AMSAT-OSCAR 51 or AO-51 is the in-orbit name designation of a now defunct (following battery failure) LEO amateur radio satellite of the OSCAR series; formerly known as ECHO, built by AMSAT. It was launched on June 29, 2004 from Baikonur Cosmodrome, Kazakhstan on a Dnepr launch vehicle. It is in Sun synchronous low Earth orbit.

AO-51 has four VHF receivers and two UHF transmitters, one multi-mode receiver and a 2.4 GHz transmitter. It orbits the Earth in a high 850KM, sun synchronic orbit. The inclination is 98.2 °. With four VHF receivers, two UHF transmitters, six modems, fifty-six channels of telemetry, and various other subsystems AO-51 is quite a complex spacecraft.

USS Ashtabula (AO-51) was a Cimarron-class fleet oiler of the United States Navy in service from 1943 to 1991. She survived three wars and was awarded eight battle stars for World War II service, four battle stars for Korean War service, and …

AO-51 is currently transmitting on: Downlink: 435.150 MHz FM (LHCP) and using a Uplink: 145.880 MHz FM. The power level is just under 1 watt (about 980 mW). Controllers expect to keep this configuration until further notice. Keep up with the latest AO-51 Control Team News on-line at: http://www.amsat.org/amsat-new/echo/CTNews.php

2004年6月29日 · AO-51 is the in-orbit name designation of a now defunct (following battery failure) LEO amateur radio satellite of the OSCAR series; formerly known as ECHO, built by AMSAT. It was launched on June 29, 2004 from Baikonur Cosmodrome, Kazakhstan on …

2025年3月1日 · Amsat-Echo, also known as AMSAT Oscar-E or AO-51, is an American amateur communications microsatellite satellite (10 kg) that relays amateur transmissions. AO-51 contains an FM repeater with both a 144 MHz and 1.2 GHz uplink and 435 MHz and 2.4 GHz downlinks.

AO-51搭载有不同类型的转发器，本文将以调频语音转发器为例，指导初学者进行业余卫星通信。 业余卫星运行早期，常用一个或几个字母来表示卫星转发器的模式。

2021年1月23日 · 图 1 Phase 3-B （ AO-10 ），是迄今 为止 AMSAT 最成功的配备线性转发器的高轨业余卫星。 它为全球用户提供了长时远距业余卫星通联服务。 悬挂于科鲁乌发射场 （ AMSAT-DL 提供）

2011年11月26日 · AMSAT-NA VP Operations Drew Glasbrenner KO4MA reports on Friday's IHU crash on the Amateur Radio satellite AO-51. Sometime between 1815 and 1945Z November 25, AO-51's IHU crashed. This happened after a few days of intermittent and unpredictable operation.

2013年2月9日 · AO-51又名ECHO，是AMSAT-NA研制的一颗业余卫星。 其概况如下： 业余无线电转发器是该卫星的主要载荷。 可使用语音或PACSAT BBS模式工作。 ECHO-----------EHCO,E版是无线电吗？ 貌似是虎哥吧. 11KG麻雀卫星······！ 蓝色的盒子是UHF功率分配器，两个银色盒子是UHF发射机。 多波段接收机在功率分配器下面，10m, 2m, 70cm and 23cm 全模式。 UHF发射机内部。 1~6 W输出，步进2.5 kHz，调谐范围20 MHz. The AO-51 Control Team reports AO …