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<body class='hmmessage'><div dir='ltr'><b><font face="Verdana" color="#5133ab">Prezado João Costa e colegas radioamadores em geral</font></b><div><b><font face="Verdana" color="#5133ab"><br></font></b></div><div><b><font face="Verdana" color="#5133ab">Aqui do Portugal profundo onde o vento uiva e a chuva e neve acompanham, d<span style="font-size: 12pt;">esejo a todos sem excepção um Feliz Natal e que o Novo Ano vos traga o que desejam.</span></font></b></div><div><span style="font-size: 12pt;"><b><font face="Verdana" color="#5133ab">Estes os votos do CT1DDW e QRA.</font></b></span></div><div><span style="font-size: 12pt;"><b><font face="Verdana" color="#5133ab"><br></font></b></span></div><div><span style="font-size: 12pt;"><b><font face="Verdana" color="#5133ab">Filipe Ferreira</font></b></span></div><div><span style="font-size: 12pt;"><br></span></div><div><span style="font-size: 12pt;"><br></span></div><div><span style="font-size: 12pt;"> </span></div><div><br><div>Date: Mon, 23 Dec 2013 21:05:39 +0000<br>From: ct1fbf@gmail.com<br>To: cluster@radio-amador.net<br>Subject: ARLA/CLUSTER: Recomendações da IARU para a Região 3<br><br><pre> IARU Recommendations<br> <br>Dear Colleagues,<br> <br>I should have sent out this notice much earlier, but please note the<br>recommendation below which has been agreed at the Region 3 Directors<br>meeting in Tokyo, August 2013.<br> <br><Quote><br> <br>At the Region 3 Directors meeting held in August 26th and 27th, 2013,<br>the following two recommendations were adopted regarding usage of two<br>meter band for the amateur satellite service.<br> <br>1. It is recommended that the band 144-146 MHz (“two-meter” band) be<br>used exclusively for down link on all future satellites.<br> <br>2. It is recommended that the 144.000-144.035 MHz section be<br>additionally allocated for satellite down link .<br> <br>Background information<br> <br>1. Usage of the band 144-146 MHz for down link only<br> <br>The band 144-146 MHz (“two-meter” band) is, according to the Radio<br>Regulations, allocated to the amateur and the amateur-satellite<br>services world-wide on a primary basis with exceptions in several<br>footnotes. But by agreement of all three IARU Regions, currently only<br>a sub-section, namely 145.80–146 MHz of the allocation, is used on an<br>exclusive basis for the amateur-satellite service.<br> <br>Although the band 145.80 – 146 MHz is presently used for both uplink<br>and downlink portions, the Cavtat Conference of IARU Region 1 in 2008<br>agrees to recommend its use for downlink-only to reduce interference<br>signals from non-amateur signals (illegal’s like taxis) being relayed<br>if it is used for uplinks.<br> <br>The usage of the band 145.8 - 146 MHz reduces path losses by about 9dB<br>compared with usage of the band 435 - 438 MHz.<br> <br>Most amateur satellites do not employ attitude control due to their<br>size and financial constraints, therefore the use of simple<br>omni-directional antenna would be popular. In this situation 9 dB pass<br>loss advantage is essential.<br> <br>On the other hand, some societies in Region 3 have mentioned that to<br>avoid interference signals from non-amateur signals (illegal’s like<br>taxis) the band 145.8 – 146 MHz has not been used for downlinks in<br>most amateur-satellite services. But comparing effects of interference<br>caused by illegal signals on uplinks and downlinks, to avoid uplink<br>interference is important because many amateur satellites would be<br>affected if there is interference on uplink.<br> <br>Taking into account these factors mentioned above, it is recommended<br>that the band 145.8 - 146 MHz should be used for downlink only in<br>Region 3.<br> <br>2. Additional allocation of 144.000-144.035 MHz section for satellite<br>down link only<br> <br>The IARU Satellite Advisory Group has been discussing the additional<br>allocation of the 144.000-144.035 MHz section for satellite down link<br>only taking into account the shortage of spectrum of 2m band for the<br>amateur satellite service .<br> <br>In 2008 it appeared that very little EME was then taking place at the<br>very bottom of the 144 MHz band, due to interference from computer<br>oscillators. This section is already aligned worldwide and therefore<br>it was considered that this could be suitable part of the band to be<br>used.<br> <br>More recent research and discussions suggested that this situation<br>remains the same today. Further research has concluded that the bottom<br>35% of the 2 metre band is almost completely unused.<br> <br>It was noted that Region 1 had also discussed this matter and their<br>opinion was on similar lines.<br> <br>This subject was also discussed at the Region 2 conference in<br>September this year and approved.<br> <br><unquote><br> <br>73 de Ken Yamamoto, JA1CJP<br>Secretary, IARU Region 3<br>secretary<at>iaru-r3.org<br> <br>via NZART<br> <br></pre><br>_______________________________________________
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