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Constructing a 4:1 Guanella current balun involves cross-connecting two 1:1 current baluns. At the low-impedance end, transmission lines from each balun are connected in parallel, while at the high-impedance end, they are connected in series. This configuration allows the device to achieve a 1:4 impedance ratio, effectively transforming a 200-ohm load to 50 ohms. The balun described utilizes **FT240-43 toroids** wound with 2.5mm2 twisted pair cable for 8 turns, intended for use with a 20m **Deltaloop antenna**. Measurements performed with a 200-ohm resistor demonstrate satisfactory VSWR and impedance characteristics across the HF bands. The article compares the performance of 2.5mm2 cable versus 1mm enameled wire, recommending the former for superior efficiency. Emphasis is placed on maintaining short core-terminal connections to optimize performance. Additional considerations include the option of integrating a separate Common Mode Choke (CMC) for enhanced common mode current suppression, especially if the balun's inherent suppression is not prioritized.

SDR Television v1.0 operates as a DVB-S2 / AAC / H264 / H265 program, specifically engineered for QO-100 satellite Digital Amateur Television (DATV) operations. It provides a full-duplex solution on modern x86 computers running Windows 10 or 11 (64-bit, 8+ cores, AVX2 support recommended), leveraging DLLs from _SDR Console_ for control of devices like _Pluto_ and _LibreSDR.TV_. The software requires installation of the SDR Radio kit for wideband mode support. Initial development focused on a proof-of-concept for QO-100, with future enhancements planned to include H266 / AV1 / Opus codecs and an improved cross-band user interface. The current stable release functions reliably for QO-100 DATV. Users must install the SDR Radio kit, followed by the SDR Television kit, into the same directory. Support inquiries are handled via the SDR-Radio.com mailing list, ensuring direct assistance for operational questions.

Early 20th-century transatlantic wireless communication efforts involved distinct technical approaches by Reginald Fessenden and Guglielmo Marconi. Marconi's systems, operational until approximately 1912, primarily utilized _spark technology_ for wireless telegraphy, facilitating Morse code communication between ships and across oceans. His Poldhu station in December 1901 radiated signals in the MF band around 850 kHz, later evolving to 272 kHz in October 1902, and eventually 45 kHz by late 1907 with increasingly larger antenna structures like the pyramidal monopole and capacitive top-loaded arrays. Fessenden, conversely, focused on _continuous wave transmission_ for wireless telephony, recognizing its necessity for speech. His transatlantic experiments in 1906 employed synchronous rotary-spark-gap transmitters and 420-foot umbrella top-loaded antennas at Brant Rock, MA, and Machrihanish, Scotland, tuned to approximately 80 kHz. Fessenden later utilized the _Alexanderson HF alternator_ at 75 kHz by late 1906 for pure CW transmission, integrating a carbon microphone for amplitude modulation. Receiver technology also differed, with Marconi initially relying on untuned coherer-type detectors, later developing the magnetic detector in 1902, while Fessenden's CW approach necessitated more advanced detection methods.

Presents detailed expedition charts and statistics for the **XX9W** DXpedition, covering operating time, total QSOs, unique calls, and duplicate QSOs. The resource provides comprehensive band and mode breakdowns, including FT8, SSB, CW, and FM, across 80m, 40m, 30m, 20m, 17m, 15m, 12m, 10m, 6m, 2m, and 70cm. Users can access DXCC statistics by band and mode, daily QSO totals, and multiband QSO statistics. Continent-by-mode and continent-by-band breakdowns are also available, detailing activity from Africa, Asia, Europe, North America, Oceania, and South America. The platform also tracks the expedition's impact on user totals, showing new band, new mode, new band + new mode, new slot, and new DXCC contacts.

Presents the S21WD DXpedition to Bangladesh (IOTA **AS-140**) scheduled for 2026, organized by the Next Generation DX Club e.V. It outlines the project's progress, including final hardware and systems testing, and the team's successful arrival and activation from the target location. The resource provides a concise summary of Bangladesh, covering its geography, cultural aspects, and economic landscape. The page includes the Clublog Most Wanted ranking for Bangladesh, categorized by continent and mode, as of January 2026. The DXpedition aims to achieve over 70,000 QSOs across CW, SSB, RTTY, and FT8 modes, with a specific focus on RTTY (targeting over 2,000 QSOs) and **lowband** operations. The team plans a Multi-Single entry in the ARRL CW 2026 contest. QSO data will be uploaded to Clublog and LoTW, with Clublog livestream and daily free LoTW uploads anticipated, contingent on stable internet connectivity. The S21WD callsign corresponds to CQ Zone 22 and ITU Zone 41. Further details include a preliminary bandplan, FT8 operating guidelines using MSHV software, a VOACAP DX Prediction link, and an azimuthal map centered on Bangladesh. QSL services are managed by DJ4MX via Clublog OQRS, offering direct, bureau, and LoTW options, with daily LoTW uploads expected.

The 4m Slim Jim antenna project provides a construction guide for a low-cost, high-performance aerial designed specifically for the 70 MHz FM band. This design achieves a 1:1 SWR across the 4m FM band with straightforward adjustment of the feed point, utilizing RG-58 coax. Its low angle of radiation contributes to effective signal propagation. Construction involves using plastic knitting needles as spreaders and a telescopic fishing pole for support, with components secured using two-part epoxy. Annealed bare single-core copper wire forms the radiating element. The setup process includes raising the antenna at least 3 meters above ground for tuning, adjusting the RG-58 feed point for optimal SWR, and then soldering connections. Waterproofing is achieved with yacht varnish. The design emphasizes low wind resistance for durability, making it suitable for exposed outdoor installations. A PDF construction diagram is available to supplement the written instructions.

Open Signal, a software application for Windows 10/11 and 64-bit Linux, facilitates the transmission of color pictures, photo files, and text over HF and VHF amateur radio bands. It integrates its own error-corrected OFDM digital picture mode, delivering pixel-exact images in under a minute, with classic analog SSTV across six families: Martin, Scottie, Robot, Wraase, PD, and MMSSTV's MP/MR, featuring automatic VIS mode detection on receive. The application offers four distinct sending methods, including byte-exact JPEG transfer, a hybrid mode utilizing internet for full quality with a short RF link, and its proprietary digital waveform. This self-contained executable eliminates the need for external software like FLDIGI, Hamlib, or virtual audio cables, simplifying setup. It includes a self-filling logbook that integrates with Wavelog/Cloudlog, eQSL, and provides UDP ADIF broadcast. Built-in spotting features include PSK Reporter, DX cluster announcements, and APRS-IS position beacons. The receive-only version is permanently free, while a full license, enabling transmit capabilities and access to the live network, is available for an annual or lifetime fee. The software is actively maintained, unlike EasyPal, which has not seen updates since 2014.

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.

Presents the 4th edition of the IARU Region 1 Ethics and Operating Procedures for the Radio Amateur, a fully rewritten guide published in July 2026. It establishes a shared basis for respectful and effective communication within the amateur radio community, building upon over fifteen years of prior work. The document details the purposes of amateur radio, principles of non-interference, electromagnetic compatibility, and station safety. It specifies operating procedures, including listening practices, adherence to IARU and national band plans, appropriate transmission content, use of Q-codes, and the phonetic alphabet. The guide provides instructions for conducting QSOs across phone, CW, and various digital modes. Specific sections address managing pileups, participating in contesting, engaging in DX and DXpedition operations, operating portable or mobile, and conducting station testing. Further sections cover VHF and UHF operating considerations, ensuring a comprehensive resource for both experienced operators and those new to the hobby.

Manages log consistency across multiple digital mode applications, specifically addressing the common issue of log divergence between _MSHV_ and _WSJT-X_ for FT8, FT4, and other weak-signal modes. This prevents duplicate contacts and ensures accurate DX tracking when using both programs. The utility computes a deduplicated union of entries from both `_mshvlog.edim` and `_wsjtx.log` files, then updates each log with missing QSOs. It supports a deduplication key based on callsign, date, time (to the minute), band (derived from frequency), and mode. The tool is available as a standalone Windows executable or a Python version requiring Python 3 with _Tkinter_. Users select log folders, close both applications, and initiate the 'Merge' function. The process includes automatic timestamped backups of log files before any modifications, safeguarding QSO data.

The H49A DXpedition to the Solomon Islands (OC-047, IOTA OC-047) is scheduled for a 13-day operational period, commencing on October 9th and concluding on October 21st, 2026. This **DXpedition** will feature a six-member team, including Rolando (9A3MR) as Team Leader, Zrinko (DK8ZZ/YT3ZZ), Mladen (9A2NA), Frane (9A3CJY), Kristijan (9A4WY), and Livio (9A7Y). Operations are planned across all **HF bands** and 6 meters, utilizing CW, SSB, and FT8 modes. This activity provides a significant opportunity for radio amateurs worldwide to log the Solomon Islands, a sought-after DXCC entity. The team aims to maximize contacts across various bands and modes, contributing to global DXCC and IOTA awards. Specific QSL routes and logistical details are anticipated to be published closer to the operational dates.