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Illustrates the construction of a compact _Moxon_ beam antenna specifically tailored for the 40-meter band (7 MHz). The resource details a homebrew project by W7XA, emphasizing its design for limited space while maintaining good bandwidth and directivity characteristics. It highlights the practical application of the _Moxon_ rectangle model to achieve performance on a lower HF band. The primary content is a downloadable PDF document titled "40-Meter-Mini-MOXON-Beam-Antenna.pdf," which provides comprehensive illustrations and technical specifications for replicating the antenna. This includes dimensions, materials, and assembly instructions, making it a practical guide for radio amateurs interested in directional antennas for HF. The project demonstrates how a relatively small footprint can yield a directional antenna suitable for DXing or contesting on 40 meters, a band typically requiring much larger arrays for similar gain and front-to-back ratios. The documentation supports hands-on construction.

The Kenwood TH-F6A handheld transceiver can achieve an extended transmit frequency range of 137-174 MHz, 216-235 MHz, and 410-470 MHz by removing a specific diode and chip resistor from the main PCB. This modification also expands the receive range on the A-band to 142-152 MHz, 216-235 MHz, and 420-450 MHz. For the TH-F7E, the transmit range extends to 137-174 MHz and 410-470 MHz, with a corresponding receive range on the A-band. Performing these hardware changes will reset and initialize the radio's memory contents, necessitating prior backup of important channel frequencies. Instructions are provided for constructing a homemade PC programming cable compatible with the Kenwood TH-G71A, TH-F6A, and TH-F7E. The interface utilizes an RS-232-to-logic (0-3.3V) level-shifter and a full-duplex serial connection, adapting the Kenwood PG-4S cable schematic for the TH-G71's 2.5mm and 3.5mm phono plugs. Specific schematic tweaks include changing R1 from 150 ohms to 1K ohm to optimize power from the serial port and adding a 150K ohm resistor between the Radio TXD and ground to manage the 3.3V I/O pin. Detailed plug pinouts for the 2.5mm and 3.5mm connectors are presented, with the interface's TXD connecting to the ring of the 2.5mm plug and RxD to the shield of the 3.5mm plug. Ground connects to the shield of the 2.5mm plug, while the tips of both plugs are no-connects. Debugging procedures cover verifying positive and negative power rails from the serial port, checking component polarities, and testing level-shifting and inversion functions of the interface. Software setup involves enabling "TC ON" (Menu 15 for TH-G71, Menu 9 for TH-F6) and using Kenwood's MCP programming software.

A monoband yagi for 14 MHz a PDF article from 73 amateur radio magazine by AB4GX

Pictures of a 2 meter, 220, 440 copper J-Pole antennas

This project outlines the construction of a 3-element reversible quad antenna specifically designed for the 40-meter band. The materials required include pushup towers, pressure-treated posts, insulated wire, and various electrical components such as relays and a balun. The construction process is straightforward, beginning with the installation of the posts in a straight line, followed by the assembly of the antenna elements and their elevation to the desired height. The antenna's design allows for directional signal reception, making it ideal for operators looking to enhance their communication capabilities on the 40-meter band. The project includes detailed instructions on tuning the antenna for optimal performance, ensuring that operators can achieve the lowest SWR possible. Additionally, the design can be adapted for other bands by extrapolating dimensions, providing versatility for amateur radio enthusiasts. Overall, this reversible quad antenna project is suitable for both beginners and experienced operators, offering a practical solution for improving signal strength and directionality in 40-meter communications.

Band audio equalizer and noise gate compatiable with ICOM, KENWOOD, YAESU and other radios

CyberDX-CW is a software simulation of an amateur radio station monitoring the world. Generates a simulated radio environment, where the operator can tune all of the HF bands and actually hear computer generated station activity

Why 6 meter hams design the best antennas

The MFJ-940 VERSA TUNER II is a useful little antenna tuner for the HF-bands. However it suffers from a minor design error, which can be easily rectified.

10 Band DSP Equalizer for Ham Radio, requires Win 98 or higher, 128 MB, 16 bit sound card.

The Q-signal **QRP** signifies a request to reduce power, and in amateur radio, it defines operating with 5 watts or less for CW and 10 watts or less for SSB. This article addresses common inquiries from new hams regarding the practice, its benefits, and implementation methods. It explains how a 5-watt QRP signal, compared to a 100-watt signal, typically results in only a 13dB drop in signal strength, equating to about two S-units, still providing solid copy under most conditions. Hams choose QRP for various reasons, including seeking a greater challenge in DXing or contesting, reducing band interference, or enabling portable field operations with lightweight, battery-efficient equipment. A modern single-band CW transceiver, key, and antenna can fit into a pocket, offering receiver performance comparable to commercial rigs and extended operation on a small battery. This portability facilitates operations in remote locations where higher-power setups are impractical. Operating QRP can involve simply reducing power on an existing commercial HF rig or building a dedicated QRP transceiver from a kit, such as the **Wilderness Radio SST** with its 2-watt output and 15mA receive current draw. While SSB is viable, CW remains the most popular and efficient mode for QRP due to its superior signal-to-noise ratio. The article lists common QRP calling frequencies across 160m through 10m bands for both CW and SSB, and highlights organizations like QRP ARCI and NorCal that support the QRP community.

A well documented article on a small magnetic loop antenna for the 40 meters band

The K0RWU 75-meter mobile antenna design features a 7.5-foot overall length, incorporating a 2.5-foot loading coil wound with #20 enamel wire on a 1/2-inch fiberglass rod, subsequently covered with 1/2-inch shrink tubing to increase diameter to 3/4 inch. This configuration achieved resonance at 3965 kHz with a 5-foot stainless steel whip. The antenna integrates a matching transformer, identified by larger turns near the PL259 connector, and is constructed using a modified Radio Shack CB antenna base. Construction involves drilling and epoxying a 1/2-inch fiberglass rod into a PL259 connector, feeding #20 enamel wire through the rod, and winding 17 turns of #18 matching coil wire between the PL259 sleeve and the center feed point. The main loading coil fills the 2.5-foot rod section. The design allows the antenna to bend for garage clearance and emphasizes maintaining a 50-ohm feed impedance to prevent vehicle electrical damage. The author also discusses experiences with a Yaesu ATAS-100 motorized antenna and a 10-meter antenna project, noting issues with auto couplers and the ATAS-100's performance on 17 meters. Future modifications considered include adding a small servo for band spreading and increasing the fiberglass rod length for a 3-foot loading coil to improve bandwidth. The antenna's sharp tuning, between 3960 kHz and 3970 kHz, necessitates careful adjustment of coil turns for optimal VSWR.

An home made trapped dipole antenna for 40 and 60 meters band by 2E0HTS

Compiling an extensive collection of technical information, the Repeater Builder's website serves as a critical resource for those involved in amateur and commercial repeater systems. It covers a broad spectrum of topics essential for the design, construction, and ongoing maintenance of these vital communication hubs, drawing from years of practical experience in the field. The site provides detailed insights into various aspects of repeater technology, including specific information on VHF and UHF bands, such as 2-meter systems. Users can find data related to repeater logic, control systems, and interfacing with other radio infrastructure, all presented with a focus on practical application. Authored by Kevin Custer, W3KKC, the content reflects a deep understanding of repeater operations and engineering, offering guidance that extends beyond basic setup to advanced troubleshooting and optimization.

Presents the detailed construction of the _FLA25HV_ antenna, a specialized array optimized for Earth-Moon-Earth (EME) communications on the 2-meter band. This resource provides schematics and practical insights into building a high-gain antenna system capable of reflecting signals off the lunar surface, a challenging but rewarding aspect of amateur radio. It covers the mechanical and electrical considerations essential for achieving the precise pointing and signal strength required for successful moonbounce contacts, often yielding **20 dB** or more gain. Amateur radio operators pursuing EME operations require robust antenna systems and precise tracking capabilities. The FLA25HV design addresses these needs by focusing on element spacing, impedance matching, and structural integrity to withstand environmental factors while maintaining critical alignment for lunar reflections. Such systems are crucial for making contacts over distances exceeding **768,000 km**. This personal page serves as a practical guide for hams interested in constructing their own EME arrays, offering a glimpse into the technical dedication involved in pushing the boundaries of VHF/UHF propagation.

RemAud is a Voice over IP (VoIP) application primarily designed for two-way amateur radio remote control over the Internet. RemAud uses streaming-audio technology in a client-server architecture. It features high radio sound quality, low latency, low bandwidth and very low CPU usage by DF3CB

A project for a multiband HF windom antenna by VE2CV and VE3KLO

FT-1000MP Automatic Band Selection Interface Bob Wolbert, K6XX

Small family run business based at London Heathrow and Poole which covers UK CB radio enthusiast Stock a range of CB radios and CB radio aerials and multiband radios and CB mounts and accessories.

An interesting article on building a 4 elements yagi antenna with gamma match for the 2 meter band. This article include two videos demonstrating assembling procedure by KG0ZZ

CB Radio and 10 through 12 meter band radio dealer. Ranger Communications factory authorized dealer. Service 10 and 12 meter and CB radios.

A new SDR-receiver from the italian SDR developers community. Low-cost, DDS-less Software Defined Radio full coverage receiver for all HF bands, used with powerful software on the PC for multi-mode operation

A small company that specializes in antennas and accessories for radio hobbyists who enjoy DXing the AM broadcast and LW bands

An 87ft inverted L portable antenna working on 80 40 30 20 15 meters band

Terrasat Communications specializes in advanced RF technology for satellite communication, focusing on _Intelligent Block Up Converters_ (IBUCs) and Solid State Power Amplifiers (SSPAs). These products are engineered to enhance satellite link performance, offering features like extended frequency ranges and high power efficiency. The IBUC series, for instance, integrates a BUC with an SSPA, enabling operators to install, configure, and monitor units for both commercial and military satellite applications, ensuring reliable, high-performance connectivity worldwide. The company's offerings support various satellite bands, including C, X, Ku, and Ka, providing solutions for diverse operational requirements. Their technology is designed for robust field performance, with products like the _IBUC2_ and _IBUCG_ models demonstrating the integration of advanced diagnostics and control capabilities, which are crucial for maintaining optimal signal integrity in demanding environments. Terrasat's focus on _SSPA_ technology underscores a commitment to power efficiency and compact design.

Constructing a functional spectrum analyzer for the 0-100 MHz range presents a significant challenge for radio amateurs, often requiring specialized components and careful calibration. This project details a homebrew spectrum analyzer design utilizing common integrated circuits like the _SA605D_ FM receiver IC and _MAR-6_ MMIC amplifiers, aiming for a cost-effective solution. The design incorporates a low-pass filter, RF amplification, a voltage-controlled oscillator (VCO) for downconversion, and multiple IF stages at 150 MHz and 10.7 MHz, with a resolution bandwidth (RBW) of 15 kHz. Critical components such as the _SBL-1_ mixer and varicap diodes are specified, alongside instructions for winding inductors and tuning filters. The analyzer's performance is discussed in terms of input level limitations, specifically the 1dB-compression point and third-order intercept point, to ensure accurate measurements and prevent component damage. The _SA605D_'s logarithmic Received Signal Strength Indicator (RSSI) output serves as the detector, driving the Y-input of an oscilloscope, while a _TL084_ op-amp generates the sweep signal for the X-input. Potential enhancements include adding a step attenuator, improving front-end filtering, and implementing switchable IF filters for variable RBW, allowing for greater versatility in analyzing RF signals.

A 37.6-meter Morgain antenna design provides dual-band operation on 80 and 160 meters without traps. The antenna uses 1.5 mm² stranded copper wire with vinyl insulation, commonly found as domestic electrical wire. Tuning involves adjusting lateral jumper wires for the 80-meter band, with initial positions 30 cm from the arm ends, yielding 3635–3715 kHz resonance with SWR below 1.5:1. For 160 meters, a straight wire length of 18.80 meters per arm is critical, achieving 1840–1850 kHz resonance with SWR below 1.1:1. The Morgain antenna exhibits a 50-ohm feed-point impedance, allowing direct connection of 50-ohm coaxial cable like RG-8X, which handles approximately 500 watts. Spacers and the central plate are constructed from 1 mm thick green fiberglass laminate, with spacers measuring 11 cm and installed every 1.90 meters. The central plate is 11 × 11 cm, designed to secure the coaxial cable mechanically. End supports utilize 3–6 mm thick bakelite terminal spacers, tensioned with nylon ropes.

An homebrew crossed Yagi antenna for two meters band based on DK72B design with pictures, detailed description and tricks by Barry Zarucki M0DGQ

An Active antenna designed for VLF and shortwave radio reception. A small antenna capable of excellent performances on low bands, made on a copper plate and introductio to active antennas.

A simple current balun for the FM broadcast band

The Deutscher Amateur-Radio-Club (DARC) e.V. serves as the largest association for radio amateurs in Germany and Europe, structured into 24 districts and approximately 960 local chapters nationwide. Its core mission involves fostering amateur radio and establishing favorable conditions for the Amateur Radio Service. The DARC actively participates in international affairs as a member of the **International Amateur Radio Union (IARU)**, ensuring German interests are represented on a global scale. Recent activities include the announcement of the FUNK.TAG in Kassel for April 25, 2026, and the HAMCamp at **HAM RADIO** in Friedrichshafen from June 26-28, 2026, offering discounted participation for young operators up to 27 years old. The club also supports special events, such as a short-term award and special callsign DB15ØWG to commemorate the 150th anniversary of the Weimar–Gera railway line, active from April 1 to June 30. Regular updates, like the Deutschland-Rundspruch 11/2026, cover topics from the status of 70 MHz band permissions to satellite deployments like Ten-Koh 2, and contest results such as the WWA YL event. Propagation forecasts, including Kp indices and solar flux values, are provided by Hartmut Büttig, DL1VDL, offering insights into HF conditions and Gray-Line DX opportunities. The DARC also reports on district elections and space-related events like the Bochumer Weltraumtag, highlighting the diverse engagement of its members.

QRZCQ.com provides a centralized online platform for amateur radio operators, integrating a global callsign database with DX Cluster functionality. The service features real-time DX spotting, filtering capabilities for specific bands (e.g., 160m, 80m, 40m, 20m, 15m, 10m), and specialized filters for awards like IOTA, SOTA, WWFF, and QRP activity. It also includes a logbook, QSL manager lookup, contest calendar, and various ham radio articles and news feeds, supporting a wide range of operating activities and information retrieval. The platform aggregates data from multiple sources, offering a dynamic view of on-air activity and callsign information. Users can register for free to access additional services, including a personal logbook, buddy lists, and chat features, fostering community interaction among over 198,600 registered users. The DX Cluster displays recent spots with frequency, DX call, spotter, and remarks, covering bands from VLF to VHF. Beyond DX spotting, the site provides resources such as repeater directories, propagation information, and a swapmeet, making it a multi-faceted tool for both casual browsing and serious DXing or contesting. The service also highlights active users, latest news, articles, and videos, keeping the content fresh and relevant.

Operating Slow Scan Television (SSTV) on Apple macOS systems requires specialized software to encode and decode images for transmission over amateur radio frequencies. MultiScan 3B was an application designed for this purpose, enabling Mac users to engage in SSTV communications. It supported various popular SSTV modes, including Robot Black & Color, Scottie, Martin, PD modes (P3, P5, P7), and AVT, catering to a wide range of operational preferences and compatibility requirements within the SSTV community. The software's capabilities extended to both transmitting and receiving pictures, offering flexibility in how images were processed. Users could select regular, narrow, QRM, and narrow+QRM modes, allowing for adaptation to different band conditions and signal environments. This feature was particularly useful for mitigating interference and optimizing image quality during transmissions on HF bands. MultiScan 3B was built to run on Mac OS X 10.6 and later versions, providing a dedicated solution for Mac users interested in this classic digital mode. Its support for multiple modes and operational settings made it a versatile tool for SSTV enthusiasts.

The NAVTEX system is used for the automatic broadcast of localised Maritime Safety Information (MSI) using Radio Telex (also known as Narrow Band Direct Printing, or NBDP).

A copper pipe Hentenna for 144 MHz. The Hentenna, a compact, high-gain loop antenna developed in Japan in the 1970s, offers approximately 5.1 dBd gain, comparable to a three-element Yagi. Adapted for 2 meters, it is crafted from copper pipe for simplicity, affordability, and broadband performance. Requiring no feed-point tuning, its construction involves soldering standard copper fittings. Installation demands non-conductive materials to minimize signal disruption. Versatile for vertical or horizontal polarization, it is ideal for FM, repeater, SSB, or CW applications. This design emphasizes practicality and performance for amateur radio enthusiasts

A delta loop antenna for 6 meters band with SWR diagram , construction plan and some pictures by IZ8EWD in Italian

Alfa Tango DX is a premier resource for operators on the 11 meters band, providing a searchable database that includes news, cluster information, and discussion boards. This platform serves as a hub for DXers and contesters, offering valuable insights into activations, dx-peditions, contests, and meetings worldwide. The site features a variety of resources, including event calendars, award programs, and tools for logging contacts. Members can access exclusive content and participate in contests like the AT Women's Day Contest and the Eleven World Wide Contest. With a focus on community engagement, Alfa Tango DX fosters connections among operators and promotes the spirit of amateur radio. Whether you are a seasoned DXer or a newcomer to the 11m band, Alfa Tango DX provides essential information and support for enhancing your amateur radio experience. From QSL services to event participation, this resource is designed to meet the needs of all operators interested in the 11 meters band.

Demonstrates practical solutions for reducing **Radio Frequency Interference (RFI)** in amateur radio operating environments, specifically addressing issues with PC monitors, receivers, and transceivers. The resource compiles advice from experienced operators regarding the selection and application of ferrite cores, including split cores and toroidal cores. It details specific material types like **43, 73, 75, and 77 ferrite**, outlining their effective frequency ranges for RFI suppression, such as 43 material for 30-400 MHz and 77 material for 2-30 MHz. The content provides part numbers for various ferrite products from manufacturers like Fair-Rite Products Corp, distributed by Amidon, and discusses their impedance characteristics across different HF bands. It compares the performance of various ferrite materials at frequencies like 4 MHz, noting that 75 material offers 27 ohms, 73 material 17 ohms, and 43 material just under 10 ohms. Additionally, it touches upon the use of bypass capacitors in conjunction with ferrites to create low-pass filters, emphasizing the importance of identifying common-mode versus differential-mode RFI paths for effective mitigation.

You can use almost any Icom handheld to contact your 2720H back in your vehicle for crossband repeating.

The Icom IC-7300 is a popular HF transceiver among amateur radio operators, known for its advanced features and performance. This modification guide focuses on enabling extended transmission capabilities, specifically for MARS and CAP frequencies. The instructions are based on the work of PA2DB and include detailed steps for removing specific diodes to unlock additional frequency ranges. Before proceeding with the modification, users are advised to take necessary precautions, such as ensuring the radio is powered off and using ESD protection. The guide emphasizes the importance of using appropriate soldering techniques and tools to avoid damaging sensitive components. A video demonstration is also provided to assist users visually in performing the mod. While this modification can enhance the functionality of the IC-7300, it is crucial to note that it may void the warranty and should be undertaken at the operator's own risk. The guide serves as a valuable resource for those looking to expand their operating capabilities with this versatile transceiver.

Have you ever wanted to listen in on a serious SO2R DX contest effort? hear what the low bands sound like from New England? enjoy a contest without having access to a radio? This is your chance!

Ari Milano draw and keep updated these pdf files representing the "radioamatori" bandplan, with notes in italian

Spark is a realtime modulator software for Digital Radio Mondiale DRM, DRM+ and analog FM/AM radio standards. The software supports all code rates, bandwidths and robustness modes (A, B, C, D, E) published in the DRM standard as well as all mapping schemes, such as Standard Mapping

The PDF document, titled "J-Poles," presents various J-pole antenna designs covering the 50 MHz to 450 MHz frequency range. It includes construction details for several specific bands, such as a 6-meter J-pole, a 2-meter J-pole, and a 70-centimeter J-pole. The content outlines the fundamental principles of J-pole operation, including the quarter-wave radiator and half-wave matching stub. Each design features specific dimensions for elements like the radiator length, stub length, and spacing, often expressed in inches. The document also discusses feeding arrangements and impedance matching considerations inherent to J-pole antennas. It provides practical guidance for homebrewing these antennas using common materials like copper pipe or wire elements. The resource offers insights into the advantages of J-poles, such as their omnidirectional pattern and ease of construction, making it a practical reference for radio amateurs interested in VHF/UHF antenna projects.

Planning and modelling Delta Loop antennas for all the ham radio HF bands include calculated wire lengths at each mid-band

A simple delta loop antenna antenna for the six metre amateur radio band

For radio amateurs seeking compact and efficient antenna solutions, particularly for restricted spaces or noise reduction, HF loop antennas present a viable option. This resource compiles several articles from the ARRL, detailing the theory, design considerations, and practical construction of various loop configurations. Topics include small transmitting loops, receiving loops, and multi-band designs, often emphasizing their performance characteristics such as directivity, bandwidth, and impedance matching. The collected articles provide insights into the comparative performance of different loop geometries, such as circular versus square loops, and discuss the impact of conductor size and tuning methods on efficiency. Practical applications are explored, including their use in portable operations, stealth installations, and urban environments where noise mitigation is critical. The content often includes construction diagrams, parts lists, and performance data derived from modeling or field tests, enabling hams to replicate or adapt the designs for their specific operating conditions.

Amidon Associates, Inc. provides a comprehensive selection of inductive components, including ferrite toroids like the FT-50-61 and FT-50-43, alongside iron powder toroids such as the T50-2. These cores are frequently employed by radio amateurs for constructing baluns, ununs, and RF chokes, essential for impedance matching and common-mode current suppression in the shack. The company also supplies ferrite beads, split cores, and cable clamp-ons, which are critical for mitigating EMI and RFI in various electronic systems. Beyond core materials, Amidon offers mounts, bobbins, tunable inductors, and specialized wiring components like PTFE tubing, catering to diverse project requirements. They also provide custom winding services, allowing for tailored solutions in both amateur and commercial designs. Top-selling items include the BN-61-202, a common choice for broadband transformers, and the FB-43-801 ferrite bead, often used for decoupling and parasitic suppression in RF circuits. Amidon further expands its inventory by distributing products from other manufacturers, including Gowanda Electronics and Leader Tech, Inc., broadening the range of components available for hams and engineers.

One specific challenge in the KazShack, operating Single Operator Two Radios (SO2R), involved sharing a K9AY receive antenna between two transceivers without direct RF connection or manual feedline swapping. The solution, detailed in this project, adapts the **W3LPL RX bandpass filter** design to split 160m and 80m signals, feeding them to separate radio inputs while maintaining isolation. This approach also addresses the issue of strong broadcast band interference from a nearby 50KW WPTF transmitter on 680kc. The construction utilizes T-50-3 toroids and NP0 ceramic capacitors, built in a "dead bug" style on copper clad board. Each band's filter coils are identical and resonated to the desired frequency using an MFJ-259 antenna analyzer. A single DPDT relay, controlled by a remote toggle switch mounted on an aluminum panel, facilitates quick band switching between radios, simplifying low-band operations. While some signal loss is noted, the expected lower noise levels from the receive antenna are anticipated to compensate, potentially reducing the need for constant volume adjustments during toggling between transmit and receive antennas.