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USA Amateur Radio Repeaters Directory, 2m and 70cm bands.

The earliest known historical record of the name Uzice is found in a document in the Ragusan archives, dated October 9th, 1329. In memory of this date, October 9th is now Uzice City Day. Earlier settlements in the vicinity date back to the Neolithic times. Throughout history, this area has been at a crossroads connecting economies and cultures North-South and East-West. To this day, Uzice is an important economic, industrial and cultural center. Award is active from October 1st to October 16th each year. To win you have to collect enough points making contacts (QSOs) with amateur radio stations which base locations are in the Uzice City Area.

The *SPACE* Amateur Radio over Internet Protocol (RoIP) system offers public audio transmissions from NASA Mission Control and astronauts, primarily for educational purposes. This service streams NASA public media sources, including *Artemis II* and the ISS public audio channel 2 feed, which predominantly features English communications. Astronaut activities on the ISS typically occur between 0700 UTC and 19:00 UTC, with transmissions most common during early mornings USA time, alongside special events such as launches or spacewalks. Users can connect to the live stream via EchoLink to the *SPACE* conference, via IRLP to the 0100 experimental reflector, or via Allstar to node 516221. EchoLink connections utilize the GSM CODEC, while IRLP and other connections default to uncompressed or u-law CODEC. The service notes that long periods of silence are common, and NASA audio sources can be periodically unavailable or noisy. Daily recordings of these transmissions are published at space.rfnet.link/recordings/, available as .ogg audio files for direct playback or .m3u8 playlist files for network streaming in applications like VLC. Each playlist file provides a list of timestamped audio transmissions, allowing users to review specific segments of interest.

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

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.

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.

This page delves into the debate surrounding the End-Fed Half-Wave (EFHW) antenna, exploring whether it is truly a multiband antenna without the need for a tuner. The author investigates the claims and criticisms surrounding these popular antennas, discussing their resonance on various bands and their efficiency for DXCC achievements. The content is valuable for hams interested in understanding the capabilities of EFHW antennas and their performance across different HF bands, with a focus on practical usage and real-world results.

The article discusses the use of SDR# (SDR SHARP) software for SDR receivers, highlighting its Band Plan feature that visually represents RF spectrum allocations. The author modified SDR# to display detailed IARU HF band plans, creating three XML files for different IARU regions. These files include various operational modes and specific frequency allocations. Despite potential errors, the modifications aim to enhance the usability of SDR# for ham radio operators. The article includes references and download links for the XML files and IARU band plans.

In an innovative analysis, Michael G7VJR employs NeuralProphet to predict ham radio modes' usage trends. The AI model, leveraging deep learning, forecasts a steady FT8 dominance, with slight declines in CW and Phone activities. This approach simplifies statistical predictions, showcasing the power of AI in understanding complex patterns and facilitating insightful time series projections. Access the freely available Club Log data for continuous exploration.

open890 is a web-based UI for the Kenwood TS-890S amateur radio, and features good usability, clean design, and high-speed bandscope/audio scope displays, among other features not available either on the radio itself, or in the ARCP remote control software. It is currently only designed to interface with the TS-890 via a LAN (or wifi) connection, and not a USB/serial connection. It may work with the TS-990, as the command set is very similar, but is currently untested.

The UV-K5 HF Fullband receive firmware version 0.3 introduces enhanced SSB capabilities using the SI4732-A10 chip. Released separately from UV-K5 CEC firmware, it offers improved HF reception, mode changes, frequency fine-tuning, and user modifications. New PCB designs and detailed usage instructions are included.

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 discusses a simple receiver protection device designed by Matt Roberts for hams. The article details the purpose, construction, and usage of the RF clipper, providing useful information for ham radio operators looking to protect their equipment from RF overload. The content is practical and informative, offering a solution to a common issue faced by hams.

This tutorial demonstrates how to charge laptops or tablets, like the Microsoft Surface, using off-grid 12-volt batteries typically used for ham radio gear. The guide highlights the importance of selecting a reliable USB-C PD adapter, recommending a 15V, 60W minimum with 5–20V, 3–5A capability. Featured tools include a 100W USB-C adapter and a USB multimeter for monitoring power usage. The video also explores the compact, efficient Power Queen 50Ah LiFePO4 battery for portable power solutions.

The Smith Chart, named after its inventor Phillip H. Smith, is a graphic tool used to solve transmission line problems in the field of ham radio operations. By using the Smith Chart, ham radio operators can determine the feed point impedance of an antenna, design impedance-matching networks, and optimize power transfer between a source and its load. The chart consists of resistance and reactance circles, providing a visual representation of complex mathematical relationships related to transmission line operations. Understanding and utilizing the Smith Chart is essential for hams looking to enhance the performance of their RF circuitry.

Operating a web-based DX cluster, this resource presents real-time amateur radio DX spots, facilitating contact logging and propagation analysis. It leverages the Spiderweb platform, offering users the ability to filter DX spots based on various criteria, including inclusion and exclusion rules. The interface integrates directly with QRZ.com for immediate callsign lookups, displaying flag icons for geographical context, and provides charts and statistics derived from spot data. Further enhancing its utility for DXers and contesters, the cluster includes direct links to MUF (Maximum Usable Frequency) maps and HamQSL solar condition reports. These external data sources provide critical propagation insights, assisting operators in making informed decisions about band selection and operating times. The service also offers Telnet access at dxc.sv5fri.eu:7300 for those preferring a command-line interface.

This software enables remote monitoring of the Kenwood TS-590SG HF transceiver. Based on a lightweight, text-based monitor was developed using Python and ncurses. It connects via rigctld, displaying key metrics like frequency, power, SWR, and TX/RX state with minimal data usage. Ideal for low-bandwidth remote operation, it works over SSH or mobile data. The software is open-source under GPL v3.

This is a 50 MHz WebSDR receiver, located in Ashford, CT, USA FN31VU using a deltaloop turnstile horizontally polarized omnidirectional antenna.

Established in 2018, the Long Island CW Club aims to revitalize Morse Code (CW) usage among amateur radio operators. Despite the FCC's removal of CW as a licensing requirement, the club observes a growing interest in learning and mastering the code. Through online video conferencing, the club offers CW training classes catering to various skill levels, fostering a vibrant community of enthusiasts engaged in diverse ham radio activities worldwide.

This page provides a detailed comparison between the Zero Five and Gap Titan ham radio antennas. The author shares their personal experience with both antennas, highlighting pros and cons for each. They discuss aspects such as ease of assembly, customer service, tuning capabilities, performance on different bands, and the need for grounding and tuning. The comparison aims to help readers make an informed decision on choosing the best antenna for their needs, based on real-world usage scenarios and feedback.

This project describes a high-performance EME antenna array consisting of two home-designed 9-element Yagis, each about 2.5 wavelengths long, combined into a 25-ohm system and matched to 100 ohms using 9/4λ sections of 50-ohm coax. The array supports rotatable polarity from 0° to 180°, allowing both horizontal and vertical polarization to optimize moonbounce performance under varying conditions. Despite operating for years without a balun—something another designer called “disastrous”—the system has delivered strong results, including copying very weak DX such as VK3KH at about -25 dB with only 120 W (around 2 kW ERP). The builder continues to refine the mechanics, having installed new gear motors and an upgraded follow-up control system in 2011.

Electronic Component Distribution has a wide-ranging inventory of electronic items. We are Board Level Components and Electronic Part Types supplier in the USA.

Callook provides a **USA amateur radio callsign lookup service** with data current as of March 25, 2026. The platform allows users to search for valid callsigns and retrieve detailed information, including geographic coordinates sourced from the Bing Maps API. A mathematically calculated **grid square** is derived from these coordinates, though accuracy is not guaranteed due to reliance on external services. The service supports multiple access methods, including a browser search plugin, direct API access with a reference, and plain text output for integration into other applications or scripts. This tool facilitates rapid identification of US amateur radio operators, offering an alternative to other callbook services. Its API access enables developers to integrate callsign lookup functionality into custom applications, streamlining data retrieval for logging software or contest management. The direct presentation of FCC data, combined with grid square calculation, assists DXers and contesters in verifying contact information and location details during on-air operations.

This page presents the K4 S-Meter Recorder, a tool designed for the Elecraft K4 radio by hams. The tool collects S-Meter readings and saves them to a CSV file, allowing users to create graphs of RFI over time. These graphs are valuable during RFI hunting, aiding in pinpointing the source. Visitors can view the program's interface, download it at their own risk, and subscribe to the blog for updates. The page provides insights into the K4 S-Meter Recorder's functionality and usage for ham radio operators seeking to manage RFI effectively.

The page provides details on an improved filter for the TS440 CF2 slot with better selectivity and shape factor than stock versions. It includes information on LTSpice Analysis, essential changes to capacitors, and suggestions for optimizing audio bandwidth for AM phone use. The content is geared towards hams or amateur radio operators looking to enhance their TS440 transceiver performance with filter upgrades and capacitor adjustments.

The York County Amateur Radio Club (YCARC) in Maine, USA, promotes amateur radio knowledge and camaraderie. The site features club information, activities, and upcoming events for radio enthusiasts.