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An homebrew antenna tuner project

The project details a DIY SWR/Wattmeter designed around an _Arduino Uno_ shield, providing capabilities to measure RF power from 2 to **200 watts** and Standing Wave Ratio (SWR) for HF amateur radio bands. This construction features a compact design, integrating the measurement circuitry directly onto a custom PCB that interfaces with the Arduino Uno microcontroller. Key components include a directional coupler for sensing forward and reflected power, precision rectifiers, and analog-to-digital conversion for processing RF signals. The Arduino firmware handles calibration, calculations, and displays the results on an integrated LCD, offering real-time feedback on antenna system performance. The design prioritizes simplicity for homebrewers. Performance specifications indicate accurate readings within the **2-200W** power range, suitable for typical QRP to medium-power HF operations. The project provides schematics and a basic overview of the software logic.

QRP and Homebrew HAM Radio by DL2FI and DL7NIK QRP Made in Germany and more QRP Kits, qrp transceivers, accessories, mini keyers dealer for antennas, atu and more accessories

This homebrewed antenna tuning unit also incorporates a 50-ohm QRP dummy load, power meter (1 or 10 Watts full scale), and SWR meter

K0JD's home construction projects, featuring the R2/T2 modules by KK7B

The EF0604S is a compact 4 elements yagi antenna plan for six meters band featuring 8.77 dBi gain and a front back gain of 17.89 dB. Article includes elements dimensions and spacing, along to pictures of some homebrewed examples.

Traps can be one way round multiband coverage without the need of an atu. Learn how to homebrew your own traps

A remote control box for the SG-237 that allow to turn on and off, check status the SGC tuner remotely by AA5TB

ST2NH blog - first ham blog from africa fatures QRP,Homebrew,news,links

Examining the _Angle of Radiation_ and its impact on amateur radio operations, the resource provides insights into optimizing antenna performance for DX and local contacts. It features a design for SPOTTO, a direct conversion high-performance universal DSB transceiver, detailing its construction and operational characteristics for homebrew enthusiasts. Additionally, the site presents a 7-element VHF high-gain antenna design, offering practical schematics and expected performance metrics for those seeking enhanced gain on VHF bands. The resource also covers the development and popularity of the _FT8_ digital mode, highlighting its effectiveness in weak-signal conditions and its role in special event operations like the FT8DMC anniversary. It includes information on Hamfest India 2023 and the Lamakaan Amateur Radio Convention, providing dates and organizational details for significant Indian amateur radio gatherings. Technical articles on Direct Digital Synthesizers (DDS) VFOs and low-cost multifunctional frequency counters offer practical project ideas for radio amateurs.

A system designed to automatically tune small transmitting magnetic loop antennas, particularly beneficial for **contest operations** where rapid frequency changes are common. The core of the system involves a PC-based control application, AutoCap, written in C#, which monitors antenna SWR via an external meter and commands a motor interface to adjust the loop's variable capacitor. The software is compatible with Windows and Linux via the Mono framework, offering a graphical user interface for monitoring system status, SWR, power, and motor commands. Key components include one or more magnetic loop antennas equipped with DC or stepper motors for capacitor adjustment, an SWR meter with data output (such as the Telepost LP-100A or a homebrew serial/USB SWR meter), the AutoCap PC software, and a motor interface. The most effective motor interface utilizes an **Arduino-based controller** with custom firmware, providing precise control over both simple DC motors and stepper motors, and supporting features like motor braking for finer adjustments. The system allows for configurable SWR thresholds, pulse widths, and motor effort settings to optimize tuning speed and resolution. Optional radio integration provides frequency hints, enabling the algorithm to learn the relationship between motor actions and resonant frequency, thereby speeding up initial tuning responses. The software also supports antenna profiles, allowing operators to save and recall specific configurations for different loops, including accumulated frequency hint data.

Accurate frequency measurement is crucial for amateur radio operators, particularly when building or troubleshooting transceivers and test equipment. This resource details the construction of a _PIC microcontroller_-based frequency counter, providing a practical solution for precise frequency display. The design incorporates an LCD readout, offering clear visual feedback of measured frequencies. The counter can operate as a standalone unit, useful for general bench testing, or be integrated directly into a receiver. Its built-in offset functionality allows for seamless integration, enabling the display of the received signal frequency rather than the intermediate frequency. The project focuses on accessible components and construction techniques, making it suitable for homebrew enthusiasts. Key features include a measurement range up to **50 MHz** and a compact form factor.

A magnetic loop antenna for the VHF band, featuring a high gain that can be compared to a quarter wave vertical antenna

Documents the operational experiences and technical insights of amateur radio station VA3STL, offering a firsthand account of various on-air activities and equipment. The blog features a detailed narrative of a **QRP transatlantic QSO** on 12m SSB, achieving a 55 report with 10W to a mobile station in Italy using a homebrew 90ft doublet antenna. It also introduces the _Ten-Tec 539_ QRP HF transceiver, a 10W output rig covering 80m through 10m, designed for portable operations and featuring DSP and dual VFOs. The resource also delves into historical radio technology, specifically the "Gibson Girl" survival radio, an emergency transmitter operating on 500kHz (and later 8280/8364 kHz) with a hand-cranked generator and kite-deployed antenna. This section explores its origins from German designs and its use during World War II, including its distinctive curved shape for ergonomic hand-cranking. Further historical content includes a visit to Signal Hill in St. John's, Newfoundland, commemorating Marconi's reception of the first transatlantic radio signal in 1901. The post describes the Cabot Tower exhibit and the VO1AA station, highlighting the site's significance despite the thick fog during the visit. It also showcases a homebrewed _Marconi-style straight key_ by WB9LPU, crafted to celebrate the centenary of Marconi's achievement.

This article presents an innovative homebrew antenna design utilizing surplus ladder line as a receiving antenna for HF and MF bands. The Ladder Line Antenna (LLA) transforms standard 450-ohm ladder line into a directional, bidirectional, or omnidirectional antenna system through different termination methods. The design, which requires minimal space and height, achieves 6-10dB front-to-back ratio on 40-160m bands using a 33-foot length. This DIY wire antenna project offers an efficient, low-profile solution for amateur radio operators, featuring broadband operation without ground radials and easy installation below fence height.

There are quite a few variants of the design accompanied with many opinions on the effectiveness of the antenna. This page features links to some similar projects and a homebrewed personalized version of this portable antenna tuner

This page, authored by VU2ESE, delves into the sBitx, a Software-Defined Radio (SDR) designed for homebrewers. The content covers the hybrid SDR circuit, software, user interface, hacking/modifying the sBitx, performance, and more. It explores the various components of the sBitx, including the exciter, filters, amplifiers, digital circuit, and modems. The page aims to provide information and guidance for hams interested in building their own SDR. Readers will learn about the capabilities, features, and adaptability of the sBitx, making it a valuable resource for DIY radio enthusiasts.

The Homebrew uSDX SDR TRX is an experimental transceiver primarily designed for CW and Digital modes due to limitations in meeting FCC requirements for SSB. Developed from the QRP Labs QCX, it incorporates advanced SDR features while utilizing an 8-bit ATMEGA328P. The µSDX community fosters open-source development with various design streams and versions, encouraging collaboration and sharing among enthusiasts.

This article details the design and construction of a compact 20-meter QRP SSB transceiver by Pete Juliano, N6QW, measuring just 2 x 4 x 2 inches—small enough for a shirt pocket. Inspired by a 1963 QST design and refined from a prior version, it employs bilateral circuits, a 4.9152 MHz homebrew crystal filter, switched-crystal VXO for 60 kHz coverage (14.160-14.220 MHz), and standard components like ADE-1L mixers and IRF510 PA for 1W output. Key innovations include a double-sided PCB skeletal frame for shielding and isolation, Vectorboard sub-assemblies, and ultra-miniature relays. The bilateral receiver/transmitter shares stages, omitting AGC for simplicity, while a W3NQN LPF and optional 10W external amp enable DX contacts. Tune-up focuses on crystal matching and bias for linearity. Videos on YouTube demonstrate performance, confirming excellent stability and audio. Total cost nears $100, prioritizing portability over features like CW.

The _DX EXPLORER_ blog serves as a personal chronicle of amateur radio experiences, particularly emphasizing homebrew projects and DIY radio equipment. It provides insights into constructing various transceivers and receivers, such as the Minimalist CW Transmitter and the Sputnik Regenerative Receiver, offering practical guidance for those new to the hobby. The content often details the assembly and operation of low-cost kits like the $3 Pixie Transceiver, demonstrating accessible entry points into radio construction. Beyond building, the site also features reviews of commercial gear, including the Tidradio TD-H8 Radio, providing an operator's perspective on performance and utility. The author, YO6DXE, shares a learning journey, aiming to inspire fellow enthusiasts to engage with the technical aspects of amateur radio. This resource covers a range of topics from basic circuit explanations to practical operating tips, fostering a deeper understanding of radio principles. The blog's focus on personal experimentation and project documentation makes it a relevant resource for hams interested in hands-on learning.

A podcast dedicated to the technical aspects of amateur radio, featuring in-depth discussions on homebrewing, test equipment, and project building.

Demonstrates the construction of 'The Virgin', a **direct-conversion receiver** specifically designed for the 40m amateur radio band. This project, completed in February 2016, features a fixed operating frequency determined by a crystal oscillator, requiring a physical crystal change to alter the reception frequency. The design incorporates two integrated circuits and a power regulator, emphasizing simplicity with a single control knob. The author details the initial design, subsequent modifications to the front end, and troubleshooting steps addressing common issues like audio motorboating and power supply instability. The resource presents the final design of the receiver, reflecting the author's first experience building such a unit between December 2015 and February 2016. It offers practical insights into basic circuit construction and the iterative process of refining a homebrew radio project. The content is particularly relevant for those interested in fundamental receiver principles and hands-on **QRP** transceiver building.