications using High Frequency radio. HF radio conveys signals viaionospheric propagation, which is a constantly changing medium. With thecapability to call up a specific station, a group of stations, a net, anetworked station, or just CQ, ALE is a versatile system for connectingradio operators for voice, data, text, instant messaging, internetmessaging, or image communications. A radio operator initiating a call, canwithin minutes have the ALE automatically pick a frequency that has a goodpropagation path. It signals the operators on both ends, so they can begincommunicating with each other immediately. In this respect, it can eliminatethe longstanding need for repetitive calling on pre-determined timeschedules and monitoring static on HF radios. It is a great tool for findingoptimum ionospheric propagation between stations in real-time, whileavoiding guesswork, beacon listening, and complicated HF prediction chartsaltogether. These days, ALE is most commonly used for hooking up operatorsfor voice communications on SSB and for internet messaging, but there aremany other useful features.How ALE WorksEach radio ALE station uses a callsign or address in the ALE controller.Whennot actively in communication with another station, each HF SSB transceiverconstantly scans through a list of frequencies, listening for its callsign.To reach a specific station, the caller simply enters the callsign just likedialing a phone number. The ALE controller selects the best availablefrequency and sends out brief selective calling signals containing the
characters of its callsign, it stops scanning and stays on that frequency.\u003cbr /\>The two stations\' ALE controllers automatically handshake to confirm that a\u003cbr /\>link is established and they are ready to communicate. The receiving\u003cbr /\>station, which was muted up until now, will typically emit an audible alarm\u003cbr /\>and visual alert for the receiving operator of the incoming call. It also\u003cbr /\>indicates the callsign of the linked station. The operators then can talk in\u003cbr /\>a regular conversation. At the conclusion of the QSO, one of the stations\u003cbr /\>sends a disconnect signal to the other station, and they each return their\u003cbr /\>ALE stations to the scanning mode. Some military / commercial HF\u003cbr /\>transceivers are available with ALE options. Amateur radio operators\u003cbr /\>commonly use the PCALE soundcard software ALE controller, interfaced to a\u003cbr /\>ham transceiver via RS-232 CAT port, multi-frequency antenna.\u003cbr /\>\u003cbr /\>Multi-Frequency Antennas Systems.\u003cbr /\>The Autotuner Inverted-V-Fan-Dipole and Autotuner V-Fan-Dipole\u003cbr /\>Design and Installation Notes by Bonnie Crystal KQ6XA\u003cbr /\>\u003cbr /\>Background\u003cbr /\>Various versions of multi-wire dipole antennas are known and widely used. HF\u003cbr /\>inverted-V antennas called "maypole" antennas, have been utilized with\u003cbr /\>dipoles resonant in the amateur bands. The most common has been the\u003cbr /\>3.8MHz/7.1MHz resonant version fed with 50ohm coax. Technically, the antenna\u003cbr /\>system consists of two or more dipoles of different lengths arranged\u003cbr /\>radially in inverted-Vee form with a single common feedpoint. There are\u003cbr /\>other configurations possible within the general category of "fan dipoles".\u003cbr /\>\u003cbr /\>Autotuner Problems with Single Wire Antenna\u003cbr /\>Autotuners have been in popular use for both amateur and non-amateur\u003cbr /\>applications, especially when many channels or bands of frequencies are\u003cbr /\>utilized throughout the HF spectrum. Problem frequencies are sometimes found\u003cbr /\>in long single-wire autotuner installations, usually due to combined RF\u003cbr /\>",1]
);
//-->
callsigns. When the distant scanning station detects the first fewcharacters of its callsign, it stops scanning and stays on that frequency.The two stations' ALE controllers automatically handshake to confirm that alink is established and they are ready to communicate. The receivingstation, which was muted up until now, will typically emit an audible alarmand visual alert for the receiving operator of the incoming call. It alsoindicates the callsign of the linked station. The operators then can talk ina regular conversation. At the conclusion of the QSO, one of the stationssends a disconnect signal to the other station, and they each return theirALE stations to the scanning mode. Some military / commercial HFtransceivers are available with ALE options. Amateur radio operatorscommonly use the PCALE soundcard software ALE controller, interfaced to aham transceiver via RS-232 CAT port, multi-frequency antenna.Multi-Frequency Antennas Systems.The Autotuner Inverted-V-Fan-Dipole and Autotuner V-Fan-DipoleDesign and Installation Notes by Bonnie Crystal KQ6XABackgroundVarious versions of multi-wire dipole antennas are known and widely used. HFinverted-V antennas called "maypole" antennas, have been utilized withdipoles resonant in the amateur bands. The most common has been the3.8MHz/7.1MHz resonant version fed with 50ohm coax. Technically, the antennasystem consists of two or more dipoles of different lengths arrangedradially in inverted-Vee form with a single common feedpoint. There areother configurations possible within the general category of "fan dipoles".Autotuner Problems with Single Wire AntennaAutotuners have been in popular use for both amateur and non-amateurapplications, especially when many channels or bands of frequencies areutilized throughout the HF spectrum. Problem frequencies are sometimes foundin long single-wire autotuner installations, usually due to combined RF
impedance presented to the autotuner. At the problem frequencies, it can\u003cbr /\>take a long time for the autotuner to repeatably find a match, or it may not\u003cbr /\>be possible for it to find an acceptable match. Other problems with the same\u003cbr /\>root cause can lead to excessive RF radiation from the feedline at the\u003cbr /\>transmitter (hot mic syndrome). Sometimes, simply changing the length of the\u003cbr /\>antenna wire slightly is sufficient to move the "problem" to an unused\u003cbr /\>frequency. But changes in the ground conductivity due to rain or other\u003cbr /\>factors can bring the problem back.\u003cbr /\>\u003cbr /\>Multiple Antenna Wires for Fast Autotuning\u003cbr /\>HF-ALE (Automatic Link Establishment) requires fast autotuner action, and\u003cbr /\>the linking functions best when the antenna matching autotuning cycle is\u003cbr /\>completed within a fraction of a second. Application of the multi-wire\u003cbr /\>dipole principle to the autotuner installation provides a solution. In\u003cbr /\>practice, it has been found that there are advantages to certain wire\u003cbr /\>lengths or wire length ratios for autotuner use in the HF spectrum. These\u003cbr /\>ratios of wire lengths present multiple "convenient" lower impedances to the\u003cbr /\>autotuner at any given frequency, enabling it to achieve a matched condition\u003cbr /\>rapidly and repeatably, thereby mitigating "problem frequencies".\u003cbr /\>\u003cbr /\>Autotuner Fan Dipoles in Use for ALE\u003cbr /\>I have developed the two successful versions of an autotuner fan dipole\u003cbr /\>antenna system shown above, through both theoretical and empirical design\u003cbr /\>(trial and error). I am presently using one of these antenna systems on the\u003cbr /\>air 24/7 for ALE, from 1.8MHz to 28MHz. I am using an SG-230 autotuner in\u003cbr /\>this installation, but the principles are the same for most of the common\u003cbr /\>autotuners of similar type.\u003cbr /\>\u003cbr /\>Common Mode Chokes\u003cbr /\>I\'ve set up 3 different SGC autotuner systems at base stations using the\u003cbr /\>common mode chokes (1:1 balun a misnomer) in the control/DC\u003cbr /\>",1]
);
//-->
reference plane (tuner ground) and wire resonance resulting in a very highimpedance presented to the autotuner. At the problem frequencies, it cantake a long time for the autotuner to repeatably find a match, or it may notbe possible for it to find an acceptable match. Other problems with the sameroot cause can lead to excessive RF radiation from the feedline at thetransmitter (hot mic syndrome). Sometimes, simply changing the length of theantenna wire slightly is sufficient to move the "problem" to an unusedfrequency. But changes in the ground conductivity due to rain or otherfactors can bring the problem back.Multiple Antenna Wires for Fast AutotuningHF-ALE (Automatic Link Establishment) requires fast autotuner action, andthe linking functions best when the antenna matching autotuning cycle iscompleted within a fraction of a second. Application of the multi-wiredipole principle to the autotuner installation provides a solution. Inpractice, it has been found that there are advantages to certain wirelengths or wire length ratios for autotuner use in the HF spectrum. Theseratios of wire lengths present multiple "convenient" lower impedances to theautotuner at any given frequency, enabling it to achieve a matched conditionrapidly and repeatably, thereby mitigating "problem frequencies".Autotuner Fan Dipoles in Use for ALEI have developed the two successful versions of an autotuner fan dipoleantenna system shown above, through both theoretical and empirical design(trial and error). I am presently using one of these antenna systems on theair 24/7 for ALE, from 1.8MHz to 28MHz. I am using an SG-230 autotuner inthis installation, but the principles are the same for most of the commonautotuners of similar type.Common Mode ChokesI've set up 3 different SGC autotuner systems at base stations using thecommon mode chokes (1:1 balun a misnomer) in the control/DC
keep some of the noise from computers and equipment in the station from\u003cbr /\>being conducted into the autotuner\'s antenna system on receive, and they\u003cbr /\>help choke off RF currents on transmit from going down the cables into the\u003cbr /\>station. In the first two of those installations, severe RFI was eliminated\u003cbr /\>that was present before the "chokes" were installed. In the third, I\u003cbr /\>installed the chokes during the initial installation, and have not removed\u003cbr /\>them to see how much difference they make.\u003cbr /\>\u003cbr /\>Grounding\u003cbr /\>Indeed, many operators are content to simply ground the coax and control\u003cbr /\>cable at the station entrance (good practice). I\'m from ye olde school of\u003cbr /\>lightning protection (having built broadcast stations and telephone central\u003cbr /\>switching offices in my earlier career), so you will see additional ground\u003cbr /\>straps present near the antenna in my base station antenna designs. I\u003cbr /\>believe that a direct lightning discharge path to earth ground is a good\u003cbr /\>design starting point for basic lightning protection. I also believe that\u003cbr /\>the possible loss in RF efficiency at some frequencies is worth trading for\u003cbr /\>the added safety that earth grounding at the antenna provides.\u003cbr /\>\u003cbr /\>Temporary Portable Installations\u003cbr /\>For temporary portable installations when no chance of lightning hazard\u003cbr /\>exists, the safety ground strap could be eliminated. The common mode chokes\u003cbr /\>and control feedline ferrites may also be eliminated if no "hot mic" RF\u003cbr /\>feedback or RFI is experienced.\u003cbr /\>\u003cbr /\>Feedback and Field Reports Requested\u003cbr /\>There are other possible combinations of wire lengths and configurations\u003cbr /\>that should function in a similar manner. I am interested in the results of\u003cbr /\>others who are using this type of antenna system or derivatives of it.\u003cbr /\>Feedback or field reports may be sent directly to the HFLINK or HFpack\u003cbr /\>groups.\u003cbr /\>\u003cbr /\>Bonnie Crystal KQ6XA\u003cbr /\>\u003cbr /\>______________________________\u003cwbr /\>_________________\u003cbr /\>CLUSTER mailing list\u003cbr /\>\u003ca onclick\u003d\"return top.js.OpenExtLink(window,event,this)\" href\u003d\"mailto:CLUSTER@radio-amador.net\"\>CLUSTER@radio-amador.net\u003c/a\>\u003cbr /\>\u003ca onclick\u003d\"return top.js.OpenExtLink(window,event,this)\" href\u003d\"http://radio-amador.net/cgi-bin/mailman/listinfo/cluster\" target\u003d_blank\>http://radio-amador.net/cgi\u003cwbr /\>-bin/mailman/listinfo/cluster\u003c/a\>\u003cbr /\>\u003cbr /\>\u003cbr /\>\u003c/div\>",0]
);
//-->
cables/feedlines, combined with a grounding strap to earth. These techniqueskeep some of the noise from computers and equipment in the station frombeing conducted into the autotuner's antenna system on receive, and theyhelp choke off RF currents on transmit from going down the cables into thestation. In the first two of those installations, severe RFI was eliminatedthat was present before the "chokes" were installed. In the third, Iinstalled the chokes during the initial installation, and have not removedthem to see how much difference they make.GroundingIndeed, many operators are content to simply ground the coax and controlcable at the station entrance (good practice). I'm from ye olde school oflightning protection (having built broadcast stations and telephone centralswitching offices in my earlier career), so you will see additional groundstraps present near the antenna in my base station antenna designs. Ibelieve that a direct lightning discharge path to earth ground is a gooddesign starting point for basic lightning protection. I also believe thatthe possible loss in RF efficiency at some frequencies is worth trading forthe added safety that earth grounding at the antenna provides.Temporary Portable InstallationsFor temporary portable installations when no chance of lightning hazardexists, the safety ground strap could be eliminated. The common mode chokesand control feedline ferrites may also be eliminated if no "hot mic" RFfeedback or RFI is experienced.Feedback and Field Reports RequestedThere are other possible combinations of wire lengths and configurationsthat should function in a similar manner. I am interested in the results ofothers who are using this type of antenna system or derivatives of it.Feedback or field reports may be sent directly to the HFLINK or HFpackgroups.Bonnie Crystal KQ6XA_______________________________________________CLUSTER mailing listCLUSTER@radio-amador.nethttp://radio-amador.net/cgi-bin/mailman/listinfo/cluster
possível estabelecer comunicações.\u003cbr /\>\u003cbr /\>O transceptor administrado pelo sistema procura constantemente e em tempo\u003cbr /\>real manter a rede interligada ou o contacto ponto a ponto sem que os\u003cbr /\>operadores tenham de procurar. Basicamente todos os transceptores que possam\u003cbr /\>ser controlados via PC podem ser usados, no entanto, existem alguns modelos\u003cbr /\>onde é mais facil a integração, exemplos:\u003cbr /\>\u003cbr /\>ICOM\u003cbr /\>IC746, IC746PRO, IC7400, IC756PRO (Milspec 1030E-DSP), IC756PRO2, IC756PRO3,\u003cbr /\>IC765, IC775, IC781, IC7800 (\u003cbr /\>\u003cbr /\>KENWOOD\u003cbr /\>All Kenwood models after, but excluding the TS-440, PA relays handled by use\u003cbr /\>of SPLIT VFO, all support up to 2 ch/sec scan rate, newer models at 9600\u003cbr /\>baud up to 5 ch/sec and those at 19,200 baud at 10 ch/sec scan rate\u003cbr /\>\u003cbr /\>YAESU\u003cbr /\>FT-920, FT-990 with SPLIT VFO (FT-890 with special QS/S modification) all\u003cbr /\>can do up to 2 ch/sec scan rate\u003cbr /\>\u003cbr /\>Neste momento a rede Global ao nível dos EUA é contituida por 6 estações\u003cbr /\>piloto automáticas trabalhando 24H e 7 dias por semana, equipadas com o\u003cbr /\>sistema de scanning ALE, Antenas multibanda e um software especial de\u003cbr /\>controlo, que pode ser comandado e acedido via Internet.\u003cbr /\>\u003cbr /\>O sistema está em expansão constante com integração de novas\u003cbr /\>funcionalidades, exemplo; msg tipo SMS aos membros enviadas da Internet,\u003cbr /\>telefone móvel ou vice-versa. Os promotores esperam alargar rapidamente este\u003cbr /\>projecto ao nível planetário.\u003cbr /\>\u003cbr /\>Os requisitos básicos são:\u003cbr /\>- Um Computador, preferencialmente portátil.\u003cbr /\>- Um transceptor.\u003cbr /\>- Um conjunto de antenas multibanda comutadas ou comandadas\u003cbr /\>automaticamente.(não pensem que é preciso ANTENAS DIRECIONAIS TIPO\u003cbr /\>LOG-PERIÓDICA, ler a explicação e conselho mais abaixo dadas pela Bonnie\u003cbr /\>Crystal-KQ6XA)\u003cbr /\>\u003cbr /\>Para mais informações podem aceder á página do HFLINK Group em:\u003cbr /\>\u003ca onclick\u003d\"return top.js.OpenExtLink(window,event,this)\" href\u003d\"http://hflink.com/\" target\u003d_blank\>",1]
);
//-->
encarregasse de seleccionar este importante parâmetro sem o qual não épossível estabelecer comunicações.O transceptor administrado pelo sistema procura constantemente e em temporeal manter a rede interligada ou o contacto ponto a ponto sem que osoperadores tenham de procurar. Basicamente todos os transceptores que possamser controlados via PC podem ser usados, no entanto, existem alguns modelosonde é mais facil a integração, exemplos:ICOMIC746, IC746PRO, IC7400, IC756PRO (Milspec 1030E-DSP), IC756PRO2, IC756PRO3,IC765, IC775, IC781, IC7800 (KENWOODAll Kenwood models after, but excluding the TS-440, PA relays handled by useof SPLIT VFO, all support up to 2 ch/sec scan rate, newer models at 9600baud up to 5 ch/sec and those at 19,200 baud at 10 ch/sec scan rateYAESUFT-920, FT-990 with SPLIT VFO (FT-890 with special QS/S modification) allcan do up to 2 ch/sec scan rateNeste momento a rede Global ao nível dos EUA é contituida por 6 estaçõespiloto automáticas trabalhando 24H e 7 dias por semana, equipadas com osistema de scanning ALE, Antenas multibanda e um software especial decontrolo, que pode ser comandado e acedido via Internet.O sistema está em expansão constante com integração de novasfuncionalidades, exemplo; msg tipo SMS aos membros enviadas da Internet,telefone móvel ou vice-versa. Os promotores esperam alargar rapidamente esteprojecto ao nível planetário.Os requisitos básicos são:- Um Computador, preferencialmente portátil.- Um transceptor.- Um conjunto de antenas multibanda comutadas ou comandadasautomaticamente.(não pensem que é preciso ANTENAS DIRECIONAIS TIPOLOG-PERIÓDICA, ler a explicação e conselho mais abaixo dadas pela BonnieCrystal-KQ6XA)Para mais informações podem aceder á página do HFLINK Group em:
.\u003cbr /\>\u003cbr /\>Entretanto, deixo-vos algumas explicações em inglês dadas pela excepcional\u003cbr /\>Amadora de Rádio norte-americana, Bonnie Crystal-KQ6XA\u003cbr /\>\u003cbr /\>João Costa\u003cbr /\>CT1FBF\u003cbr /\>\u003cbr /\>\u003cbr /\>What is ALE?\u003cbr /\>ALE is the humorous acronym for the lofty-sounding Automatic Link\u003cbr /\>Establishment. It is the de-facto worldwide standard for initiating\u003cbr /\>communications using High Frequency radio. HF radio conveys signals via\u003cbr /\>ionospheric propagation, which is a constantly changing medium. With the\u003cbr /\>capability to call up a specific station, a group of stations, a net, a\u003cbr /\>networked station, or just CQ, ALE is a versatile system for connecting\u003cbr /\>radio operators for voice, data, text, instant messaging, internet\u003cbr /\>messaging, or image communications. A radio operator initiating a call, can\u003cbr /\>within minutes have the ALE automatically pick a frequency that has a good\u003cbr /\>propagation path. It signals the operators on both ends, so they can begin\u003cbr /\>communicating with each other immediately. In this respect, it can eliminate\u003cbr /\>the longstanding need for repetitive calling on pre-determined time\u003cbr /\>schedules and monitoring static on HF radios. It is a great tool for finding\u003cbr /\>optimum ionospheric propagation between stations in real-time, while\u003cbr /\>avoiding guesswork, beacon listening, and complicated HF prediction charts\u003cbr /\>altogether. These days, ALE is most commonly used for hooking up operators\u003cbr /\>for voice communications on SSB and for internet messaging, but there are\u003cbr /\>many other useful features.\u003cbr /\>\u003cbr /\>\u003cbr /\>How ALE Works\u003cbr /\>Each radio ALE station uses a callsign or address in the ALE controller.When\u003cbr /\>not actively in communication with another station, each HF SSB transceiver\u003cbr /\>constantly scans through a list of frequencies, listening for its callsign.\u003cbr /\>To reach a specific station, the caller simply enters the callsign just like\u003cbr /\>dialing a phone number. The ALE controller selects the best available\u003cbr /\>frequency and sends out brief selective calling signals containing the\u003cbr /\>",1]
);
//-->
http://hflink.com/ .Entretanto, deixo-vos algumas explicações em inglês dadas pela excepcionalAmadora de Rádio norte-americana, Bonnie Crystal-KQ6XAJoão CostaCT1FBFWhat is ALE?ALE is the humorous acronym for the lofty-sounding Automatic LinkEstablishment. It is the de-facto worldwide standard for initiatingcommunications using High Frequency radio. HF radio conveys signals viaionospheric propagation, which is a constantly changing medium. With thecapability to call up a specific station, a group of stations, a net, anetworked station, or just CQ, ALE is a versatile system for connectingradio operators for voice, data, text, instant messaging, internetmessaging, or image communications. A radio operator initiating a call, canwithin minutes have the ALE automatically pick a frequency that has a goodpropagation path. It signals the operators on both ends, so they can begincommunicating with each other immediately. In this respect, it can eliminatethe longstanding need for repetitive calling on pre-determined timeschedules and monitoring static on HF radios. It is a great tool for findingoptimum ionospheric propagation between stations in real-time, whileavoiding guesswork, beacon listening, and complicated HF prediction chartsaltogether. These days, ALE is most commonly used for hooking up operatorsfor voice communications on SSB and for internet messaging, but there aremany other useful features.How ALE WorksEach radio ALE station uses a callsign or address in the ALE controller.Whennot actively in communication with another station, each HF SSB transceiverconstantly scans through a list of frequencies, listening for its callsign.To reach a specific station, the caller simply enters the callsign just likedialing a phone number. The ALE controller selects the best availablefrequency and sends out brief selective calling signals containing the
characters of its callsign, it stops scanning and stays on that frequency.\u003cbr /\>The two stations\' ALE controllers automatically handshake to confirm that a\u003cbr /\>link is established and they are ready to communicate. The receiving\u003cbr /\>station, which was muted up until now, will typically emit an audible alarm\u003cbr /\>and visual alert for the receiving operator of the incoming call. It also\u003cbr /\>indicates the callsign of the linked station. The operators then can talk in\u003cbr /\>a regular conversation. At the conclusion of the QSO, one of the stations\u003cbr /\>sends a disconnect signal to the other station, and they each return their\u003cbr /\>ALE stations to the scanning mode. Some military / commercial HF\u003cbr /\>transceivers are available with ALE options. Amateur radio operators\u003cbr /\>commonly use the PCALE soundcard software ALE controller, interfaced to a\u003cbr /\>ham transceiver via RS-232 CAT port, multi-frequency antenna.\u003cbr /\>\u003cbr /\>Multi-Frequency Antennas Systems.\u003cbr /\>The Autotuner Inverted-V-Fan-Dipole and Autotuner V-Fan-Dipole\u003cbr /\>Design and Installation Notes by Bonnie Crystal KQ6XA\u003cbr /\>\u003cbr /\>Background\u003cbr /\>Various versions of multi-wire dipole antennas are known and widely used. HF\u003cbr /\>inverted-V antennas called "maypole" antennas, have been utilized with\u003cbr /\>dipoles resonant in the amateur bands. The most common has been the\u003cbr /\>3.8MHz/7.1MHz resonant version fed with 50ohm coax. Technically, the antenna\u003cbr /\>system consists of two or more dipoles of different lengths arranged\u003cbr /\>radially in inverted-Vee form with a single common feedpoint. There are\u003cbr /\>other configurations possible within the general category of "fan dipoles".\u003cbr /\>\u003cbr /\>Autotuner Problems with Single Wire Antenna\u003cbr /\>Autotuners have been in popular use for both amateur and non-amateur\u003cbr /\>applications, especially when many channels or bands of frequencies are\u003cbr /\>utilized throughout the HF spectrum. Problem frequencies are sometimes found\u003cbr /\>in long single-wire autotuner installations, usually due to combined RF\u003cbr /\>",1]
);
//-->
callsigns. When the distant scanning station detects the first fewcharacters of its callsign, it stops scanning and stays on that frequency.The two stations' ALE controllers automatically handshake to confirm that alink is established and they are ready to communicate. The receivingstation, which was muted up until now, will typically emit an audible alarmand visual alert for the receiving operator of the incoming call. It alsoindicates the callsign of the linked station. The operators then can talk ina regular conversation. At the conclusion of the QSO, one of the stationssends a disconnect signal to the other station, and they each return theirALE stations to the scanning mode. Some military / commercial HFtransceivers are available with ALE options. Amateur radio operatorscommonly use the PCALE soundcard software ALE controller, interfaced to aham transceiver via RS-232 CAT port, multi-frequency antenna.Multi-Frequency Antennas Systems.The Autotuner Inverted-V-Fan-Dipole and Autotuner V-Fan-DipoleDesign and Installation Notes by Bonnie Crystal KQ6XABackgroundVarious versions of multi-wire dipole antennas are known and widely used. HFinverted-V antennas called "maypole" antennas, have been utilized withdipoles resonant in the amateur bands. The most common has been the3.8MHz/7.1MHz resonant version fed with 50ohm coax. Technically, the antennasystem consists of two or more dipoles of different lengths arrangedradially in inverted-Vee form with a single common feedpoint. There areother configurations possible within the general category of "fan dipoles".Autotuner Problems with Single Wire AntennaAutotuners have been in popular use for both amateur and non-amateurapplications, especially when many channels or bands of frequencies areutilized throughout the HF spectrum. Problem frequencies are sometimes foundin long single-wire autotuner installations, usually due to combined RF
impedance presented to the autotuner. At the problem frequencies, it can\u003cbr /\>take a long time for the autotuner to repeatably find a match, or it may not\u003cbr /\>be possible for it to find an acceptable match. Other problems with the same\u003cbr /\>root cause can lead to excessive RF radiation from the feedline at the\u003cbr /\>transmitter (hot mic syndrome). Sometimes, simply changing the length of the\u003cbr /\>antenna wire slightly is sufficient to move the "problem" to an unused\u003cbr /\>frequency. But changes in the ground conductivity due to rain or other\u003cbr /\>factors can bring the problem back.\u003cbr /\>\u003cbr /\>Multiple Antenna Wires for Fast Autotuning\u003cbr /\>HF-ALE (Automatic Link Establishment) requires fast autotuner action, and\u003cbr /\>the linking functions best when the antenna matching autotuning cycle is\u003cbr /\>completed within a fraction of a second. Application of the multi-wire\u003cbr /\>dipole principle to the autotuner installation provides a solution. In\u003cbr /\>practice, it has been found that there are advantages to certain wire\u003cbr /\>lengths or wire length ratios for autotuner use in the HF spectrum. These\u003cbr /\>ratios of wire lengths present multiple "convenient" lower impedances to the\u003cbr /\>autotuner at any given frequency, enabling it to achieve a matched condition\u003cbr /\>rapidly and repeatably, thereby mitigating "problem frequencies".\u003cbr /\>\u003cbr /\>Autotuner Fan Dipoles in Use for ALE\u003cbr /\>I have developed the two successful versions of an autotuner fan dipole\u003cbr /\>antenna system shown above, through both theoretical and empirical design\u003cbr /\>(trial and error). I am presently using one of these antenna systems on the\u003cbr /\>air 24/7 for ALE, from 1.8MHz to 28MHz. I am using an SG-230 autotuner in\u003cbr /\>this installation, but the principles are the same for most of the common\u003cbr /\>autotuners of similar type.\u003cbr /\>\u003cbr /\>Common Mode Chokes\u003cbr /\>I\'ve set up 3 different SGC autotuner systems at base stations using the\u003cbr /\>common mode chokes (1:1 balun a misnomer) in the control/DC\u003cbr /\>",1]
);
//-->
reference plane (tuner ground) and wire resonance resulting in a very highimpedance presented to the autotuner. At the problem frequencies, it cantake a long time for the autotuner to repeatably find a match, or it may notbe possible for it to find an acceptable match. Other problems with the sameroot cause can lead to excessive RF radiation from the feedline at thetransmitter (hot mic syndrome). Sometimes, simply changing the length of theantenna wire slightly is sufficient to move the "problem" to an unusedfrequency. But changes in the ground conductivity due to rain or otherfactors can bring the problem back.Multiple Antenna Wires for Fast AutotuningHF-ALE (Automatic Link Establishment) requires fast autotuner action, andthe linking functions best when the antenna matching autotuning cycle iscompleted within a fraction of a second. Application of the multi-wiredipole principle to the autotuner installation provides a solution. Inpractice, it has been found that there are advantages to certain wirelengths or wire length ratios for autotuner use in the HF spectrum. Theseratios of wire lengths present multiple "convenient" lower impedances to theautotuner at any given frequency, enabling it to achieve a matched conditionrapidly and repeatably, thereby mitigating "problem frequencies".Autotuner Fan Dipoles in Use for ALEI have developed the two successful versions of an autotuner fan dipoleantenna system shown above, through both theoretical and empirical design(trial and error). I am presently using one of these antenna systems on theair 24/7 for ALE, from 1.8MHz to 28MHz. I am using an SG-230 autotuner inthis installation, but the principles are the same for most of the commonautotuners of similar type.Common Mode ChokesI've set up 3 different SGC autotuner systems at base stations using thecommon mode chokes (1:1 balun a misnomer) in the control/DC
keep some of the noise from computers and equipment in the station from\u003cbr /\>being conducted into the autotuner\'s antenna system on receive, and they\u003cbr /\>help choke off RF currents on transmit from going down the cables into the\u003cbr /\>station. In the first two of those installations, severe RFI was eliminated\u003cbr /\>that was present before the "chokes" were installed. In the third, I\u003cbr /\>installed the chokes during the initial installation, and have not removed\u003cbr /\>them to see how much difference they make.\u003cbr /\>\u003cbr /\>Grounding\u003cbr /\>Indeed, many operators are content to simply ground the coax and control\u003cbr /\>cable at the station entrance (good practice). I\'m from ye olde school of\u003cbr /\>lightning protection (having built broadcast stations and telephone central\u003cbr /\>switching offices in my earlier career), so you will see additional ground\u003cbr /\>straps present near the antenna in my base station antenna designs. I\u003cbr /\>believe that a direct lightning discharge path to earth ground is a good\u003cbr /\>design starting point for basic lightning protection. I also believe that\u003cbr /\>the possible loss in RF efficiency at some frequencies is worth trading for\u003cbr /\>the added safety that earth grounding at the antenna provides.\u003cbr /\>\u003cbr /\>Temporary Portable Installations\u003cbr /\>For temporary portable installations when no chance of lightning hazard\u003cbr /\>exists, the safety ground strap could be eliminated. The common mode chokes\u003cbr /\>and control feedline ferrites may also be eliminated if no "hot mic" RF\u003cbr /\>feedback or RFI is experienced.\u003cbr /\>\u003cbr /\>Feedback and Field Reports Requested\u003cbr /\>There are other possible combinations of wire lengths and configurations\u003cbr /\>that should function in a similar manner. I am interested in the results of\u003cbr /\>others who are using this type of antenna system or derivatives of it.\u003cbr /\>Feedback or field reports may be sent directly to the HFLINK or HFpack\u003cbr /\>groups.\u003cbr /\>\u003cbr /\>Bonnie Crystal KQ6XA\u003cbr /\>\u003cbr /\>______________________________\u003cwbr /\>_________________\u003cbr /\>CLUSTER mailing list\u003cbr /\>\u003ca onclick\u003d\"return top.js.OpenExtLink(window,event,this)\" href\u003d\"mailto:CLUSTER@radio-amador.net\"\>CLUSTER@radio-amador.net\u003c/a\>\u003cbr /\>\u003ca onclick\u003d\"return top.js.OpenExtLink(window,event,this)\" href\u003d\"http://radio-amador.net/cgi-bin/mailman/listinfo/cluster\" target\u003d_blank\>http://radio-amador.net/cgi\u003cwbr /\>-bin/mailman/listinfo/cluster\u003c/a\>\u003cbr /\>\u003cbr /\>\u003cbr /\>\u003c/div\>",0]
);
//-->
cables/feedlines, combined with a grounding strap to earth. These techniqueskeep some of the noise from computers and equipment in the station frombeing conducted into the autotuner's antenna system on receive, and theyhelp choke off RF currents on transmit from going down the cables into thestation. In the first two of those installations, severe RFI was eliminatedthat was present before the "chokes" were installed. In the third, Iinstalled the chokes during the initial installation, and have not removedthem to see how much difference they make.GroundingIndeed, many operators are content to simply ground the coax and controlcable at the station entrance (good practice). I'm from ye olde school oflightning protection (having built broadcast stations and telephone centralswitching offices in my earlier career), so you will see additional groundstraps present near the antenna in my base station antenna designs. Ibelieve that a direct lightning discharge path to earth ground is a gooddesign starting point for basic lightning protection. I also believe thatthe possible loss in RF efficiency at some frequencies is worth trading forthe added safety that earth grounding at the antenna provides.Temporary Portable InstallationsFor temporary portable installations when no chance of lightning hazardexists, the safety ground strap could be eliminated. The common mode chokesand control feedline ferrites may also be eliminated if no "hot mic" RFfeedback or RFI is experienced.Feedback and Field Reports RequestedThere are other possible combinations of wire lengths and configurationsthat should function in a similar manner. I am interested in the results ofothers who are using this type of antenna system or derivatives of it.Feedback or field reports may be sent directly to the HFLINK or HFpackgroups.Bonnie Crystal KQ6XA_______________________________________________CLUSTER mailing listCLUSTER@radio-amador.nethttp://radio-amador.net/cgi-bin/mailman/listinfo/cluster
Labels: hf, radio emergência, radioamadores
posted by a d´almeida nunes @ 10:17 AM
2 comments
