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Arduino/ATtiny Based (Ham Radio) ICOM CIV to Yaesu BCD Band Decoder. Build a ICOM CIV to Yaesu BCD Band to automatically band switch the Yaesu Quadra Amplifier.

Ground Station offers real-time satellite tracking and radio communication capabilities, primarily for amateur radio operators engaged in satellite operations. It utilizes **TLE data** from sources like CelesTrak and SatNOGS for precise orbital prediction and integrates with various SDR devices, including RTL-SDR, SoapySDR, and UHD/USRP radios, to receive live signals. The software provides automated antenna rotator control and **Hamlib-compatible** rig control with Doppler correction, crucial for maintaining signal lock on fast-moving LEO satellites. It supports IQ recording in SigMF format and decodes several digital modes such as SSTV, FSK, GFSK, GMSK, and BPSK with AX25 USP Geoscan framing. Dedicated interfaces are available for satellite tracking, SDR waterfall displays with live transcription and packet decoding, and telemetry packet viewing. Users can manage TLE data synchronization and SDR hardware, along with browsing decoded outputs through an integrated file browser. An observations dashboard and DSP topology view further enhance the operational experience, providing comprehensive tools for monitoring and analyzing satellite passes.

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.

Extend frequency coverage on the Kenwood TS-680S transceiver

The Specan is actually a very simple but robustly built receiver. it is, in essence, a double conversion superhet receiver with 112 Mhz and 12 Mhz Intermediate frequencies. The first mixer uses an Si570 as the local oscillator. The Ardiuno that controls the Specan is a very flexible microcontroller board that you can program in simple C language

Operating the FT-817 from various types of batteries, such as Alkaline Cells, NiCd or NiMH rechargeable batteries. An useful article that compares usage of different types of batteries for the Yaesu FT-817

This page by Basu (VU2NSB) presents automatically rendered antenna bearings with geodesic paths projected on a rectangular map. ch geodesic great circle path displayed on the map originates from your location that is derived from your Internet IP address. Therefore the Antenna Bearing Geodesic Map generated below should be accurate and relevant to your physical location (QTH). This map is an alternative to the Great circle Map.

DX8DX Taganak Island (OC-225), Bongao Island (OC-174) & Tawi Tawi Island (OC-174) April 2013

Phased array antennas are composed of multiple individual antenna elements that can have their phase and amplitude controlled to steer the main beam direction in real-time. They are used in radar, communications, and electronic warfare, and offer improved gain and reduced side lobes. A comprehensive document on Phased Arrays include techniques to increase the Antenna Gain and change the Radiation Pattern

A Case For Thunderstorms Causing Sporadic E on 6 Meters. In Propagation and Radio Science, Eric Nichols explains one possible mechanism is thunderstorms that are strong enough to break electrons free forming a cloud of free electrons.

February 6th to February 18th, 2019, International DXpedition to the Sultanate of Brunei, A low-bands-focused DXpedition

VFC has grown to become the national leader in the lightning protection industry. Protecting facilities and equipment from lightning and transient current by designing and installing lightning protection, grounding, surge protection and lightning warning systems.

Getting started with a fun low-cost analog/DMR radio

This project delves into the development of a compact WSPR beacon, building on earlier experiences with weak-signal modes. Inspired by QRP Labs kits and modified open source designs, it integrates a Si5351 frequency generator, GPS module, and class E PA for efficient operation. Extensive optimizations—addressing drift, heat management, and power stability culminated in a portable, serviceable device. The beacon offers insights into propagation while minimizing reliance on main station equipment. Lessons learned highlight the importance of careful component selection and iterative design improvements for robust amateur radio experimentation.

This comprehensive three-part guide examines baluns (balanced-to-unbalanced devices) and their critical role in ham radio antenna systems. The author explains how baluns prevent common-mode currents on feedlines, which can distort radiation patterns and cause unwanted RF in the shack. Various balun types are analyzed, including coiled coax chokes, ferrite-core designs (W2DU), and toroidal-wound versions (Guanella/Ruthroff). Construction techniques for 1:1, 4:1, 6:1, and 9:1 current baluns are provided with practical guidance on wire selection, winding methods, and ferrite core properties. The article emphasizes that proper balun implementation is essential for optimal antenna performance, especially with directional arrays.

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.

This blog post by VE3VN discusses the design and performance of a 40-meter reversible Moxon antenna. The antenna provides coverage between southeast to west by default, with the ability to reverse for coverage from east to northwest. The post explains how the antenna performs well in various directions, focusing on the Caribbean, South/Central America, the US, and Europe. Detailed measurements and design considerations are shared, highlighting the accuracy of the model and the critical importance of coil inductance. The post also mentions the use of NEC5 for accurate modeling. Overall, this detailed discussion provides valuable insights for ham radio operators looking to optimize their antenna setup.

This Arduino project explores long-range RF communication using EBYTE E32 1W LoRa modules (either E32-915T30D or E32-900T30D) paired with ESP32 microcontrollers featuring OLED displays. The setup leverages the modules' Semtech SX1276 chip with amplifier to achieve up to 1W transmission power—significantly more than the chip alone provides. Unlike other LoRa implementations, these modules include a microcontroller that simplifies interface through UART rather than SPI. The documented implementation includes proper wiring between components and Arduino code that configures the module, displays received messages on the OLED screen, and transmits messages every two seconds while keeping power consumption manageable.

An online inductive reactance calculator, accepts as input Frequency and Inductance

The document provides a detailed modification guide for the Zetagi HP201 SWR Wattmeter, converting it for HF amateur band usage. It replaces the original circuit with a Tandem Coupler based on the Sontheimer and Frederick directional coupler patent, enhancing accuracy and sensitivity. Key components include Murata toroid cores, scaling resistors, and a new calibration process. Challenges and solutions during the modification process are discussed, ensuring linear results across 160-10m bands. This guide also includes calibration instructions and theoretical insights into the coupler's operation.

How to repair and calibrate a used Bird model 43 wattmeter.

Four _Headway 38120_ LiFePO4 cells form the core of an 8AH 12V battery pack, designed for reliable emergency and field power in amateur radio operations. These batteries offer significant advantages over traditional lead-acid types, including a lifespan up to **10x** longer in charge/discharge cycles, lower internal resistance for faster recharging, and a flatter discharge curve that maintains voltage stability during use. Their inherent safety, being a flame-retardant technology, makes them a preferred choice for portable applications. Proper configuration, including parallel/serial setups, and careful charging/discharging protocols are crucial for maximizing battery life. Each cell has a nominal voltage of 3.2 volts, with a maximum charge voltage of 3.65 volts. A Battery Management System (BMS) is highly recommended to prevent overcharging or deep discharging, safeguarding the cells. The project emphasizes safety, noting the batteries' high short-circuit capacity of **200 AMPS** and the critical importance of incorporating an inline fuse between the battery pack and the load. Components like the battery holder, buss bars, and a suitable case are also detailed.

The guide details setting up a comprehensive HF packet BBS using linBPQ on a Raspberry Pi. Exploring linBPQ's versatility and community support, the author emphasizes its legality considerations and cross-platform accessibility. Configuration files for linBPQ, including bpq32.cfg, chatconfig.cfg, and linmail.cfg, are explained along with the systemd service setup. The linBPQ Web Management Interface and future setup for QtTermTCP are also discussed for a complete packet BBS experience.

Home made free utility can be useful to monitor which is the RX and which is the TX VFO and the correspondig frequencies. Works with Yaesu FT-5000.

The IARU Region 2 has established this voluntary band plan to better organize the use of our bands efficiently. To the extent possible, this band plan is harmonized with those of the other regions.

The QRP Cluster provides a dedicated platform for _QRP_ (low power) amateur radio operators to self-spot their on-air activity. This web-based service allows users to post real-time information about their current operating frequency, modulation mode, equipment used, and transmit power. It facilitates QRP-to-QRP contacts and helps other low-power stations locate active QRP signals across various bands. Unlike general DX clusters, the QRP Cluster focuses exclusively on low-power operations, fostering a community for QRP enthusiasts. It enables operators to share details such as **5 watts** or less output, often specifying antenna types or unique portable setups. The platform supports the discovery of QRP stations for casual QSOs, contests, and award hunting, enhancing visibility for stations that might otherwise be overlooked on higher-power clusters.

This project describes the construction of a W3HH (T2FD) antenna for HF bands (3-30 MHz). While less efficient than a tuned dipole, it offers broad frequency coverage with a maximum SWR of 3.4 and reduces QRM (noise) significantly. On the 80-meter band, it shows slightly weaker signals than a dipole but with improved signal-to-noise ratio. The design includes non-inductive resistors, a 13:1 balun, and a "frog ladder" transmission line. Though not a high-performance antenna, it is compact and versatile, making it ideal for wide-band HF communication. Article in French

Radio Frequency Interference (RFI) has always been a source of concern for the Radio Amateur. Until the recent introduction of complex circuitry in the home, our communications gear has been the main source of potential RFI. In this computerized age of ours, increasingly complex and sensitive receivers are being barraged by these and other sources of RFI.

The 8m ISM band, a unique frequency range between 10m and 6m, holds potential for amateur radio enthusiasts, yet it remains largely unallocated. This spectrum offers fertile ground for research and self-training. The author's experience with low-power transmissions and WSPR testing highlights the band's capabilities and the need for a narrow, speech-free amateur allocation to encourage experimentation. Discover the world of 8m ISM radio exploration and its future possibilities.

The Dipole Bazooka Antenna for 40 meters is a popular choice among amateur radio operators. Its design allows for easy construction using materials like RG58 coaxial cable and PVC. Measurements are calculated using specific formulas; for instance, at a frequency of 7,100 MHz, the total length is approximately 19.74 meters. This antenna offers a performance range of 97% to 99%, with an impedance of 49 to 52 ohms. Additionally, it can handle up to 1 kW of power and requires no modifications for connection.

Explore the design and testing of a cage dipole antenna for 6 meters. Through innovative construction, witness a remarkable 77% increase in bandwidth and improved impedance characteristics.

Useful memory and settings manager to backup and restore all the 177 menu setting of the FT-5000

The Kenwood TS480SAT/HX firmware upgrade guide, procedure, tools required, software needed to upgrade the transceiver firmware and some hints.

Unveil the secrets of efficient Magnetic Loop Antenna control systems, eliminating the hassle of frequent retuning. With real-time tracking and compatibility with various transceivers, including popular models from Elecraft, ICOM, Kenwood, and Yaesu, this controller ensures seamless frequency adjustment. Explore its high-resolution stepper motor and versatile communication capabilities, revolutionizing amateur radio operation.

A quick guide to install direwolf, bpq and jnos on a Raspberry Pi. By following the instructions in the examples listed on this page, you should get it to work.

A two tone generator is an essential test gear made with just four transistors that helps you evaluate your amplifiers, mixers, receivers for distortion. Distortion makes all the difference between a pleasant receiver and a horrible sounding one, between a clean transmitter and bad, splattering one on air.

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.

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.

PH0NO conducted field tests comparing a mobile antenna (DX-UHV) to an end-fed half-wave wire. Results on 20m showed the end-fed wire outperforming the mobile antenna, with a significant difference in signal strength. On 40m, the end-fed wire surpassed the mobile antenna in spots and reach. While the mobile antenna is more practical, the end-fed wire offers superior performance. Further testing is planned.

Online calculator that will convert power entered in milliwatts to dBm. Includes a quick mW to dBm conversion table

LZ1AQ describes a versatile QRP antenna tuner that switches between Pi and Tee configurations with a single toggle. Using two variable capacitors and a seven-switch stepped inductor providing 128 increments (0.16 to 18.7 uH), this compact design handles 3.5 to 28 MHz with excellent matching range. The Pi mode works best for certain impedances while Tee mode proves more universal, matching loads the Pi cannot. Built in a plastic enclosure using salvaged radio capacitors, the tuner operates reliably up to 100 watts with proper antennas, though it's optimized for QRP service with random wires.

DIY project of a QRP Balun. Using a high permeability ferrite rod and an old B&W dipole center insulator, he constructs a choke type balun for QRP use. The balun aims to create as much inductance as possible at HF, offering a high impedance to common mode currents

Stop EMI RFI Interference in Off Grid Solar PV Systems, in this article the author provides hints on tracking down the EMI or RFI source, shielding and grounding in order to eliminate interferences on the whole HF and VHF ham radio bands

The Homebrew uSDX SDR TRX is an experimental transceiver primarily designed for CW and Digital modes due to limitations in meeting FCC requirements for SSB. Developed from the QRP Labs QCX, it incorporates advanced SDR features while utilizing an 8-bit ATMEGA328P. The µSDX community fosters open-source development with various design streams and versions, encouraging collaboration and sharing among enthusiasts.

This page provides updated data and statistics about United States amateur radio operators, including historical totals, demographics, and geographic distributions. It also explains the Amateur Radio Service, highlighting its role in promoting wireless communication and technological advancements. The page is a valuable resource for hams interested in understanding the current landscape of amateur radio in the United States.

Inspired by Heathkit, author aimed to enhance his Yaesu FT-817 with audio and RF processing. Design goals included a compact enclosure, PCB simplicity, matching jacks, a visual meter, and a built-in signal generator. Despite challenges in finding a suitable compressor IC for a 5V DC mic jack, he chose the Analog Devices SSM2165/2166 series. Prototyping with a solderless breadboard, author planned a PCB layout for its versatile performance in communication use.

This project addresses the need for a 50 MHz Amplifier providing substantial power for Australian "Advanced Licensees" permitted to use 400W PEP in the 52-54 MHz band. In regions limited to 100W PEP due to TV channel usage, this initiative aims to enhance power output for transceivers with lower capabilities on the 6m band.

A course on fractals antennas theory provided by La Ecole nationale superieure de techniques avancees in France. Course is in French.

Discover how the author, KK4Z, has perfected his Frankentenna over the years for portable operations, especially for Parks on the Air (POTA). Learn about the components sourced from different companies like Buddipole and Chameleon, allowing for versatility as a vertical antenna, endfed with a counterpoise, or even a dipole. The article also covers specific tweaks and modifications made to enhance performance. Ideal for hams looking to optimize their portable station setup with a reliable and lightweight antenna solution.

Automatically input GPS location data from an Android device to the transceiver, Compatible with IC-7100, IC-9100, IC-9700, ID-4100A/E, and ID-5100A/E.