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Query: ht antenna
Links: 3924 | Categories: 5
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A magnetic loop antenna calculator made with an excel sheet that run also with open office, let you design mag loop antenna dimensions by AA5TB
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An invisible magnetic loop antenna mounted under a table by PY1AHD
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Build your own multi-band mobile ham antenna with a Hamstick
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A QRP 900 grams hydraulic tuned small magnetic loop antenna by PY1AHD Alex.
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A delta loop antenna for 6 meters band with SWR diagram , construction plan and some pictures by IZ8EWD in Italian
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Presents a detailed construction guide for a **Quadrifilar Helix Antenna** (QHA) optimized for 137 MHz, specifically for receiving weather satellite transmissions. The resource outlines the author's experience building previous QHA designs, highlighting challenges with tuning and nulls, and then focuses on a refined design by John Boyer, documented by Steve Blackmore, which proved easier to build and yielded superior reception. The guide provides precise element dimensions, including 1.5m of 32mm PVC pipe for the mast and 8mm soft copper tubing for the helix elements. It specifies lengths for horizontal tubes (190mm, 90mm) and helix elements (903mm, 1002mm), along with instructions for drilling, assembly, and forming a **balun** by wrapping RG58 coax around the mast. The text emphasizes critical steps like ensuring elements are square and twisting in the correct direction to avoid phase issues. It includes references to original QST articles by Buck Ruperto (W3KH) and the WxSat program for decoding satellite transmissions, contextualizing the antenna's purpose. The article concludes with a sample NOAA 12 image from September 1998, demonstrating the antenna's reception capabilities.
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A magnetic loop made just of wire. Suitable for portable usage and for QRP operations.
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An efficient 2 meter antenna disguised as a TV Satellite dish. This vertically polarized horizontal slot antenna, cut into the reflector of a TV dish, might be the ultimate stealth antenna.
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Calculate Cable Loss from SWR and reverse. Text file with only two simply formulas
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Gamma match antenna is an antenna 1/2 additional lambda with the impedance matching more flexible arrangements (var capacitor) by sliding through the gamma match/road.
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Article on radiation patterns of small loops, equivalent circuits of loop antenna, small loops as receiving antennas, ferrite loops
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This project is an attempt to build a portable standalone VNA (Vector Network Analyzer).
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Calculate design for a quadrifilar helicoidal antenna
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This resource details the conversion of an 80m elevated vertical antenna to include 160m operation, focusing on a relay-switched design over a trap-based approach. It presents specific feedpoint impedance values, such as **32 ohms** for 80m and **14 ohms** for 160m, and discusses the challenges of SWR drift encountered with the prior trap system during RTTY contesting. The article thoroughly explains the design choices for elevated radials, referencing _N6LF QEX data_ to debunk common myths regarding radial length and height, demonstrating that non-resonant radials can offer superior current uniformity. The construction section provides practical insights into building the vertical, including guying strategies, material selection from scrap pipe, and weatherproofing the relay assembly. It highlights the use of a common mode choke for the relay switching line, measuring approximately 5K ohms on both 160m and 80m, and details the L/C matching network's role in achieving a 50-ohm match at the end of a 300-foot RG-11 run. The author describes a precise VNA-based radial trimming procedure, achieving resonant values within a 3 KHz range. The content emphasizes the practical application of theoretical antenna principles, particularly concerning the interaction between the vertical element, cap hats, and the matching network. It offers a candid assessment of component selection, such as using junkbox parts and acknowledging the need for future upgrades to static drain resistors. The article serves as a comprehensive case study for advanced antenna builders tackling multi-band vertical designs.
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G3TXQ pages focuses on understanding the HexBeam antennas. Basics, dimensions, multi band issues, antenna modeling.
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Demonstrates the design and construction of a 9-element Yagi antenna for the **70 cm band** (432 MHz), based on the DK7ZB concept. The resource details EZNEC+ calculations for a single antenna, providing gain, sidelobe suppression, and front-to-back ratio figures. It also presents a comprehensive analysis of stacking two such antennas, including optimal stacking distance (1000 mm) and the resulting performance enhancements for the stacked array, such as an increased gain of 17.03 dBi. The article includes detailed drawings, wire file dimensions in millimeters, and azimuth/elevation plots for both single and stacked configurations. Practical construction steps are documented with original photographs, illustrating element mounting, the **28 Ohm matching system** using two quarter-wave 75 Ohm transmission lines, and the critical N-connector wiring. It also covers the iterative process of fine-tuning the driven element length to achieve a return loss of 20 dB, validating the EZNEC+ simulation results with actual measurements.
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Remotely controlled antenna switch that can switch between 5 antennas
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VA3EXT 5 element beam antenna for 6 meters band
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Excel spreadsheet that help calculating dimensions of a high efficiency magnetic loop antenna for HF bands. Giving in input the loop perimeter, loop diameter and loop conductor will calculate electric characteristics, bandwidth, and efficiency
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Choosing the right antenna for you, by Lewis G. McCoy W1ICP
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Here is a way to ease assembly and balancing of a large antenna. The elements and boom are assembled separately in most cases. Once they are all together set up 2 tripods in the assembly area and put the boom on them.
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A Low -Power, Distributed Capacitance Twisted Loop , indoor portable HF antenna by Monty Northrup, N5ESE
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W3DZZ trapped multi-band antenna, exposed in this practical wireless article
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An 85ft wire fed against a 17ft counterpoise that works well in 80 and 40 meters
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Simple, easy to build, low cost, compact, multiband By Robert Wilson, AL7KK
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AOR USA Web site, manufacturer of base and mobile receivers, handheld receivers, digital voice modems, spectrum display units, frequency monitors and antennas
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This magnetic loop is 78cm diameter, with the smaller Hertz loop for tuning. Feeding is by gamma match.
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This group has been created to promote discussion relating to the EH Antenna. There should be many with experience with the EH Antenna, so don't be shy about asking questions on construction and efficiency.
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A 2,4 GHz 13cm band quadrible qiad antenna with reflector offering a 14dbd gain
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Cal-av labs, inc. (formerly california avionics laboratories, inc.) manufactures electronic instruments and systems for research and industry. we specialize in radio communications and research/electronic test products. Amateur radio yagi antennas, rotary dipoles, baluns, morse keys.
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Very compact and high efficiency antenna ,very low radiation angle even at low height.
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Antenne Cadre Project by F5NGZ, description by F5TZA in french
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A multiband dipole antenna that can work on 15 20 and 40 meters band made with common materials
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W3EDP multiband wire antenna, an extensive study and analysis of this antenna by W0ESE
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A simple quarter-wave length vertical for 40m band using a 12 m spiderpole
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This vertical antenna consist of a 18 meters telescopic pole and allow operations from 160 to 30 meters band, project by Daniel Zimmerman N3OX
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This receive only loop covers a frequency range of about 5 MHz to 22 MHz and is built from readily available parts.
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Plans and drawings of common amateur radio antennas, like jpoles, copper cactus, super jpole, omnidirectionals and quads
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This article describes a loop usable from 7 - 21 mHz, using half inch copper tube 3 feet in circumference
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Anyone attempting to work DX on Top-Band 160 Meters, soon learns of the need for a good receiving antenna. This is a 160 meter 8 element receiving array.
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