how to build

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40 meters band beverage antenna - The author describes his experience building and using a Beverage antenna for the 40-meter band. Despite encountering some challenges, the antenna offered some improvements in receiving stations compared to a 3-element inverted Vee antenna. The Beverage antenna showed a significant daytime signal-to-noise ratio improvement and received signals better than the Vee antenna. However, the front-to-back ratio was not ideal, and the transmit power seemed to affect the Beverage antenna. Overall, the author concludes that the Beverage antenna might be more suitable for locations with higher noise levels. The total cost of the antenna was around 30 Euros.
[ Hits: 34 | Votes: 0 | Rating: 0 ]

40-80 Coax Trap Dipole - Full article on how to build a home-made wire dipole antenna for 40 and 80 meters band. Article is fully in italian, as it was published on ARI RadioRivista, but is plenty of self explaining pictures that will guide you on homebrewing this trapped dipole antenna for the lower amateur radio bands.
[ Hits: 265 | Votes: 3 | Rating: 9.33 ]

End-Fed Half-Wave Antenna for 20m 40m 80m - How to Design and Build a Field Expedient End-Fed Half-Wave Antenna for 20m, 40m and 80m. This Shorty 80m EFHW comprises a 49:1 autotransformer (to match the very high impedance at the end of a half-wave wire), a half-wavelength wire for 40m (also a quarter-wavelength for 80m), a loading coil and a short tail wire. The coil and the short tail wire (about 6 feet) make up the other quarter wave on 80m.
[ Hits: 141 | Votes: 1 | Rating: 4 ]

High Performance Common-Mode Chokes - This article is an attempt to shed some light on this misunderstood component, covering topics like why you need a common mode coke, what it does, what properties it should have, ho to build one and how to measure its performance.
[ Hits: 131 | Votes: 0 | Rating: 0 ]

Square Halo Antenna for 10 and 20 Meters - How to build a limited space 10 and 20 meter band Square Halo DX antenna. A horizontally polarized antenna for 10 and 20 meter band, which is suitable for a limited space.
[ Hits: 241 | Votes: 1 | Rating: 9 ]

Homebrew an OCF Off-Center Fed Dipole Antenna - This type of antenna is a popular antenna design as the performance is very good across the HF bands and requires little or no tuning. It’s a dipole fed off center with a 4:1 balun at the offset feed point. The antenna shown covers 80, 40, 20 and 10 meters. The formula can also be used to adjust the overall length to cover more or fewer bands and the resulting overall length. 160-10m, 80-10m or 40-10 meters depending on your available space. Other bands will require a tuner.
[ Hits: 198 | Votes: 3 | Rating: 6.67 ]

K4SWL Antenna Plus ^new - This project details building a multi-band antenna for park activations. The author constructs a random wire antenna with a 9:1 UnUn for improved performance. Winding the toroid core proved challenging, but the completed antenna shows promising results in initial tests with an analyzer. Further field testing is planned for a future activation.
[ Hits: 52 | Votes: 0 | Rating: 0 ]

Stacking, Phasing and Matching Yagi Antennas - This is a synopsis of a talk presented to the Sydney VHF DX GROUP by VK2ZAB on how, when and why is convenient to build a Yagi antenna stack.
[ Hits: 240 | Votes: 2 | Rating: 10 ]

Performance of 49:1 Ferrite Core Transformers - There are quite a few recipes for building a suitable transformer for an end fed half wave antenna (EFHW), but I was never sure I really understood the main principles. So, I wound a bunch of transformers, made measurements on them using my NanoVNA, learned how to get what I really wanted out of the VNA measurements, and in the process discovered how to build better transformers and be able to predict what they will do
[ Hits: 151 | Votes: 4 | Rating: 7 ]

DIY Yagi Antenna - This article describes the phases for the construction of a Yagi antenna. The calculations of the parameters are made using 4NEC2 software. This type of antenna is used for transmissions and receptions of electromagnetic waves. The project shown here refers to the frequency of 433.92 MHz.
[ Hits: 108 | Votes: 4 | Rating: 3.5 ]

Creating a Custom IC-705 Paddle Mount - This article describes a DIY paddle mount for the Icom IC-705 radio. Dissatisfied with the high cost of commercial options, the author builds a mount from sheet metal and scrap materials. Construction utilizes hand tools and readily available supplies. The final design offers adjustable paddle placement and tool-free installation/removal. Initial testing shows promise for improved field operation.
[ Hits: 28 | Votes: 0 | Rating: 0 ]

Arduino Morse Code Trainer - How to build a Simplified Arduino CW Trainer, this is a version that does not need a keyboard.
[ Hits: 174 | Votes: 1 | Rating: 9 ]

Morse Code Practice Oscillator - This project builds into a box into which you plug a Morse Code Key. Using the Morse Key creates realistic sounds so you can judge how well you Send. A great tool for beginners to improve Morse sending skills before going on-air
[ Hits: 64 | Votes: 0 | Rating: 0 ]

Building a Raspberry Pi Satellite Tracker Interface - This article provides a step-by-step guide for assembling a Raspberry Pi-based Satellite Tracker Interface, designed to work with Green Heron Engineering's RT-21 controllers and MacDoppler software. The guide covers hardware assembly, SD card image installation, and system configuration for satellite tracking.
[ Hits: 109 | Votes: 2 | Rating: 1 ]