Search results

Learn about the ZRS QRP-808 kit system for hams from the 1980s. Discover the improved features of the QRP-808 compared to the QRP-805, including the electrical diagram and assembly instructions. Explore the nostalgic journey of building and tuning this iconic amateur radio station, as shared by experienced ham radio operators. See original photos and insights from enthusiasts like Janko S55WT and Mirko S52PC, offering a glimpse into the history of amateur radio technology. Access PDFs for detailed views and immerse yourself in the world of DIY radio equipment construction and tuning.

This documentation effort is intended to outline some of the primary steps to take in activating a SOTA Peak. It includes some of the planning steps, the activation, and post-activation steps. This outline is designed to serve as a general guideline for SOTA Activators

This page details the construction project of the 'Stone', a QRP double conversion superhet SSB transceiver for the 40m band. The project is based on a kit from Tim Walford, G3PCJ, and includes step-by-step instructions for building and testing each stage. The author has added enhancements such as a three digit frequency counter and an automatic gain control. The content is aimed at hams interested in DIY transceiver construction and includes technical details of the build process.

Detecting stray RF voltages on station grounds, chassis, and interconnecting cables is crucial for preventing program and hardware failures in the shack. This article details the construction and application of an LED RF V-probe, which offers significantly higher sensitivity compared to conventional neon lamp indicators. The probe leverages two specific properties of modern red LEDs: their ability to glow at microampere currents and their rectification capability at frequencies up to tens of megahertz. The design features a simple circuit with two LEDs, allowing for indication of both positive and negative RF voltage half-waves. The minimum detectable RF voltage is approximately 2 V, a substantial improvement over the 40-60 V threshold of neon bulbs. The resource illustrates the probe's physical construction on a PCB and provides a direct comparison demonstrating its superior sensitivity in detecting RF fields near a coil. Two operational modes are described: a non-contact mode for high RF voltages (above 15-20 V) and a direct-contact mode for measuring lower RF voltages, with a safety caution for the latter. Practical examples show the probe's use in analyzing RF voltage distribution across a radio station setup at 1.84 MHz and 24.9 MHz, revealing insights into common-mode current issues and the effectiveness of mitigation strategies like adding radials.

KISS703 is a 703 Hz narrowband digital mode for amateur radio, designed for simple, low-power operation without computers. A 500 Hz pilot tone ensures frequency alignment, replaced by unique tones for 37 symbols (letters, numbers, space). Built from common discrete components, it draws about 40 mA at 12 V, ideal for SOTA/IOTA use. The receiver uses amplification, wave shaping, and a pulse-counting frequency meter for manual decoding via a calibrated meter. Transmitter and receiver calibration involves marking meter positions for each tone, enabling fully self-contained messaging with minimal hardware in portable or fixed operations.

This project outlines a simple Lead Acid/SLA battery monitor, designed to alert users when battery voltage falls below 10.6V. The monitor, based on a PIC16F1827 microcontroller, checks the voltage of up to five batteries and triggers an alarm if any drop too low. The system operates in various modes, including self-test, monitoring, and alarm. This updated version improves upon the original 1999 design, offering a more modern microcontroller and extended functionality for workshop use, with minimal impact on battery charge.

The article "Icom IC7300 RTC Fix" details the meticulous repair of an Icom IC-7300's faulty real-time clock (RTC). The author and a friend, Nacho, discovered the RTC was gaining an unacceptable 11 seconds per day. Investigations revealed the Seiko Epson RX8803LC RTC was far outside its specified stability. Despite replacing the RTC and a burned pullup resistor, the transceiver still malfunctioned, leading to the replacement of the processor. Post-repair, the clock's accuracy improved significantly, now gaining only 1.4 seconds per month. This narrative underscores the complexities of electronic repairs and the satisfaction of resolving intricate issues.

MyWaveRecorder is a lightweight utility designed to capture and save any audio played on your computer. Whether it’s sounds generated by programs like CW_PLAYER, WX_PLAYER, MyWaveRecorder itself, your microphone, your sound card, or even streaming audio from the internet, this tool records them all with a single click.

The project details the construction of a small, portable **CW decoder** built around an Arduino Nano and an LM567 tone decoder circuit. It integrates an OLED display for output and is powered by a 1200 mAh Li-Po battery. The Arduino Nano is programmed with a modified version of the OST Morse Box firmware, originally based on Budd, WB7FHC's work, provided as a HEX file for flashing. The LM567 output connects to Arduino pin D2, while pins A6 and A7 are grounded due to the absence of potentiometers, simplifying the circuit. Standard I2C connections are used for the OLED: SDA to A4 and SCL to A5. The entire assembly, including the Arduino, OLED, and decoder circuit, is mounted on a perfboard to fit precisely within an old cassette tape box. This design emphasizes portability and compact form factor. Parameters for the decoder can be adjusted using a dedicated Windows Control program, offering flexibility in operation. The resource provides practical insights into adapting existing firmware for specific hardware constraints and achieving a self-contained, battery-powered **Morse code** decoding solution.

This page provides a detailed guide on the J-pole antenna, an end-fed half-wave antenna matched to the feedline by a quarter-wave transmission line stub. It covers the characteristics, construction materials, feeding options, and mounting considerations for optimal performance. The information is useful for hams or amateur radio operators looking to build and set up a J-pole antenna for improved transmission and reception.

Provides access to a robust DX cluster node, G6NHU-2, running DX Spider software, which facilitates real-time amateur radio contact spotting across HF bands. This service is engineered for high reliability and low latency, ensuring rapid dissemination of DX spots from a global network of interconnected nodes. It features multiple redundant links to prevent data loss and maintain continuous operation, even if individual connections drop. The cluster integrates directly with the Reverse Beacon Network (RBN), allowing users to enable or disable skimmer spots for specific modes like CW, RTTY, FT8, and FT4. It also offers an extensive one-year spot history, significantly longer than most other DX clusters, which typically retain only a month of data. The node supports various lookup commands for callsign information, beam headings, QSL routing, and FCC database lookups, enhancing operational efficiency for DXers and contesters. Additionally, it permits self-spotting, a feature increasingly relevant in modern contests, and provides detailed instructions for connecting popular logging software such as N1MM+, HamRadioDeluxe, MacLoggerDX, LOG4OM2, Logger32, and N3FJP's Amateur Contact Log.

Enables digital radio transceivers to function as versatile data communication nodes, supporting applications like _Reticulum_ networking, messaging with Sideband, and acting as a LoRa-based KISS-compatible amateur radio TNC. This firmware transforms off-the-shelf development boards into powerful, long-range data radios, facilitating robust communication over significant distances, potentially achieving **hundreds of kilometers** with optimal setups. It supports a range of hardware, including unsigned.io's Handheld RNodes (v2.x and v1.x), LilyGO T-Beam v1.1, LilyGO LoRa32 (v2.0, v2.1), and Heltec LoRa32 v2 devices. Compatibility extends to transceiver modules utilizing Semtech SX1276, SX1278, SX1262, SX1268, and SX1280 chips, provided they have an SPI interface and exposed interrupt pins. Installation is streamlined via the `rnodeconf` utility, part of the `rns` package, simplifying the flashing process for users. The project operates under the GNU General Public License v3.0, promoting open development and user freedom. It encourages community involvement in building and deploying RNodes for various purposes, from personal communication to establishing resilient, decentralized networks. The firmware's design emphasizes flexibility, allowing for diverse configurations to suit specific operational requirements.

Demonstrates the construction of an active loop converter specifically designed for the Low Frequency (LF) bands, addressing common localized noise interference in LF reception. The design integrates a sharply tuned circuit and a tuned loop antenna, utilizing the loop as the sole tuned inductive element. By applying positive feedback, the converter significantly increases the loop's effective Q, achieving factors between 1000 and 2000, which sharpens tuning and reduces noise. The circuit employs an _NE602_ mixer stage, feeding its output to an HF receiver, with a crystal-locked local oscillator at 4 MHz. A 20-turn, 0.8-meter square loop antenna with 500 uH inductance is detailed, connected via 2 meters of figure 8 flex cable. The converter offers three selectable frequency bands: 195-490 kHz, 150-220 kHz (including the New Zealand amateur band), and 128-160 kHz (covering the European amateur band). Performance measurements indicate an effective 3dB bandwidth of approximately 100 to 200 hertz at 200 kHz. The article provides insights into component selection, including an _LF353_ op-amp and a trifilar wound transformer on a ferrite core. Sensitivity figures are presented, showing 7.5 uV of converted output per 1 uV/meter signal strength into a 50-ohm load, or 37.5 uV into an _FRG7_ receiver, highlighting its capability to extract weak signals from noise.

This page discusses the construction and use of a low pass filter for MF/LF reception, specifically for the 630 meter and 2200 meter bands. The author, KA7OEI, shares technical insights and practical advice related to amateur radio, with a focus on improving reception in the low-frequency bands. This resource is useful for hams interested in building their own filters to enhance their MF/LF reception capabilities.

The W6PQL 23cm Beacon Project describes a **1296 MHz** beacon designed for microwave propagation studies and equipment testing, capable of 30 watts output. It utilizes a PIC 16F628A microcontroller to generate CW and FSK keying for a crystal oscillator, followed by a series of frequency doublers and triplers to reach the target frequency. The final power amplification stage employs a Mitsubishi M57762 module, providing a robust 10-watt RF output. The design emphasizes stability and reliability for continuous operation, with the microcontroller code, written in assembly, provided for customization of the beacon's callsign and message. Originally located in CM97am and aimed at 140 true, the beacon used four 4-foot Yagis stacked vertically for a total ERP of 3kW. The article includes schematics, parts lists, and construction notes to guide builders, along with antenna pattern measurements. Although the beacon itself is no longer in service as of August 2010, the detailed documentation remains a valuable reference for amateur radio operators interested in building similar **microwave** projects or understanding beacon operation.

HamHAW (Ham Health and Welfare) is a pioneering platform that bridges the gap between emergency communication and community welfare. By leveraging the extensive ham radio network, we help locate missing persons and coordinate welfare checks during disasters when traditional communication infrastructure fails. Hamhaw mission is to provide emergency communications support to the public so those inside an emergency area can communicate their status and needs to authorities and the public at large.

We are a non-profit amateur ham radio association located in the rural Lakes Region of New Hampshire. We actively promote 2 way radio, also known as ham radio. Our members are friendly and knowledgeable. If you are a first time visitor and are curious about this great hobby, we provide testing for ham licenses, have fun get-togethers, and are ARES affiliated for emergency communications. We also are home to 6 repeaters. Three are located on Bennett Hill in Ossipee, one on Mt. Rowe in Gilford and two on New Durham Ridge, New Hampshire.

In the realm of amateur radio, the need for a reliable platform to exchange equipment is crucial. _Ham Radio Swop Shop_ addresses this by providing a dedicated online classifieds service for South African amateur radio operators, SWLs, and RAE holders. The platform allows users to list a wide range of items, including _HF_ and _UKW_ transceivers, antennas, and surplus parts. Each listing can include detailed descriptions and multiple images, facilitating informed transactions. The service operates with a clear policy that commercial entities may participate, provided their postings are not excessive and are clearly marked. This ensures transparency and maintains the platform's focus on individual users. Importantly, the administrator, ZS1AI, does not mediate disputes or assume responsibility for transaction outcomes, emphasizing the need for users to conduct their own due diligence. Distinctively, the Swop Shop functions independently, unaffiliated with any external organizations, fostering a self-regulated marketplace. This independence ensures a neutral environment where the South African amateur radio community can freely buy, sell, and swap equipment. The platform's commitment to neutrality and user responsibility makes it a unique resource for radio enthusiasts in the region.

AA DX Group was founded in March 1, 1974 in The Netherlands. Our members was more than 10000 from all over the World. Because during the years many of our members became "Silent Keys" or they are not active on the air anymore, we deceide to make new fresh group and to delete all old database. So, we are the new - old Alfa Alfa DX Group and you are welcome to be our member. We make avaiable all Alfa Alfa numbers for new and active CB members and SWL ( Shrot Wave Listeners ). Alfa Alfa World Wide DX Radio group is looking or ACTIVE CB Operators and SWL stations ! The New AADX team in in 2024 Main base in 178AA000 178AADX000 in Belgaria

108 Alfa Tango 101 - My personal CB Radio and 11m DX homepage.

The Alfa Alfa (AA) DX Group, established on March 1, 1974, in the Netherlands, is presented as the pioneering Dutch 27mc DX group. It details the group's historical significance, particularly its revolutionary use of the '000' club callsign (19AA000) which influenced international 11-meter group callsign structures. The resource outlines the group's re-establishment in 2024, inviting new active CB operators and _Short Wave Listeners_ (SWL) to join its ranks, emphasizing a free worldwide membership model. Membership requirements are specified, focusing on active participation with an assigned AA callsign. The group provides QSL card management services, with options for direct QSL requests requiring **3 USD** and a Self-Addressed Envelope, or **4 USD** via PayPal for expenses. It also mentions upcoming initiatives like an _AA DX Contest_ and an award program, with sections for certificates and plaques currently under construction. The site also lists useful CB resources, including an 11M DX Cluster and an 11M Callsign Database, and provides contact information for the founder, 19AA001 Mr. Theo, and the Worldwide QSL Manager, 178AA001 Mr. Emil, based in Bulgaria.

For amateur radio operators seeking resilient, off-grid communication, the _MeshCom_ firmware provides a robust solution for text-based messaging over a mesh network. Utilizing LoRa modulation and the APRS protocol, this firmware is designed for low-energy consumption and cost-effective hardware, primarily operating in the 70cm band. Nodes, identified by amateur radio callsigns, can send short text messages to all participants or directly to specific callsigns, functioning as repeaters to extend network reach. The system supports automatic status and position messages, with optional sensor data for WX-Data and Telemetry. MeshCom nodes can be configured as gateways to HAMNET or the internet, enhancing connectivity options. The project emphasizes a self-building and self-healing mesh network architecture, crucial for emergency communication scenarios. Operating frequencies include 433.175 MHz (EU, USA, Africa), 439.9125 MHz (UK), and 433.925 MHz (Norway). The firmware is compatible with hardware platforms such as ESP32/LoRa modules, RAK-WISBLOCK, and ESP32-DEV4/E22-LoRa, offering a flexible deployment for various amateur radio applications.