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The M0PLK multiband delta loop antenna project details the construction of a non-resonant, bidirectional antenna designed for 20-10m operation, requiring an external antenna tuner. The design utilizes two 5.65m aluminum tubes arranged at right angles, with 2x 2.80m antenna wires converging into a 2.30m ladder line, feeding a 1:4 balun. The resource provides a comprehensive parts list, including specific dimensions for aluminum tubes (25mm, 20mm, 16mm outer diameter), DX-Wire FS2, and custom 3D-printed components like a middle insulator, tube end caps, and ladder line spacers, with STL files provided. Construction steps cover base plate fabrication from a 300x300x4mm aluminum sheet, balun assembly, tube preparation with slits and threaded holes, and wire attachment with strain relief. Initial VSWR measurements are presented, indicating performance in line with expectations across the target bands. The author reports successful SSB test QSOs to the USA on 10, 12, 15, 17, and 20m immediately after completion. The project highlights the antenna's bidirectional pattern, noting the need for a lightweight, remote-controlled rotator to fully utilize its directional capabilities. Comparisons are drawn to the Cobweb antenna, with the M0PLK design cited for its reduced local QRM pickup. The article references external sources, including M0AWS's detailed report and PC modeling, along with other construction variants and commercial assembly instructions, providing a robust foundation for replication.

The DX FT8 is a compact, multiband tablet transceiver designed for FT8 digital mode enthusiasts. Supporting five or seven HF bands, it integrates an STM32F746-based touchscreen interface for standalone operation, eliminating the need for a PC. The latest firmware (v1.9.2) adds SOTA/POTA calling and free-text messaging. Its efficient power design, unique RF amplifier, and 3D-printed case enhance portability. Open-source firmware and community-driven development make it a versatile choice for portable FT8 operation, ideal for SOTA, POTA, and travel use. DX FT8 TRANSCEIVER PROJECT is a collaboration between Charles(Charley)Hill, W5BAA and Barbaros(Barb)Asuroglu, WB2CBA.

This article shares the author's experience with building antennas. After putting a large magnetic loop project on hold, they decided to try a base-loaded vertical antenna. The author explains how they chose to design a new antenna from scratch, aiming for a frequency of 7 MHz. They describe the calculations needed to find the right coil inductance and how they used 3D-printed parts for the construction. The article wraps up with results from their initial tests, showing good communication on different bands and highlighting the success of their design.

DC plug adaptor using an XT60 connector. 18650 Lithium battery 3 cell carrier, Three band end fed half wave antenna, XT60 chassis mounted flange.

Demonstrates the construction of a portable dual-band Yagi antenna, specifically engineered for _full duplex_ satellite communication on the 2-meter and 70-centimeter amateur bands. The design adapts DK7ZB principles, utilizing tape measure elements for rapid deployment and 3D-printed brackets for structural integrity. It details element spacing, lengths, and the integration of a five-turn choke to mitigate common-mode currents, providing a practical solution for hams seeking a lightweight, self-built satellite antenna. The resource presents the antenna's performance characteristics, including a claimed gain of **4.1 dBd** for 2m and **6.2 dBd** for 70cm, achieved with two elements on 2m and three on 70cm. It contrasts this DIY approach with commercial alternatives, highlighting the cost-effectiveness of repurposing materials. The article includes design measurements and an image of the completed antenna, offering a tangible reference for replication.

A simple 3D Paddel CW Key made of plastic with a standard 3d printer

7MHz to 30MHz operation is achieved with a magnetic-mounted HF antenna designed for car roof deployment, capable of handling 100 Watts without an external antenna tuner. The design incorporates a large base-loading coil with multiple taps, allowing for frequency selection across various HF bands. This coil effectively increases the electrical length of a short telescopic antenna element, compensating for its inherent capacitance. Construction involves 3D-printed components for the coil former and support structures, though conventional building methods using plastic drainpipes are also suggested. The car body serves as the ground plane, with the coil assembly mounted on a 500mm square metal plate secured by super neodymium magnets. Protection under the magnets is advised to prevent vehicle scratches. Detailed instructions cover winding the 30-turn coil with 2.5mm diameter household electrical cable, assembling the 3D-printed parts, and making soldered connections. Taps are staggered every five turns for precise frequency adjustment. Performance examples include a 7913km contact to Japan using a 1.5m element and 100 Watts, demonstrating low-angle radiation and omni-directional pattern with minimal S-point loss compared to a full quarter-wave.

This article presents an RF Choke featuring an 11-bifilar turn winding of #14 house wire on a Fair-rite FT240-31 toroid. The choke is enclosed in a 3D-printed case from Thingiverse, though this may pose thermal concerns at higher power levels. With SWR concerns up to 30MHz, the author plans to employ two series chokes at the rig input for improved performance. This choke offers versatility for portable use, with potential mismatch resolution using an antenna tuner. Further testing is anticipated upon the arrival of new cables.

This blog post documents the author's journey building an APRS micromodem for amateur radio applications. Using an open-source design by LY2EN, the author assembled a cost-effective Terminal Node Controller (TNC) with SMD components, an Arduino Nano, and a JDY-31 Bluetooth module. The construction process included PCB fabrication, careful component soldering, microcontroller programming, and Bluetooth configuration. A custom 3D-printed case protected the completed device. Field testing in Romania showed the device functioned with a Baofeng UV-5R radio, though antenna limitations affected performance. The entire project demonstrates an affordable DIY alternative to commercial APRS trackers.

The QubeDX is a modular CubeSat-style QRP transceiver designed for digital mode operation with remote Wi-Fi control via VNC. This project integrates a QRPLabs QDX 5W transceiver, an ATU-100 antenna tuner, and a Raspberry Pi 5 in a custom 14x14x14cm 3D-printed enclosure inspired by CubeSat design. Prioritizing affordability and functionality, the system operates on a single 13.8V power supply and includes auto-tuning and software like WSJT-X. With a total cost of under €250, it offers a decorative and portable ham radio solution.

This project presents a compact QRP SWR meter featuring a 0.96" OLED display (128x64 pixels) for high-contrast visibility, updated with software fixes for display compatibility, improved low-power performance, and support for ATtiny45/85 microprocessors. A 1.3" OLED version accommodates visibility needs. Designed for HF QRP transmitters (3-15W), it uses a Breune coupler with germanium diodes for accurate SWR measurement. Powered by a AAA battery, the meter offers a standalone solution for impedance matching, with a 3D-printed enclosure enhancing portability.

In this project by building a W2IMU feed horn, the author successfully optimized their 10GHz Small Dish EME project. To position and solder the components together, they used a jig and a conical section made of copper sheet. Stability was ensured by fitting the XLNA to the WG switch. The WG components were shod into a waterproof plastic container, and the feed horn and WG were surrounded by a collar and skirt that were 3D printed. With an average Moon noise of 0.5dB, the Sun and Moon noise readings were better than their previous configuration.

The project details the construction of a GM3OXX OXO transmitter, designed to accommodate **FT-243 crystals** using 3D-printed FX-243 holders from John KC9ON. It presents specific frequency adjustments, noting a 7030 KHz HC-49/s crystal could be tuned from 7029.8 KHz to 7031.7 KHz with an internal 45pF trimmer capacitor. The build incorporates a modified keying circuit to prevent oscillator run-on key-up and includes a TX/RX switch for sidetone via a connected receiver, with the transmitter output routed to a dummy load on receive. Practical construction aspects are thoroughly covered, including the process of cutting a rectangular opening in a diecast enclosure for the FT-243 socket and the selection of a **low-pass filter** (LPF) based on the QRP Labs kit, derived from the W3NQN design. The author achieved approximately 800mW output power from a 14.75V supply, measured with an NM0S QRPoMeter, using a 16.5-ohm emitter resistor in the 2N3866 final stage. The article also touches upon the potential for frequency agility across the 40M band using multiple FX-243 units with various crystals. The narrative includes a brief diversion into Bob W3BBO's recent homebrew projects, such as his Ugly Weekender MK II transceiver, highlighting the enduring appeal of classic QRP designs. The author reflects on the personal satisfaction derived from building RF-generating equipment, irrespective of DX achievements, and shares experiences of making local contacts with the 800mW OXO transmitter on 40 meters.

The Elecraft KX2 and AX1 portable field kit is reviewed for its efficacy in rapid Parks On The Air (POTA) activations, focusing on a specific outing by _K4SWL_. The resource details the setup, including the _Elecraft KX2_ transceiver, _AX1_ antenna with a 3D-printed bipod, _Begali Adventure Dual_ paddles, and various accessories like the Windcamp X2 Side Rails and Tufteln KX2 Protective Cover. It outlines the practical considerations for a quick deployment, such as avoiding tree-thrown lines due to back pain, and emphasizes the minimal setup time required to get on the air. The activation described involved 11 contacts logged on 20 meters within 14 minutes, demonstrating the system's efficiency for "grab-and-go" operations. A QSO map visualizes the contact locations, and an unedited video documents the entire activation process. The review highlights the kit's reliability and compact nature, making it suitable for urban parks or situations where rapid deployment and minimal footprint are essential. The author expresses appreciation for the kit's tidy organization and consistent performance over several years of portable use.