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Make your own VHF/UHF folded dipoles from aluminium tubing. Learn tips for folding yagi, softening the tubing, bending jig and make all waterproofing

Calculations for determining the wind loading stress on an antenna mast. Link to a spreadsheet for calculating the mast bending stress based on wind speed and antenna cross sectional area.

This wire-beam has one radiator-element, feeded with 450-Ohm-Wireman-twinlead and needs an antenna-tuner. For the bands 6m, 10m, 12m, 15m, 17m and 20m bended reflector-elements are used. The support is a cross of 4 fibreglass-fishing-rods

Fold, bend, and mutilate or kaking a dipole fit the space available

Constructing a linear focus parabolic antenna for WiFi operation involves precise metalwork, as detailed in this project. The author, AB9IL, shares a build that can be completed in a few hours, emphasizing the hands-on process of shaping and assembling metal components. This design aims to provide enhanced signal range for 2.4 GHz wireless networks, a common challenge in many ham shacks and home setups. The project outlines the practical steps required, from initial measurements to the final assembly, including cutting, bending, and bolting various metal parts. While specific gain figures are not provided, the parabolic design inherently offers significant _directional gain_ compared to omnidirectional antennas, making it suitable for point-to-point links or extending network coverage over distances. The construction process focuses on readily available materials and basic shop tools, aligning with the DIY spirit prevalent in amateur radio. This antenna project is presented as a straightforward build, requiring attention to detail in fabrication to achieve optimal performance.

The document details the optimization and construction of the _Maria Maluca_ antenna, a compact 6-band (20m-6m) directional beam. It presents a comparative analysis of shortwave antenna principles, highlighting the efficiency gains achieved by using an open feeder line and tuner as a resonant unit, contrasting this with the losses associated with traps or capacitive loads in multiband antennas. The resource specifically revisits an older South American 2-element design for 10, 15, and 20 meters, applying modern NEC-based software to develop a six-band version. Performance data is meticulously tabulated, showing impedance, free space gain, gain at 12m height, elevation angle, and front-to-back (F/B) ratio for each band from 20m through 6m. For instance, on 15m, the antenna achieves 5.1 dBd free space gain and 13.72 dB F/B ratio. The construction section provides practical guidance on element assembly using aluminum pipes and hose clamps, detailing the use of a heavy-duty glass fiber reinforced polyamide rod for electrical separation and bending strength. It also specifies the use of 450-ohm _Wireman_ line CQ 552 for the transmission line. The document includes diagrams for rod fixing, an air-wound balun, and a vertical elevation diagram for the 15m band, illustrating its DX qualification. It also discusses the antenna's suitability for portable and expedition operations, noting its compact transport dimensions (max 1.50m length, 12 lb weight) and quick assembly time (under 15 minutes). The author, Dipl.Ing. Helmut Oeller, DC6NY, is identified as a source for material kits.

Commercial interactive radio control software tun under Windows Controls up to 16 Devices simultaneously with audio, in a client server mode, support for WAVECOM decoders and ROHDE & SCHWARZ receivers

Bob's Electronics serve a wide market of customers throughout the Midwes, supports brand names such as Bendix King, ICOM, Relm, Uniden, Antenna Specialist, Antennex, Cushcraft, DB Products, Maxrad, Sinclair, and numerous others.

World Harvest Radio - South Bend, U.S.A.

The club was formed at a meeting of a group of hams on a May 1989 afternoon at Jake's Truck Stop in Bend.

A 38-foot Tristao Tower, similar to the U.S. Tower HDX538, was installed twice by the author, first in 1980 and then reinstalled in 1989. The resource details the challenges of self-performing heavy construction tasks like breaking concrete and digging a 3' x 3' x 6' deep footing, contrasting it with hiring professionals for the second installation. It highlights the financial and physical costs associated with DIY tower foundation work, noting a rebar cage cost of $65 in 1980 versus $150-$175 today, and the expense of tools for bending rebar. The content emphasizes the critical importance of obtaining building permits, recounting how a permit in Buena Park, California, nullified a neighbor's complaint about TVI. It also discusses the necessity of adhering to local building codes, such as the 1975 UBC and the subsequent 1985 UBC recertification requirement, which reduced the allowed antenna wind loading from 30 square feet to 20 square feet for the author's _KT34A_ Yagi. The footing depth also increased from 6 feet to 6.5 feet under the newer code. Practical advice includes hiring licensed contractors for specialized work, delaying antenna installation for a month after raising the tower, and verifying buried utilities before any excavation. The author provides specific examples of utility location services like _DigAlert_ in California, underscoring the legal and safety implications of neglecting this step. The narrative is grounded in personal experience, offering a realistic perspective on tower projects.

Demonstrates MegaPhase's extensive product line of RF and microwave coaxial cable assemblies and components, engineered for demanding applications up to 110 GHz. Key offerings include _Test & Measurement Cables_ with superior phase and amplitude stability, _RF & Microwave Cables_ utilizing _GrooveTube®_ technology for high power systems, and a range of RF components like directional couplers and power dividers. The site details specific cable types such as _Alumibend™_ for space-qualified, ultra-light applications through 90 GHz, and armored cables designed for rigorous environments up to 50 GHz, emphasizing their robust mechanical strength and measurement repeatability. The resource highlights applications across diverse sectors, including space programs like the _Hayabusa_ mission, global security (C5ISR), military airborne systems (MIL-T-81490), telecom, and automated testing. It also provides technical insights through "How To" guides on measuring amplitude/phase stability vs. flexure and proper connector cleaning. The company's commitment to quality is underscored by its rigorous testing protocols and a strong warranty, ensuring reliable operation in critical systems.

The areas noted in the forecast have the necessary atmospheric conditions to produce tropospheric bending of VHF, UHF and/or microwave radio waves. Tropospheric bending extends the range of radio & TV stations well beyond their normal limit and thus increases interference amongst stations as well.

You can bend the wires in a half-wave dipole so that it takes up less space, with minimal loss of efficiency.It is advisable to get the ends of the antenna as high as possible, especially if children and animals are kept in the area around the antenna, as there are very high tensions on the ends of the antenna during transmission! In Norwegian

This project involves constructing a dual-band Moxon antenna, optimized for ham radio enthusiasts, with functionality on both the 10-meter and 6-meter bands. The antenna is designed to operate using a single 50-ohm feedpoint, acting as a mini-beam on 28 MHz (10 meters) and as a 2-element Yagi on 50 MHz (6 meters). Performance-wise, it offers a 4.0 dBd gain on 10 meters and 4.3 dBd on 6 meters, with impressive front-to-back ratios of 30 dB and 11 dB, respectively. Builders like Aleks (S54S) and Marcio (PY2OK) have successfully brought this design to life using the provided specifications. Aleks noted that bending the corners of the structure proved especially useful during assembly. The project comes with a detailed parts list, highlighting the use of aluminum tubes with different diameters and lengths to form essential components like the reflectors and radiators. For those looking to fine-tune the antenna, adjustments can be made by altering the length of certain parts that fit into larger tubes. The feeding system is equipped with a balun to accommodate different power levels, making the design versatile enough to handle outputs of either 300 watts or 1 kilowatt.

The behavior of a straight dipole and its L-form is examined in terms of impedance and SWR. By adjusting the feed point or bending angle, impedance variation is observed. Impedance shifts symmetrically as the feed point deviates, leading to recommendations for optimal ratios. Model simulations aid in understanding and fine-tuning, crucial for achieving a 50 Ohm match. Practical tuning guidelines ensure efficient antenna performance.

Radio wave propagation describes how radio waves travel from one point to another, classified as ground waves, skywaves, and free space propagation. Ground waves propagate over the earth's surface in low/medium frequencies, bending around obstacles but limited to short ranges. They enable AM/FM broadcasting and military submarine communication.