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Over 1000 _Elecraft_ KX2 owners have benefited from the Kx22 Heatsink, experiencing cooler rig temperatures and higher output powers. PAE manufactures these heatsinks, along with AC power supplies for HF transceivers, remote power relays, and Ethernet relays, with all machined products manufactured in the **USA**. PAE distributes _Fair-Rite_ Mix 31 ferrite snap-it cores and toroid cores, essential for RFI suppression and impedance matching in amateur radio setups. The product line also includes commercial monitoring antennas, UQUI transformers, ULP AC power filters, and 3M conductive adhesive copper tape, catering to various station build-out and maintenance needs. The AM1 Portable Antenna Mount System and its AM1-VA Multi-Angle Adapter offer flexible antenna deployment options. PAE ensures careful packing of fragile ferrite products, with shipping cost adjustments communicated post-order for larger, heavier combinations to guarantee safe delivery.

Constructing an effective antenna support system often involves safely elevating wire antennas into trees or over obstacles. This resource details the build process for the WT8WV "Colossus" air cannon antenna launcher, a pneumatic device designed to project a pilot line over elevated structures. It specifies the use of readily available PVC pipe components and standard hardware, outlining the exact materials required and providing step-by-step assembly instructions for a robust, low-cost solution. The article presents a practical alternative to traditional methods like slingshots, emphasizing the launcher's utility for Field Day operations and general antenna deployment. It includes a comprehensive list of parts, such as 2-inch and 1-inch PVC pipe, various fittings, a sprinkler valve, and a bicycle pump valve, detailing their integration into the final assembly. The total cost for materials is estimated at around $40 per unit, making it an accessible project for many radio amateurs. Crucially, the guide incorporates essential safety precautions for operating a pneumatic launcher, covering aspects like pressure management and projectile selection. It also features multiple photographs illustrating the construction phases and the completed device, offering visual clarity to aid builders in replicating the design.

The article details the design and construction of a four-band Moxon beam by a radio amateur. The beam, mounted atop a rooftop tower, aimed for gain over a dipole on 20 meters, cost under $500, and included additional bands. The design features fiberglass spreaders, four bands (20/15/10/6 meters), and a single feedpoint. The construction involved computer modeling, NEC source code, and specific dimensions. The article outlines the assembly, materials, and tuning process, including in-situ adjustments for optimal performance. Despite initial challenges, the beam improved signal strength and facilitated contacts on multiple bands, marking it as the best HF antenna the author has owned.

The FT-991 is a nice small size and lightweight radio, it is perfect for portable operations. It can be carried along with a laptop computer as hand luggage in airplane. The weak point of this radio, is it does not have a separate RX antenna capability. Therefore i decided to add this feature. On the back side of the radio a BNC connector is added to connect the RX antenna and a switch is fitted to select between RX antenna or main antenna.

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.

Showcasing German engineering, ANjo Antennen develops and manufactures a diverse portfolio of amateur radio and commercial antenna products. Their offerings span a wide frequency range from 1.8 MHz to 3000 MHz, emphasizing electrical and mechanical precision for longevity. The company actively participates in events like FUNK.TAG Kassel, providing opportunities for direct engagement and order pickup. ANjo's product line includes high-performance **Yagi antennas** optimized for Tropo and EME, along with multi-stacked Quad antennas designed for contest operations, featuring wide horizontal and narrow vertical beamwidths. They also produce circularly polarized satellite antennas, some with switchable LHCP/RHCP, leveraging their commercial satellite antenna expertise. Beyond amateur applications, ANjo provides flexible, custom antenna solutions for commercial sectors such as BOS, EMC measurements, and telemetry. Their commitment to quality is evident in the Premium-Line antennas, which utilize **1.4301 (V2A) stainless steel** for mast clamps and connectors, ensuring durability and corrosion resistance. They also offer end-fed HF multiband wire antennas, known for their compact footprint and discreet installation.

This project introduces the Loggi, a hybrid antenna merging the wide frequency coverage of log-periodic dipole arrays (LPDA) with the high gain and front-to-back ratio (F/B) of Yagi antennas. Traditional LPDAs span broad frequencies with moderate gain and low VSWR, while Yagis provide high gain and F/B over narrow bands. By analyzing high-Tau LPDA designs, it was found they could nearly match the gain of VHF/UHF Yagis while maintaining excellent patterns, F/B, and front-to-rear ratios (F/R). Optimizing specific elements for target frequencies (e.g., 144.1 MHz) led to the Loggi, which uniquely features all driven elements without passive directors or reflectors. This design effectively functions as a narrowband optimized LPDA, with front elements acting like Yagi directors and rear elements like Yagi reflectors, thus enhancing gain and directional characteristics while retaining broad frequency versatility.

Cheap and simple fully automatic antenna switching that permit to automatically select the proper antenna based on transceiver status activity.

Learn how to build a compact and efficient HF antenna for ham radio operators with limited space. Follow the author's journey from experimenting with different antennas to creating a magnetic-mounted antenna that covers 7MHz to 30MHz without the need for an ATU. Discover how a portable flagpole can be repurposed for radio communication, allowing you to operate with 100 Watts power output. This project provides a cost-effective solution for hams looking to set up a reliable antenna on their car roof in just 30 seconds.

Andrew Georgakopoulos, SV1DKD, modeled the End-Fed Half Wave (EFHW) antenna using MMANA-GAL software. He evaluated the EFHW-8010-2K from Myantennas.com for field operations, comparing it to random wires, OCFD, and dipole antennas. His results showed similar performance to OCFD, confirming EFHW's practical feeding advantage but with potential high-voltage risks at the feed point

Reception test comparison between IC 756 pro III, IC 7700 and the last jewel by ICOM IC 7851

The PA0FRI Unbalanced/Balanced ATU is a home-built antenna tuner designed to efficiently match a W8JK 2-element beam antenna fed with a 450-ohm twin lead. Based on PA0FRI’s S-Match design, it optimizes energy transfer while maintaining balance, reducing losses, and ensuring proper radiation. The tuner uses a roller inductor, air variable capacitors, and a T200 iron powder coil, allowing fine-tuning across 14-50 MHz. Extensive lab tests confirm minimal attenuation and precise impedance matching, making it a reliable and efficient ATU for balanced antennas.

This is a plan for an optimized element UHF Yagi Antenna for UHF Bands featuring a 9dBd forward gain, a 13 dB front-back ratio, and a bandwith of 10 MHz on the 430-440MHz range.

From March 2 to March 11, 2018, a Norwegian team operated as Z2LA from Zimbabwe, focusing on 160m through 10m bands using SSB and CW modes. The operation, described as "holiday style," aimed to provide contacts for DXers worldwide seeking a rare DXCC entity. Key equipment included a SUNSDR PRO II, an Elecraft KX3, and an Icom 706 MK2G as a spare radio, supported by two Juma 1000 amplifiers for robust signal output across the bands. Antenna systems were tailored for multi-band operation, featuring an Inv L for 160m and 80m, sloping dipoles for 30m/40m, and a _Hexbeam_ from SP7IDX Technology covering 20m to 10m. For improved reception, the team deployed a SAL 30, two reversible BEV antennas from remoteqth.com, and a BOG from K1FZ, enhancing their ability to hear weak signals. QSL information directs operators to Clublog for log search and M0OXO Charles for OQRS, explicitly requesting no bureau cards. The team comprised LA7THA Rune, LA7WCA Arne, and LA9VPA Thor, successfully making numerous contacts and contributing to the DX community's pursuit of _Zimbabwe_ as a DXCC entity.

The Shrunken Quad antenna is a unique design that offers full-sized performance on the 10m and 15m bands while incorporating linear loading via a trap for operation on the 20m band. This design allows for effective communication in the HF spectrum, making it suitable for both casual operators and serious DXers. The quad configuration provides excellent gain and directivity, which is beneficial for contesting and long-distance contacts. Constructing the Shrunken Quad involves careful attention to dimensions and materials to ensure optimal performance. The antenna's compact nature makes it an excellent choice for limited space situations, allowing operators to enjoy the benefits of a quad without the need for extensive real estate. This project is ideal for amateur radio enthusiasts looking to enhance their station's capabilities with a versatile and efficient antenna system.

The PicoFox is a versatile fox transmitter for 2-meter ham radio operators, built around the RP2040 microcontroller. With open-source hardware and software, it can be customized to suit your needs, from APRS to other digital modes. This fully assembled transmitter comes with a rechargeable battery and antenna, ready for use. The design allows for easy addition of features like sensors or interactivity. Modulation is handled in software for smooth FM output, with ample CPU, flash, and GPIO available. Configure your PicoFox by connecting it to a computer via USB and adjusting settings in a text file. Explore the possibilities of this innovative transmitter for your amateur radio projects.

This article explores the marriage of amateur radio and bushcraft, advocating the pleasure of setting up a portable station in nature rather than operating from the confines of a vehicle. The Parks on the Air (POTA) programme is highlighted as a catalyst for outdoor radio activities. The author shares his experiences and techniques, from transporting equipment into the wilderness to setting up shelters and antennas. Knot tying skills and the use of frogs are emphasized for efficiency, and a unique method for launching wire antennas is described. The article emphasizes the synergy between amateur radio and bushcraft skills, enhancing the enjoyment of radio operations in wilderness environments.

This presentation on antennas is a practical guide for amateur radio operators. The key takeaway is that the best antenna for your station depends on your constraints and goals. There is no magic solution and buying a wire antenna is not recommended as it might be expensive and not as effective. The presentation covers different antenna types including dipoles, verticals, Yagis and loop antennas. Important factors to consider when choosing an antenna include SWR, feeder types, and whether you need a balun. The author emphasizes that ATUs don’t improve a poor antenna and advises against obsessing over SWR readings.

This article details the development of an 80-meter antenna within the confines of a restrictive covenant community. Faced with limited space, the author explores various options before implementing a clever hybrid design: a short 30-foot vertical wire running discreetly down the building's exterior combined with a capacitive top hat installed in the attic. Computer modeling confirmed the superiority of capacitive loading over inductive loading, increasing radiation resistance from 6 to 14 ohms. The perimeter wire top hat, naturally supported by the attic structure, resonates effectively at 3.5 MHz. The system is completed with four buried 60-foot radials installed "after dark" to maintain compliance with community restrictions.

A cost-effective alternative to the Optibeam OB10-3W, a high-performance but expensive tri-band Yagi antenna for the 20, 17, and 15-meter bands. The original Optibeam, featuring three full-size elements on each band, delivers strong forward gain and front-to-back ratio but comes with a high price tag. To address this, a custom design was developed, offering similar performance at a fraction of the cost. Using accessible materials and a simple 1:1 current balun, the homemade version proved highly effective, making it a practical solution.

OM0ET manufacture high capacity variable air capacitor and tuning unit designed for Magloop antennas. OM0ET explains features and benefits of this antenna, such as easy assembly, wide frequency range, and improved efficiency. Ideal antenna setup for indoor or outdoor use, offering better QSO performance and radio listening experience. The author, identified as OM0ET, shares insights on the design and functionality of the equipment, making it a valuable antenna for portable operations.

Learn how to construct a balanced Antenna Tuning Unit (ATU) for your ham radio equipment. Follow the instructions provided by Bengt, SM6APQ, to create a variable capacitor insulated from the ground for additional safety. Discover how to set up the ATU for the 20 to 10m band with proper spacing between coils. Use low power when adjusting the ATU for lowest SWR. Avoid using switches and opt for banana plugs for flexible connections. Visit the Creative Science Centre website for more information and resources on ATU construction.

Focusing on the Indian amateur radio community, this resource provides a collection of articles covering news, technical tutorials, and DIY project instructions. It features content on various aspects of ham radio, including club activities, circuit ideas, and general information relevant to operators in India, often referencing local events and regulations. The site serves as a central point for information exchange within the region. The author, VU3HZW, shares insights and practical guidance, drawing from personal experience to present topics such as antenna construction and station setup. The content aims to support both new and experienced hams, with articles detailing specific projects and offering practical advice for improving station performance or engaging in local ham radio activities. For instance, one article might detail a simple _QRP transceiver_ build, while another could discuss optimal antenna placement for **local nets**.

This article is from the book Ham Radio For Dummies and features some tips for portable amateur radio operations, on Field Day or generic outdoor operation, like selecting the proper antenna and portable power.

This article published on QEX details measurements of tree conductivity and permittivity at HF frequencies, addressing a long-debated topic in amateur radio. N6LF conducted experimental impedance measurements on Douglas fir and maple trees using a vector network analyzer with rings of nails inserted into tree trunks. Results showed that tree conductivity increases with frequency while relative permittivity decreases, similar to soil characteristics. Measured conductivity ranged from 0.06 to 0.4 S/m at 10 MHz, aligning with values used in previous research. These findings validate that NEC modeling can reliably estimate trees' substantial impact on HF antenna performance.

A detailed guide presents a simple 2-element quad antenna for 2m, offering ease of construction, portability, and efficient performance across the 144-148 MHz band. The design allows quick disassembly for storage and features adjustable polarization, making it ideal for various applications, including transmitter hunting and SSB operations.

Paul McMahon details the design and construction of a four-element Yagi antenna for the 50-52.5 MHz range, published in Amateur Radio Magazine (Dec 2011). The antenna, featuring a raised driven element and a capacitive/DC connection using copper strips, maintains consistent VSWR and performance despite two years of weather exposure. The design utilizes inexpensive plumbing conduit for the boom and provides detailed construction guidelines, parts lists, and performance analysis through 4NEC2 simulations.

The resource details the construction of a 433 MHz LoRa APRS iGate and a tracker, both built around _TTGO T-Beam v1.1_ microcontroller boards. Each board integrates an OLED screen, WiFi, GPS, and an SMA antenna connector, powered by an 18650 3.7 V lithium-ion battery or microUSB. The iGate operates on 433.775 MHz, with its status verifiable on aprs.fi, demonstrating practical implementation of LoRa-based APRS solutions. The methodology involves programming the modules using Visual Studio Code with the PlatformIO plugin. This process loads the necessary firmware and a JSON configuration file, which includes the operator's callsign and WiFi credentials for the iGate. The guide emphasizes the ease of programming and provides specific steps for configuration. Initial testing of the iGate and tracker, including smart beaconing configuration, is documented. The low power output of approximately 200 mW from the LoRa board's transmitter is noted, with suggestions for range extension through improved antennas or RF amplification. The author, N4MI, plans to deploy a higher-gain 70cm antenna for the iGate.

Demonstrates the construction of an **ATU-100 (N7DDC)** automatic antenna tuner, detailing the assembly process from component arrival to final enclosure. The resource covers winding the tandem match transformer, connecting the OLED display, and integrating optional control buttons. Specific attention is given to modifying the EEPROM settings for **QRP operation**, reducing the minimum tuning power to 1 Watt, and addressing potential RF interference with CPU by adding capacitors to button connections. The build log includes practical tips such as adapting RG58 coaxial cable strands for PCB mounting and utilizing a repurposed Macbook Pro cover for the custom enclosure. The author references external GitHub pages for comprehensive information, R0AEK's resources for additional details, and a video by MW0SAW for EEPROM configuration across different ATU-100 variants. Future plans involve field testing the completed tuner during SOTA or other portable activations.

G6HKS Yagi Kits & Parts provides material kits for building high-performance PowAbeam Antennas, ideal for VHF/UHF enthusiasts interested in DXing. The kits feature advanced Yagi designs, including the unique ParAclip system, ensuring exceptional all-weather stability and minimizing detuning effects. With resources, tips, and support, the site aims to make antenna construction straightforward for amateur radio operators. The focus is on delivering top-tier performance at competitive prices, empowering users to build and enjoy their own high-quality antennas.

This article presents a novel Top Loaded End-Fed Half-Wave (TLEFHW) antenna design for 20-meter ham radio operation. The antenna features a compact 14-foot vertical radiator with a capacitance hat configuration, eliminating the need for radials or ground systems. Using EZNEC modeling and field testing, the design achieves a 1.5:1 SWR across the 20m band with a 4.11 dBi gain. Key features include quick deployment, lightweight construction, and directional radiation pattern with 110-degree beamwidth. The design, while requiring a 45-foot footprint due to the top hat, offers an effective portable solution for amateur radio operators seeking a no-ground, no-tuner 20m antenna option.

Effective suppression of harmonics and parasitic radiation from HF transmitters is crucial, especially with the increasing sensitivity of VHF/UHF radio channels to interference. This project details a hybrid low-pass filter (LPF) designed to operate across the HF bands up to 51 MHz, making it suitable for 6-meter band operations while providing deep VHF/UHF suppression. The design addresses the challenge of modern interference landscapes, where even microvolt-level signals can disrupt wireless sensors and other simple VHF/UHF receivers. The filter utilizes a single elliptic link, combining high cutoff steepness with robust suppression in the hundreds of megahertz range. A key feature is the use of only two standard capacitor values, simplifying construction and component sourcing. The article provides a detailed schematic, performance characteristics, and _RFSim99_ model file, demonstrating a reflection coefficient S11 below 0.017 (VSWR < 1.03) across 1-51 MHz, ensuring minimal degradation to the antenna system. Construction notes include coil winding specifications and capacitor selection guidance, with recommendations for _FR-4_ assembly. Two capacitor sets are presented, with the first variant recommended for its lower RF current demands, keeping currents below 3 A at 1 kW passing power at 51 MHz. Fine-tuning involves adjusting frameless coils, with considerations for capacitor tolerance and high-frequency capacitance measurement accuracy.

Alan (W2AEW) shares his comprehensive portable field radio kit, showcasing various antenna options and accessories for POTA activations. The kit, housed in a repurposed camera bag, features the Elecraft KX2 Shack a Box, AX1 antenna kit, and additional accessories. With thoughtful organization and adaptability, the kit offers flexibility for different deployment scenarios, ensuring efficient operation in diverse field conditions

Elektrodump.nl is an online shop from the Netherlands specializing in amateur radio products. It offers a wide range of categories including antenna masts, antennas, tuners, coax connectors, and cables. The site also features broadcast equipment, electron tubes, semiconductors, and various electronic components like capacitors and resistors. Additionally, it provides measuring equipment, power supplies, and transmitters, catering to both hobbyists and professionals in the field of radio electronics.

Fully functional weathervane conceals an efficient 2- meter base-station antenna. Your Neighbors and HOA won’t know it’s there and they will love the rooster-vane. The Rooster-Tenna is a covert 2-meter ham radio antenna disguised as a functional weathervane, ensuring seamless integration into residential environments. This improved version features a wide-spaced parallel-fed folded dipole in a compact skeleton slot design. Constructed from aluminum tubing and acrylic supports, it offers omnidirectional, vertically polarized performance suitable for repeater and satellite use. Easy to mount and tune, it achieves a low SWR across the 2m band. With 3D-printable parts available, the Rooster-Tenna blends practicality with stealth, making it an ideal solution for HOA-restricted areas

The POCKET TUNER V1.1 is a highly compact HF T-Match antenna tuner designed for QRPp and QRP portable operations. With a credit card-sized form factor, it is tailored for low-power setups, supporting HF bands from 10m to 40m. The tuner features a unique design using rotary switches for precise capacitor adjustments, allowing tuning in small increments. Its inductance selection is optimized for various bands, ensuring efficient performance. Equipped with a resistive tuning indicator, it protects the transmitter by reducing SWR during adjustments. This versatile and portable tuner is ideal for field operations, enabling efficient antenna matching for low-power rigs.

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.

The Acom 1500 HF+6M Linear Amplifier is a high-quality and user-friendly amplifier that provides excellent performance and reliability. G6NHU, who previously owned an Acom 1000, upgraded to the Acom 1500 after nine years and has been using it for about eighteen months. Key features highlighted include the ability to connect three antennas internally, straightforward tuning process, robust construction that can handle high SWR, quiet operation, fast and quiet switching for efficient CW operation, and clean output signal even when driven hard. G6NHU highly recommends the Acom 1500 and states they would not hesitate to purchase another one in the future.

Presents DJ5IL's personal amateur radio station, detailing his journey as a licensed operator since 1973. The resource covers his **shack setup**, including an Elecraft K4D, Icom IC-7610, and various vintage transceivers like the Drake 2-B, along with a SPE Expert 1K-FA amplifier. Antenna systems include a PRO.SIS.TEL RD1524T rotary dipole for 40/20/15/10m at 15m height, an 18m vertical dipole with an SGC SG-230 tuner for 3.5-30 MHz, and an inverted-V dipole for 80m. The site features a **QSL gallery** showcasing his custom card designs and outlines his QSL policy, emphasizing the exchange of unique, personalized cards over generic confirmations. It also includes a detailed operator's biography, tracing his early fascination with radio, obtaining his license at 16, and memorable QSOs, such as a contact with his blood-relative W3NZ. The resource also delves into the historical significance of amateur radio's role in pioneering shortwave communication following the 1912 International Radiotelegraph Convention, which initially relegated amateurs to wavelengths of 200 meters and shorter. DJ5IL's philosophy on "ham spirit" is discussed, stressing the unpolitical nature of amateur radio as a global fraternity.

This article explores the powerful features of AutoEZ as an Excel application working with EZNEC antenna modeling software. The article demonstrates how variables, equations, and formulas enable versatile antenna design and automatic optimization. Through practical examples including dipoles, inverted vees, delta loops, and monopoles, the author shows techniques for achieving resonance, implementing transmission line resonators for broadbanding, and optimizing antennas across frequency ranges. The step-by-step demonstrations cover unit conversion, coordinate calculations, segmentation considerations, and SWR optimization. This practical guide illustrates how AutoEZ extends EZNEC's capabilities, making complex antenna modeling more efficient and accessible.

This article details an Inverted-L antenna design optimized for 160-meter band operation, consisting of a 10m vertical section and a 28m horizontal section supported by Spiderpoles. Despite its relatively low height compared to the wavelength, the antenna has demonstrated impressive DX capabilities, achieving contacts up to 3,453 miles into Asiatic Russia. The system incorporates a Pi-Network ATU at the base for tuning flexibility. While modeling shows a radiation pattern favoring the South, practical operation indicates effective all-round coverage on Top Band.

The Beam project offers various features for controlling antenna rotators, including support for 2 or 4 line LCD displays, software or hardware clocks, open collector drives for azimuth and elevation control, and internal calculations for tracking the sun and moon. It can also track satellites and supports "Flip Mode" for inverted antennas. The 4-line version provides detailed readouts while the 2-line version offers a more compact display. New versions now support PWM and I2C H-bridge modes for adjustable speed control at the end of a move.

This article provides a comprehensive introduction to the decibel (dB), its logarithmic nature, and its applications in power, voltage, and antenna gain calculations. It explains how dB simplifies comparisons in electronics, telecommunications, and audio perception. The author clarifies key mathematical concepts, including power ratios, voltage doubling, and absolute levels like dBm and dBV. The discussion on S-units and antenna system gain is particularly relevant for radio amateurs. Overall, this is an informative and well-structured guide to understanding and applying decibels in technical fields.

Guide to constructing an effective antenna for 50MHz. Inspired by a design from Martin DK7ZB, the article emphasizes the importance of precise measurements and quality materials. With a 2.20m boom and careful assembly, the antenna promises excellent performance, resilience, and cost-effectiveness, making it ideal for six meter band operations.

This paper presents an 80 meter wire 3-element beam antenna in an inverted-V configuration, designed for limited-height towers. Using EZNEC modeling, the antenna features a central parasitic reflector and two switchable driven elements at each end, enabling NE/SW coverage without moving parts or networks. Element lengths are optimized for SSB (3.8 MHz) and CW (3.5 MHz) operation, with a 50 Ω feed and rope-supported boom. The design delivers high gain, effective takeoff angles, and excellent reception, confirmed in real-world DX contest operation. Its simplicity, reliability, and ease of construction make it ideal for operators seeking performance without complex matching systems.

This article describes the design and construction of a 4-meter band vertical sleeved dipole antenna, built to complement a newly acquired Yaesu FTDX10 transceiver. The simple yet effective antenna consists of modified coaxial cable housed in weather-resistant plastic conduit, featuring an integrated 8-turn choke coil. Despite common misidentification as an EFHW antenna, this design is actually a sleeved dipole that provides an excellent 50-ohm match across the band, achieving SWR values between 1:1 and 1.1:1. The project demonstrates an economical approach to entering the relatively quiet 4-meter band.

This comprehensive article dispels common misconceptions about Standing Wave Ratio (SWR) in amateur radio. The author explains that SWR is not an antenna property but a measure of the entire antenna system, representing the mismatch between transmission line and load impedance. Contrary to popular belief, modest SWR values (under 3:1) typically cause minimal power loss in HF applications. The article demonstrates mathematically why obsession with achieving 1:1 SWR is often unnecessary, explains when SWR matters more (QRO, QRP, VHF/UHF), and explores effective matching techniques including proper ATU placement and quarter-wavelength transformers.

DX web cluster that offers features for both registered and unregistered users. Unregistered users can view spots, filter by band and mode, search for callsigns, while registered users get all that plus the ability to submit spots, upload logs, see DXCC country status, antenna pointing info, real-time maps of spots, email alerts for DXCC countries on-air, and more. Basically, register for free to get the full DX cluster experience.

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.

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.