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Details the construction and optimization of antenna systems for amateur radio satellite operations, focusing on practical, homebrew solutions for VHF/UHF bands. It covers building _groundplane antennas_ from salvaged materials, recycling old beam antennas into new configurations like a 2-meter crossed yagi, and constructing a 10-meter horizontal delta loop. The resource also explains antenna matching techniques, including folded dipole driven elements and quarter-wave transformers, along with the importance of accurate SWR measurements and minimizing coax loss. Demonstrates how to achieve a **1:1 SWR** by carefully trimming elements and adjusting radial angles on groundplane antennas. It provides insights into selecting appropriate coax and connectors, highlighting the benefits of Belden 9913 for low loss and the proper installation of _N-connectors_. The article also addresses RFI mitigation from computer birdies and presents a design for a silent triac antenna control circuit, offering practical solutions for common satellite station challenges.

Orbitron, a cardware application, provides robust satellite tracking capabilities for radio amateurs and visual observers alike. It leverages NORAD SGP4/SDP4 prediction models to accurately display satellite positions in real-time or simulation, accommodating up to 20,000 objects loaded from _TLE files_. The software includes an advanced search engine for satellite passes and _Iridium flares_, offering printable results for planning observations or QSO attempts. Sebastian Stoff's creation supports various visualization options, including a 'Nightlife' dark color scheme for nocturnal use, and integrates a database of cities and satellite frequencies. Users can synchronize their PC clock via NTP and update TLE data over HTTP, with ZIP support. The application also features rotor and radio control capabilities, either built-in or through user-defined drivers, which is particularly useful for automating antenna pointing during satellite passes. Its interface is designed for ease of use, making satellite tracking accessible even for beginners. First released in 2005, Orbitron 3.71 runs on Windows 9x/Me/2k/XP/2k3/Vista and can operate on Linux via _Wine emulation_, requiring minimal system resources. The software's precision relies on periodic TLE updates, especially for low-Earth orbit objects, to account for orbital decay and maneuvers by satellites like the ISS or Soyuz.

Presents a Brazilian online portal dedicated to **amateur radio**, **CB radio**, and shortwave listening (SWL) communities. The platform facilitates free classified advertisements for radio equipment, including HF, VHF, and UHF transceivers, antennas, and accessories. It also aggregates a substantial collection of technical articles from Brazilian amateur radio operators (e.g., PY2DJW, PY1LJ, PY1LL/4LC), covering topics such as CW training with RufzXP, balun importance, and radio wave characteristics. Furthermore, the resource provides extensive links to Brazilian ham radio sites, clubs, international organizations, and official ANATEL (Brazilian National Telecommunications Agency) documents regarding licensing, equipment homologation, and regulations. The portal features sections for user evaluations of transactions, a "Top Ten" list of most visited pages, and a calendar of past and upcoming ham radio events across Brazil, including "Feirinhas" (local swap meets) and "Encontros de Radioamadores" (hamfests). It also includes a directory of ham radio related businesses and services in Brazil, such as antenna manufacturers (Diex), QSL card printers (Arte Final), and repair technicians (PY2MOK). The site also offers propagation maps, DX cluster links (e.g., DX-SUMMIT), and satellite tracking tools, making it a central hub for Brazilian radio amateurs seeking to buy, sell, learn, or connect with the community.