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VE1ZAC's analysis details the performance of **MFJ927** and **SGC239** autotuners with portable HF vertical antennas, specifically comparing 31 ft and 43 ft configurations. The resource originated from challenges encountered during a Maritime QSO Party roving operation, necessitating a lightweight and easily deployable antenna system. Target bands for the contest included 80, 40, 20, 15, and 10 meters, with a maximum power handling of 100 W CW. The author utilized a 30-foot carbon fiber push-up pole to support a vertical wire element, noting its 2 lb weight and reliability. EZNEC modeling was employed to predict performance, showing favorable results for a 30-foot vertical with elevated radials, particularly on 40 and 20 meters. Feedpoint impedance measurements, taken with an AIM4170C, are presented for various HF bands, both with and without a 41-foot RG6 stub designed to reduce reactance on 80 and 20 meters. The stub significantly improved matching on these bands, easing the tuner's workload. Operational tests revealed issues with the MFJ927's reliability during contest setup, leading to reliance on the K3's internal tuner. The SGC239, tested post-contest, performed flawlessly. A detailed side-by-side comparison covers mechanical aspects, connection options, power bias, impedance range, board quality, and documentation. Modifications to the MFJ927, including a new aluminum case, white paint for heat reduction, and upgraded impedance-measuring resistors, are also described.

This blog chronicles over a decade of portable HF contesting from rural Ireland (2008–2019) by Olivier, operating under callsigns EI/ON4EI, EI8GQB, EI1A, and EI7T. Using only green energy from a caravan, he achieved top-tier results in major international contests—including 1st World in the 2018 IARU HF Championship (SSB LP) and multiple 1st-place finishes in CQ WW and CQ WPX SSB Europe. Operating in the demanding Single Operator All Band Low Power and SO2R categories, he deployed up to five antennas across five bands, often in remote or emergency-style conditions. The narrative blends technical detail, fieldcraft, and personal reflection, documenting triumphs, setbacks (including carbon monoxide poisoning), and the logistical challenges of sustainable portable operation—culminating in his decision to transition to team-based contesting and future DXpeditions.

Twenty 1-watt carbon film resistors are configured in parallel to construct a 50-ohm **dummy load** for amateur radio applications. The design incorporates a heatsink for thermal dissipation and an **SO-239 connector** for RF input, making it suitable for QRP operations. This budget-friendly project details component selection, soldering techniques, and mounting procedures, achieving a continuous power rating of 10 watts and intermittent handling of up to 100 watts across HF and VHF frequency ranges. The resource provides a step-by-step guide for assembly. This construction offers an economical solution for essential shack tasks such as antenna tuning, transmitter testing, and SWR meter calibration without radiating an RF signal. The utilization of readily available components significantly reduces the overall build cost compared to commercial alternatives, providing radio amateurs with a functional and reliable test accessory. While specific VSWR measurements are not provided, the design prioritizes practical utility for low-power transceiver diagnostics and general RF experimentation.

Learn about the HAMTV Digital Amateur Television (DATV) transmitter on the International Space Station (ISS), transmitting video and audio in MPEG-2 format using the DVB-S protocol. Discover its history, installations, failures, and repairs, as well as the current status and live video feed. Explore the technical details and challenges of the HAMTV transmitter, including power output, polarization, and antenna location. Find recordings of previous transmissions and understand the potential signal reflections caused by various ISS components. Stay updated on the latest developments and activities related to HAMTV from the ISS.

Python NEC2++ Module wraps the C++ API for antenna simulation of nec2++. It is easier to work with, and more powerful than the C-style API wrapper. Works with Python 2.7 and 3+.

The Gemini Amplifier Remote Control software operates on Windows 7 and above, facilitating remote management of the Gemini HF-1K and DX-1200 amplifiers. Users connect via Ethernet, configuring the amplifier's IP address through the front panel. The software allows seamless band and antenna selection, saving settings for each band without requiring transmission. Integration with _OmniRig_ from Afreet Software, Inc. enables automatic band adjustments based on the radio's frequency changes. Users can configure serial or virtual serial connections, with tracking options accessible through the ribbon bar. The software supports speech functionality, enhancing accessibility for operators. Firmware updates, such as version 2.5Ee, introduce features like background datalogging and power output control, uploaded via FTP. Version 1.2.0 allows users to offload internal parameter data for support purposes. The firmware upload process requires the amplifier's IP address and port 21, taking approximately 90 seconds. Users are encouraged to upgrade to the latest firmware for improved performance and remote diagnostics.

Details the construction and performance of a phase-controlled receiving array, specifically a **MicroSWA** variant, optimized for QRP low band fox hunting on 40M and 80M. The resource documents the author's iterative design process, addressing significant regional noise challenges encountered during 0100-0230 UTC fox hunt periods. Initial experiments involved a director wire on a 40M vertical, yielding limited improvement, prompting a shift towards advanced null-steering techniques. The project leverages concepts from Victor Misek’s "The Beverage Antenna Handbook" and Dallas Lankford’s extensive work on phased receiving antennas for urban lots. A key modification involved integrating a new passive phase control box and a push-pull **Norton common base preamp** using 2N5109 transistors, designed for high third-order intercept performance to maintain weak signal integrity amidst strong adjacent signals. The system incorporates Faraday-shielded transformers with RG174 primaries on -75 ferrite cores, housed in ABS plastic pipe. Performance tests confirmed the MicroSWA's ability to produce deep, steerable nulls, achieving approximately 30 dB noise reduction on 160M, 80M, and 40M. This enabled detection of QRP signals undetectable on conventional transmit antennas. The final unit includes front panel controls, a 10-11 dB preamp, and a robust power conditioner, demonstrating effective noise mitigation for challenging low band QRP operations.

This presentation explores the practice of QRP (low-power) amateur radio operation in outdoor settings. It guides operators to identify their specific objectives for portable operations, which inform equipment and antenna choices. The discussion covers considerations including portability, operating modes, power requirements, and weather resistance. Various antenna designs are examined, from vertical configurations to dipoles and end-fed options, with emphasis on deployment practicality in public spaces. The presentation concludes with practical advice on selecting operating locations, RF safety, and resources for equipment and community support for QRP enthusiasts.

The W6PQL 23cm Beacon Project describes a **1296 MHz** beacon designed for microwave propagation studies and equipment testing, capable of 30 watts output. It utilizes a PIC 16F628A microcontroller to generate CW and FSK keying for a crystal oscillator, followed by a series of frequency doublers and triplers to reach the target frequency. The final power amplification stage employs a Mitsubishi M57762 module, providing a robust 10-watt RF output. The design emphasizes stability and reliability for continuous operation, with the microcontroller code, written in assembly, provided for customization of the beacon's callsign and message. Originally located in CM97am and aimed at 140 true, the beacon used four 4-foot Yagis stacked vertically for a total ERP of 3kW. The article includes schematics, parts lists, and construction notes to guide builders, along with antenna pattern measurements. Although the beacon itself is no longer in service as of August 2010, the detailed documentation remains a valuable reference for amateur radio operators interested in building similar **microwave** projects or understanding beacon operation.

Demonstrates the construction of a portable 2-meter repeater system utilizing a **Yaesu DR-1X** transceiver, configured for both analog FM and C4FM digital voice operation. The design emphasizes portability, robustness, and effective thermal management, incorporating a "wind tunnel" airflow system with a fan to maintain transmit module temperatures at 38 degrees Celsius during continuous operation. The system integrates a diplexer, control head, and is housed in a compact, lightweight case weighing under 8kg, designed for single-person deployment. Covers practical considerations for field deployment, including power sources, antenna types, and the overall system architecture for public service events and emergency preparedness. The resource details the modular "wrap around" construction, showing how components like thermal switches for fan control and Anderson Powerpole connectors are integrated. It highlights the system's ability to provide reliable communications support for club activities and emergency communications.

Presents an online retail platform for amateur radio operators, showcasing a diverse inventory of equipment and accessories. The site lists popular transceivers such as the _Icom IC-7300_ and _Icom IC-7610_, alongside various antenna solutions including base, HT, mobile, and end-fed designs. Operators can find coaxial cable, including bulk options and products from "The Wire Man," essential for shack setup. The platform also stocks crimping and stripping tools, adapters, and power supplies, crucial for station maintenance and construction. Test equipment like _RigExpert Analyzers_ and accessories such as Daiwa meters and _West Mountain Radio_ Power Poles are available. Additionally, the site offers software from _Ham Radio Deluxe_ and _RT Systems_, catering to logging and radio programming needs. Shipping policies include free shipping on C.Crane Radios and most orders over $100.00 within the lower 48 states, providing clear purchasing incentives.

The Anytone AT-D878UVII Plus, a dual-band transceiver, supports both Analog and DMR modes, providing versatile communication options for amateur radio operators. This model is complemented by the Anytone AT-6666 Pro, which delivers a substantial 80W output, catering to users requiring higher power for their radio operations. For mobile and off-road applications, RadioSmart Solutions features a 4x4 Mobile Radio Package Deal, which includes the RTS DV-2135s Mobile Two-Way Radio. This package is specifically designed for reliable communication in challenging environments, often encountered during off-road adventures. An _RSS Rugged Off-Road Antenna_ is also available, engineered to withstand harsh conditions and ensure robust performance. The product range addresses the needs of individuals seeking durable and functional communication solutions for both general amateur radio use and specialized mobile deployments.

TX5EU 2026 DXpedition to Raivavae Island, **OC-114**, within the Austral Islands, providing a detailed account of the German/Dutch team's operations. The resource outlines the participation of operators such as DL2AWG Guenter, PA2KW Evert, and DK2AMM Ernoe, who engaged in CW, SSB, RTTY, and various digital modes. It documents the real-world challenges encountered, including significant equipment failures and antenna damage to 80/60m, 30m, and 10m verticals due to adverse storm conditions. The page offers timely news updates on the expedition's progress, noting repairs to a power amplifier's 10/12m bandpass filter, which enabled three stations to utilize amplification. Earlier reports highlighted power failures and the loss of multiple power amplifiers, necessitating one station to operate barefoot FT-8 with 100W. The team's persistent efforts to repair antennas as weather permits are also detailed, reflecting the dynamic nature of remote island operations.

Operating an **Echolink** gateway on the 4-meter band presents unique opportunities for extending VHF communications, as demonstrated by the EI4FMG node. Situated at Fieldstown, Monasterboice, this gateway provides coverage across a significant portion of Ireland's east coast, leveraging a Tait TM8100 radio and an EI4JR Echolink interface logic. My own experience with similar setups confirms the importance of strategic site selection for maximizing reach, particularly with a 122-meter elevation above sea level. Access to the EI4FMG gateway, identified by node 57006, requires a **CTCSS** tone of 88.5 Hz, a standard practice for managing access and minimizing interference on shared frequencies. The system transmits with 15 watts of power and utilizes a Sigma CAT70 @5MAGL antenna, a configuration well-suited for regional VHF coverage. The gateway also features an auto-ID every 8 minutes, ensuring compliance and clear station identification. Users can interact with the gateway using various DTMF commands, allowing for connections to specific nodes, random repeater/link or conference nodes, and managing disconnections. These functionalities streamline the process of linking into the broader Echolink network, enabling local VHF operators to communicate globally through the internet backbone.