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Query: 1 to 2 balun
Links: 253 | Categories: 4
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This project describes a high-performance EME antenna array consisting of two home-designed 9-element Yagis, each about 2.5 wavelengths long, combined into a 25-ohm system and matched to 100 ohms using 9/4λ sections of 50-ohm coax. The array supports rotatable polarity from 0° to 180°, allowing both horizontal and vertical polarization to optimize moonbounce performance under varying conditions. Despite operating for years without a balun—something another designer called “disastrousâ€â€”the system has delivered strong results, including copying very weak DX such as VK3KH at about -25 dB with only 120 W (around 2 kW ERP). The builder continues to refine the mechanics, having installed new gear motors and an upgraded follow-up control system in 2011.
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Demonstrates the design and modeling of a **160m** vertical antenna, dubbed the "WindoVert," specifically for urban amateur radio operators with limited space. The resource covers the theoretical underpinnings of antenna height and radiation patterns, using EZNEC software to analyze current distribution and 3D radiation patterns for various configurations, including a Marconi-style "T" antenna. It details the integration of existing antenna components, such as a Carolina Windom balun and line isolator, into the new vertical setup, and the practical measurement of feedpoint impedance using an antenna analyzer. The article further explores the challenges of achieving low-angle radiation on Top Band, emphasizing the critical role of radial systems and mitigating ground loss. Author VE1ZAC presents EZNEC models illustrating the impact of lumped components and discusses the practical considerations of resonant frequency adjustment and impedance matching for **QRP** operation. The text details the calculation of required loading coil inductance and capacitance, and shares field results, including successful DX contacts on 160m and unexpected excellent performance on 30m.
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The Ham Shop is an authorized dealer for ham radio accessories and equipment from manufacturers including MFJ, Ameritron, Cushcraft, HyGain, and DacRope. The inventory includes antennas, cables, coax wire, and specific products like Signalink interfaces. Available antenna types encompass support rope (e.g., 3/16" Dacron Polyester Rope), switches, and tuners. Additional station accessories include baluns, dummy loads, duplexers, insulators, microphones, power supplies, SWR meters, test instruments, and watt meters. The product range supports various amateur radio operations, offering components for station setup and maintenance across different frequency bands. Examples include the _MFJ-915_ RF Isolator, rated for 1.8-30 MHz and **1500W PEP**.