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Optimizing the cable connections for cat control and audio input output by implementing the digirig mobile. A small audio and rig control interface, with a single USB cable supports most QRP radios requiring external audio and CAT control facilities

Learn about the LinHT handheld SDR radio, an open-source, Linux-based project that is shaking up the ham radio and SDR communities. This guide is perfect for hams new to digital voice and interested in exploring experimental radio platforms. Discover what sets LinHT apart from traditional handheld radios, how it leverages SDR technology and Linux operating system, and why it's generating buzz in the ham radio landscape. Dive into the world of software-defined handheld radios with this beginner-friendly overview.

The document details the construction and performance of a rotatable flag antenna designed for a small lot. The 7x14 feet flag, built with fiberglass poles and an aluminum hub, shows improved reception compared to the author's previous transmit antenna. Key components include a conventional transformer for impedance matching and a variable resistance termination system to optimize performance. Despite challenges like nearby objects affecting signal patterns, the antenna consistently provides better signal-to-noise ratios, making it a valuable addition for low-band listening in suburban areas.

The article highlights the common absence of modern USB-C ports on handheld ham radios and the limited use of USB for power. The author, [jephthai], shares a solution involving a USB-C cable with power negotiation capabilities, allowing the radio to be powered by USB. By splicing Anderson power pole connectors onto the cable, the radio can now be conveniently powered by a USB battery bank, providing a practical alternative to traditional 12 V batteries for off-grid operations.

This post describes how the newish Power Delivery (PD) mode mobile powerbanks can be used to power a SOTA transceiver as well as keeping your other hiking devices charged.

Morse Walker is a web-based tool for amateur radio operators to practice CW skills. Inspired by Morse Runner by VE3NEA, it simulates pileup scenarios and contest formats like POTA, CWT, and SST. Modes include single-caller exchanges and basic contests, offering realistic experiences to improve speed, accuracy, and QSO handling. Ideal for contest preparation or honing activation skills, Morse Walker helps operators enhance proficiency in CW communication. Start your training today at MorseWalker.com

The author presents initial NEC model results for a reversible 40-meter Moxon antenna, comparing three distinct designs: a standard rectangle, a _W6NL short-tipped_ variant, and a T-hat configuration. All three models exhibit similar electrical performance, with gain figures around **5.5 dBi** and front-to-back ratios exceeding 20 dB. The primary differentiation among the designs lies in their mechanical construction and physical dimensions, which are critical for a 40-meter antenna. The rectangular Moxon requires robust support due to its element lengths, while the T-hat design offers enhanced structural integrity with slightly longer elements. The T-hat model is provisionally selected for further development, emphasizing the importance of mechanical considerations over minor electrical performance differences. Future work will focus on detailed mechanical design and construction aspects of the chosen T-hat configuration.

The TangerineSDR is a Modular Software Defined Radio Project with the following objectives, Development of SDR radios that allow experimentation, provide support to unaffiliated other groups, to provide hardware modularity, to allow varying performance, To allow users to experiment with differing configurations.

This guide explores the captivating hobby of shortwave listening (SWL), offering insights for beginners and enthusiasts alike. It covers key shortwave broadcast bands, essential tools like antennas and receivers, and practical tips to enhance listening experiences. Recommendations include budget-friendly SDR receivers, traditional radios like the TECSUN PL-680, and antennas suited for various environments. Additional resources, such as the World Radio & TV Handbook and online tools like Short-Wave.Info, are highlighted to help identify signals and maximize the enjoyment of SWL.

With some fantasy the circuit can be easily assembled on a small scrap of pre-perf board,and then fitted in the DB9 serial connector shell. The interface requires two NPN transistors and few more passive components.

Documents the design and construction of a **four-band Moxon beam** antenna, covering 20, 15, 10, and 6 meters. Author W7JMP shares his journey from initial research and computer modeling using 4NEC2 to the final on-air testing and optimization. The project aimed for gain over a dipole on 20 meters, with a budget under $500, including the antenna rotor. The design incorporates fiberglass spreaders and a single feedpoint, avoiding complex relay switching. The article details the selection of materials, assembly techniques, and the critical tuning process. W7JMP describes fabricating the hub, mounting spreaders, and attaching elements made from stripped THTN wire. A notable innovation is the use of a half-wave tuning stub with a loading coil for in-situ adjustment of the 20-meter reflector, optimized via remote S-meter readings using a webcam and smartphone. This method allowed for fine-tuning the **front-to-back ratio** without lowering the antenna. Initial testing revealed a dipole-like pattern, which was significantly improved after tuning, resulting in reported 2 to 4 S-unit front-to-back ratios and enhanced signal strength for DX contacts on multiple bands, including sporadic E on 10 and 6 meters.

The analyser has been written to support the full range of SDRplay SDR radios including the new RSP1B. The analyser is capable of resolution bandwidths of less than 1Hz with sensitivity better than -145dBm. In addition to being able to run five separate traces, the analyser offers the ability to capture screen shots, export data in a range of formats and includes a versatile marker system. The analyser includes a comprehensive user manual and offers a very useful addition to any workbench.

The 222 MHz Transverter project, based on Zack Lau's (W1VT) original July 1993 QEX magazine design, provides an IF of 28 MHz for both transmit and receive paths. Rick Bandla (VE3CVG) contributed supplemental notes and construction details, including modifications to achieve 10 mW output power from an initial 4 mW PEP. The design incorporates three distinct boards: a Local Oscillator (LO), a Transmitter (Tx), and a Receiver (Rx), with an estimated parts cost of just over $150 CDN, significantly less than commercial kits. Construction involves both through-hole and surface-mount components, with specific guidance on mounting MAV and MAR devices, grounding techniques, and component selection. The project details include parts lists, schematics for the LO, Tx, and Rx, and board layouts. Troubleshooting advice emphasizes sequential testing, starting with the LO, then Tx, and finally Rx, using a 194 MHz and 222.100 MHz capable FM handheld for signal tracing. Further enhancements are discussed, such as an optional Tx driver stage to boost output to 100 mW and the potential modification of a Motorola Maxor 80 PA for 222 MHz SSB/CW operation. The resource also covers practical aspects like power attenuation pads for IF radios (e.g., FT817) and considerations for enclosure design, including repurposing a Maxor 80 case. Performance reports indicate successful 70 km contacts with only 4 mW output.

Explaining ARRL Technical Reviews of Radios a brief tutorial on radio testing. The ARRL Lab tests radio equipment according to standardized test procedures, using calibrated professional test equipment. Info on transmitter and receiver tests

Yu produces miniaturized amateur radio transceivers for portable usage. Yu designed and sold the FX-2, FX-4a, and FX-9A. Other products includes the FX-4C, an 80 m through 10 m transceiver that fits in the palm of your hand.

The programming cable is intended to be used with a computer RS-232 port for programming radios and other devices. The main goal of this cable schematics is inverting signal levels.

A Go-box streamlines radio setup for temporary operations. Detailed guidance is provided on constructing a KX3 Go-box based on Radioset-go products. Emphasizing cooling, it incorporates silent fans and a temperature-controlled system. Wiring complexities, power considerations, and battery installation are covered. The Go-box offers a neat solution for field days and temporary setups, improving the efficiency and portability of the Elecraft KX3.

This article explores the conventional wisdom about antenna height in amateur radio operations, challenging the common belief that "higher is always better." Through practical examples and computer modeling, it examines how low-height antennas like Beverage antennas, VP2E, and End-Fed Half Wave (EFHW) configurations can perform effectively in various scenarios. The analysis includes radiation patterns and efficiency considerations for antennas at different heights, particularly focusing on portable operations. The article demonstrates that while height affects antenna performance, lower installations can still provide practical and efficient solutions for specific applications, especially in portable and QRP operations.

Integrating a _Software Defined Radio_ (SDR) into an existing ham radio setup involves connecting it with a standard transceiver (TRX), power amplifier (PA), and antennas. The core component is a splitter box that facilitates the connection between the TRX and the SDR, allowing for simultaneous operation without modifying existing equipment. In receive mode, the splitter ties the antenna inputs of both the TRX and a direct conversion receiver (DC RX) together. During transmission, the DC RX input is grounded via a fast telecom relay controlled by the transceiver's -SEND signal, incorporating a 10ms delay for safety. The splitter box includes a 3.7 dB input attenuator for impedance matching and acts as a protective fuse for the DC RX input. Ground loops are mitigated using common mode balun transformers, while the DC RX input is insulated with a broadband transformer. An audio switch box complements the setup, enabling users to listen to either the main transceiver, the SDR output, or both simultaneously. This configuration ensures noise immunity and safety, with the splitter housed in a screened box made from PCB material. On-air tests, such as the CQ WW 160m CW DX Contest, demonstrate the system's effectiveness, showcasing the SDR's ability to handle crowded band conditions with superior selectivity and dynamic range. The SDR's narrow bandwidth filters and waterfall display provide significant advantages, allowing operators to detect weak signals amidst strong interference. The integration of SDR with conventional radios offers enhanced operational flexibility and performance in challenging environments.

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.

HAMRS v2.52.0 provides a portable logging solution for amateur radio operators, supporting macOS, Windows, Ubuntu, Raspbian, iOS, and Android platforms. The software includes offline databases for POTA parks and US callsigns, facilitating logging without internet connectivity. It features ADIF import/export capabilities, enabling one-click uploads to QRZ.com. Rig control is supported through native _Hamlib_ and _FLRIG_ integration, alongside compatibility with _WSJT-X_ for digital modes. Recent updates in v2.50 introduced a QSO Map for visualizing contacts with band colors and filtering, real-time solar and HF/VHF propagation conditions, and a dedicated logging template for ARRL Field Day exchanges. An interactive US Band Plan displays privileges and sub-bands, while a live POTA Spots Map highlights the active park and offers license-aware spot filtering.

In a quest for reliable emergency power, the article discusses the necessity of accessible power solutions amidst blackouts and energy crises. It introduces the American-made Merlin Panther 100-watt solar briefcase and budget-friendly LiFePO4 batteries. The setup addresses the need for modular, renewable power solutions, balancing cost-effectiveness with functionality for various scenarios. The narrative emphasizes the importance of reliable power sources in unpredictable situations.

Ionospheric Propagation of Radio Waves in Action, How Do Ionized Layers Form to Enable Ionospheric Propagation of Radio Waves, the foundamental role of F layer, and the role of the other ionized layers

This page provides detailed information on the 4DX directional wire beam antenna designed by LZ1AQ, LZ1ABC, VK6LW, and DD5LP. It explains how to create this antenna for single or multiple bands using four separate sloping wires. The page includes instructions on achieving directionality, gains, and F/B ratios, as well as generating radiation patterns, VSWR charts, antenna currents diagrams, and Smith charts. It is a valuable resource for hams interested in building and optimizing their own directional wire beam antennas for improved performance and long-distance contacts.

What do amateur radio operators worldwide, think of their passion? What do we wish for? What are we frustrated about? How many of us are active, versus those that are taking a break? Do we have favorite radios, antennas, or even favorite cw paddles? Do we prefer one contest over another? The best way to find out is if we all participate in Ham Census. Join in and let all amateur radio operators know your thoughts "share your views" then you can find out what everyone else is thinking, in real time. Help shape the future of ham radio by participating in the world's most complete survey of amateur radio.

The page presents JRX, a virtual radio receiver interface written in Java that can connect to about 200 ham radio transceivers and receivers using the Hamlib library. It offers features like 200 read/write memories, a programmable scanner, and spectrum scope, making it easier to use than traditional radios. The article explains the benefits of virtualizing a radio with controls and highlights the advantages of using JRX, especially for radios requiring computer control. Author P. Lutus provides insights on the development of JRX and its improvements over previous virtual radio projects.

SWList iOS App, provides access to the EiBi list for discovering and identifying shortwave radio stations, curated by Eike Bierwirth. It offers four search methods: by frequency, radio band, station name, or language. Users can view detailed station information and map locations if available, with support for both light and dark modes.

World Radiosport Team Championship, Germany July 12-16 2018

This article help on explaining what you need to start with amateur radio. By using a local ham radio club station to purchasing second hand radio equipment and how to get help on installing antennas.

Dx-peditions365 let you follow the main DX-peditions on a dedicated calendar page that shows the schedule of all monthly expeditions, running dxpeditions and even shows the dxpeditions reported on their users logs or cluster spots. App available on apple iOS and Android.

Demonstrates ZeusSDR, a WebGL-native station console for _OpenHPSDR_ radios, including Hermes-Lite 2 and ANAN-class transceivers. The software integrates a 2D and 3D WebGL/WebGPU panadapter with click-to-tune functionality, alongside native FT8/FT4 and FreeDV digital voice modes, eliminating the need for external software like WSJT-X or virtual audio cables. It features a protected transmit chain with SWR-trip and TX-timeout, and supports _PureSignal_ linearization on Protocol 2 for enhanced signal quality. The console incorporates a broadcast TX chain with a noise gate, 10-band EQ, compressor, exciter, bass, reverb, and VST3/Audio Unit hosting for advanced audio processing. A comprehensive logbook is included, offering contact history, a 3D NASA globe, DX radar, and analytics for DXCC/WAS/grids, with ADIF and LoTW integration. Amplifier panels for RF2K-S, KPA500, and SPE Taurus are also provided. ZeusSDR supports both OpenHPSDR protocols (P1 + P2) and utilizes WDSP from Thetis. It is available for Windows, macOS, and Linux, with a public listening feature allowing others to view live waterfalls and use virtual receivers with Zeus DSP, including NR, NB, ANF, AGC, and filters. The software is open-engine, following the PowerSDR–OpenHPSDR–Thetis lineage.

CTR2-Mini is a small radio controller based on the Seeed Studios Wio Terminal. It can control many radios including FlexRadio 6000s. Multiple Minis can be used to control multiple slices on the Flex. It also has a special mode that allows two CTR2-Minis to control the Main and Sub VFOs on the FTdx101. An article on CTR2-Mini appears in the September 2022 issue of QST.

Learn how to build your own RF signal generator for aligning radios by following the modifications made to the circuit of an existing project. Explore the use of a common cathode varactor diode and a single center-tapped 24 VAC transformer to simplify the design. Discover alternative components like the MACOM 4ST079CK-287T varactor diode, which offers cost-effective solutions compared to unobtainable options. Find inspiration in modifying existing projects and gaining practical knowledge in electronics. Purchase the Nuts and Volts magazine for detailed schematics and a deeper understanding of RF signal generators.

The most basic form of repeater receives communication on one frequency and re-transmits it on a different frequency, a process known as duplex communication. This capability significantly extends the range of handheld and mobile radios, as repeaters are typically situated at elevated locations with high-gain antennas and greater transmit power. Repeaters commonly operate with FM modulation on the VHF (30 MHz – 300 MHz) and UHF (300 MHz – 3 GHz) amateur bands, which are ideal for portable and mobile devices. Access to repeaters is often controlled by a CTCSS or PL tone, an inaudible signal that prevents the repeater from retransmitting background noise. This mechanism ensures efficient use of the frequency and prevents illegal continuous transmission. Canadian regulations, for instance, require an Advanced amateur radio license and an available frequency within the band to set up a repeater, each assigned a unique call sign and transmit frequency. Configuring a radio for repeater use involves knowing the repeater's transmit frequency, its receive frequency offset (e.g., -600 KHz for VHF or +5 MHz for UHF), and the necessary CTCSS tone. The article references resources like Repeater Book for locating repeaters and provides practical examples for initiating and concluding a basic repeater session, emphasizing clear identification and concise communication.

The author explores enhancing the performance of a 7-meter fiberglass squid pole wire antenna for amateur radio. The wire, resonant at 10MHz, poses impedance challenges on various bands. Experimenting with direct coax feed and UN-UN transformers, the LDG Z11-Pro2 auto-tuner is found effective but may show deceptive SWR readings. The author employs adjustable UN-UN ratios and introduces a custom "porcupine" coil to optimize the antenna's efficiency.

The _MFJ-915_ RF Isolator, rated for 1.8-30 MHz and 1500W PEP, exemplifies the product range available from The Ham Shop. The inventory includes various antenna support ropes, such as 3/16" _Dacron Polyester Rope_ in lengths from 100 to 1500 feet, alongside a selection of cables for _SignaLink USB_ sound card interfaces. Specific SignaLink cables are offered for radios like the Yaesu FT-847 (SLCAB847), Yaesu HTs (SLCABVXY), and the Elecraft K3 (SLCABHTY). Additionally, the shop provides modular jumper cables and modules, including the SLMOD8RY for Kenwood/Alinco 8-pin round mic jacks and the SLMOD8RI for Icom 8-pin round mic jacks. The product line supports diverse station configurations, encompassing antennas, coax, baluns, dummy loads, duplexers, insulators, microphones, power supplies, SWR meters, and watt meters.

This page discusses the CLEFHW (Coil Loaded End-Fed Half-Wave) antenna, a portable variation of the popular EFHW design for ham radio operators. The article explains how the CLEFHW allows for backpack portable operation without the need for trees or poles, making it ideal for POTA activations and rapid deployment scenarios. The author details the design, optimization for 20m band, and compares efficiency to full-length wire antennas. Suitable for hams interested in portable antenna solutions and quick setup options for amateur radio activities.

Discover how to easily listen to amateur radio bands with insights from Frank SWL, an experienced radio enthusiast. This guide covers essential tips for tuning into frequencies between 10 meters and 160 meters using modern tools like Web SDR and Kiwi SDR. Learn about identifying callsigns, understanding Q codes, and optimizing your antenna setup for better reception. Whether you're a beginner or an experienced listener, this article provides practical advice for enhancing your radio listening experience in 2025.

Demonstrates the application of Software-Defined Radios (SDRs) as effective tools for conducting Radio Frequency Interference (RFI) site surveys. The resource details the methodology for capturing and analyzing RFI, specifically focusing on the 80-meter band over a 24-hour period. It outlines the setup of an SDR-based survey tool, utilizing software like _S-Meter Lite_ and _Spectrum Lab_ to visualize and quantify noise sources. The article emphasizes the SDR's wideband capabilities, which allow for comprehensive identification and documentation of RFI across broad frequency ranges, crucial for effective mitigation strategies. The analysis presents practical results, illustrating how continuous monitoring can reveal intermittent RFI sources that might otherwise go undetected. For instance, the survey identified noise peaks exceeding **S9+20dB** on 80 meters during specific hours, correlating with local appliance usage. The methodology provides a repeatable process for hams to characterize their local noise floor, enabling targeted RFI suppression efforts and improving weak-signal reception, particularly for DXing and contesting.

This page explores the world of Software Defined Radios (SDRs) in the context of amateur radio. It discusses how SDRs have revolutionized the hobby by reducing costs and enabling remote operation. The article provides ideas for projects and experiments that hams can undertake with SDR technology, highlighting the educational and experimental opportunities it offers. It also mentions specific examples of SDR projects like the Stoke on Trent SDR and SDR.HU. The content is aimed at amateur radio operators looking to explore and harness the potential of SDRs in their stations.

The article discusses the evolution of antenna designs, specifically focusing on the upgrade from the W7IUV rotatable Flag to the Waller Flag. Author Pierluigi Mansutti IV3PRK shares insights on modeling these antennas using EZNEC software, detailing their performance in noisy environments. The W7IUV Flag proved effective for receiving signals, while the Waller Flag, developed by NX4D and N4IS, offers improved front-to-back ratios but requires careful consideration of signal levels and noise management. The article emphasizes practical modeling results and interactions between different antenna setups.

OpenRTX is a free and open source firmware for digital ham radios. The firmware is designed with a top-down approach with the objectives of modularity, flexibility and high performance. Currently, it targets some Tytera Radioddity Baofeng digital radios

In this article, the current consumption for a selection of popular HF transceiver was examined to determine, via an on the field comparison, whether they were right for portable operation. The radios evaluated include the Yaesu FT-857D, Kenwood TS-590SG, Icom IC-7100, and Kenwood TS-480SAT. The measurements were taken beginning frok 5W in 5W increments up to 100W. The results showed that the Kenwood TS-590SG had the highest current use while the Yaesu FT-857D had the lowest. The current consumption of all radios increased as the power output increased.

This page contains detailed notes on repairing and aligning the Kenwood TS-440S HF radio. The author shares their experience repairing several TS-440S radios, highlighting common issues and repair techniques. The page also discusses parts availability, modifications, and the radio's performance for digital modes like FT8 and JT65. Aimed at ham radio operators interested in repairing and maintaining vintage HF radios, this page provides valuable insights and tips for working on the Kenwood TS-440S.

Boondock Echo offers a revolutionary communication experience with an internet-backed recording and playback device for two-way radios. It ensures clear, reliable communication in remote or challenging conditions. Key features include real-time recording, internet connectivity, seamless integration, playback flexibility, rugged design, and a user-friendly interface. Services include product training, hardware maintenance and repair, customization, and regular firmware updates for optimal performance.

This project details the development of a modular direct conversion (DC) receiver designed for experimental flexibility in amateur radio and HF signal listening. The mainframe integrates a diplexer, DBM, and AF amplifier, supporting interchangeable local oscillator and antenna filtering setups. A tunable passive HF preselector complements QRP Labs bandpass filters for enhanced signal reception. Utilizing a NanoVNA for precise tuning, the receiver achieves improved signal-to-noise ratios across amateur and non-amateur bands, making it a versatile platform for further RF experimentation.

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.

AllScan is a free and open-source web app for AllStar nodes that provides Favorites Management features, AllStarLink Stats integration, and connection monitoring and control functions. Shows your favorites in a Dashboard summary table with Keyed status, Connected Node count and other statistics. Continually scans the status of each favorite using ASL's Stats API data showing which favorites are active and have recently been active. Allows favorites to be connected with a single click (optionally automatically disconnecting any currently connected nodes first). Allows the Favorites Table to be sorted by Node#, Name, Description, Location, etc. Favorites can be added/deleted simply by entering the node# and clicking a button. These features finally give AllStar nodes similar memory management and scan capabilities that analog radios have had for decades. AllScan is mobile-friendly and optimized for ease of use on both small and large screens. AllScan follows the latest web development standards, with PHP, JavaScript, HTML, and CSS cleanly partitioned, runs on both ASL and HamVOIP, and is very easy to install, configure, and update.

The Icom series of radios from the IC-746 Pro on to the latest 7800 radios have a 4 memory digital voice and CW keyer built into the radio. This external Keypad, based on the official Icom circuitry can considerably help you on using the voice and cw keyer

The F6AOJ RX splitter project was created to split the antenna signal from an LZ1AQ receive loop to multiple receivers, such as radios or SDRs. The design is simple to build and effective. The splitter, mounted on the back of the LZ1AQ control board, provides two outputs—one for an Afedri SDR and another for a K3 transceiver. Measurements show a damping of -3.01 dB at 1 MHz and -3.10 dB at 30 MHz, with a low SWR (max 1.07 at 30 MHz and 1.4 at 60 MHz).