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- Radio Equipment > HF Amplifiers > Acom 1000
- Radio Equipment > HF Amplifiers > Acom 1010
- Technical Reference > Components > Component Database
- Shopping and Services > Electronic Components
- Manufacturers > Electronic Components
- Manufacturers > Transceivers > Icom
- Radio Equipment > Antenna Tuners > Icom AH-4
- Radio Equipment > VHF-UHF Mobile > ICOM IC-2100H
- Radio Equipment > VHF-UHF Mobile > Icom IC-2300H
- Radio Equipment > VHF-UHF Mobile > ICOM IC-2720H
- Radio Equipment > HF Transceivers > Icom IC-7000
- Radio Equipment > HF Transceivers > Icom IC-703
- Radio Equipment > HF Transceivers > Icom IC-705
- Radio Equipment > HF Transceivers > Icom IC-706
- Radio Equipment > HF Transceivers > Icom IC-7100
- Radio Equipment > HF Transceivers > Icom IC-718
- Radio Equipment > HF Transceivers > Icom IC-7300
- Radio Equipment > HF Transceivers > Icom IC-746
- Radio Equipment > HF Transceivers > ICOM IC-756
- Radio Equipment > HF Transceivers > Icom IC-7600
- Radio Equipment > HF Transceivers > Icom IC-7700
- Radio Equipment > HF Transceivers > Icom IC-7760
- Radio Equipment > HF Transceivers > Icom IC-7851
- Radio Equipment > HF Transceivers > Icom IC-9100
- Radio Equipment > Receivers > Icom IC-R20
- Radio Equipment > Receivers > Icom IC-R7100
- Radio Equipment > Receivers > Icom IC-R75
- Radio Equipment > VHF-UHF Mobile > Icom IC-V8000
- Radio Equipment > VHF-UHF Handhelds > Icom ID-51A
- Radio Equipment > VHF-UHF Mobile > ICOM ID-880H
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This page provides information on how amateur radio, or 'Ham' radio, is used by the yachting and small boat community for communication and weather information. It explains the global operation of amateur radio, regulations within the U.S., and the role of the American Radio Relay League (ARRL) in licensing and training. The page also highlights maritime 'nets' where Hams exchange weather reports, using voice and digital modes. It encourages establishing webpages for nets and mentions the MAROB and SKYWARN Programs for marine observation and severe weather reporting. The content is useful for hams interested in maritime communications and weather reporting.
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Ham2K PoLo is an android Portable Logger, Support for Parks On The Air (POTA), Summits On The Air (SOTA), Field Day, Winter Field Day, Worldwide Flora and Fauna (WWFF) and more. Fast and efficient yet fully-featured: QRZ.com name lookups, QSO Maps, offline data files, contact rates, duplicate warnings, POTA spots, search parks nearby or by name, etc.
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March 1-11 2023 DXPedition to Galapagos, Santa Cruz Island SA-004
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This article describes the implementation and testing of a low-power GPS tracker using LoRa technology in the 433MHz amateur band. The system, built with AIThinker RA-02 modules and Arduino controllers, demonstrated successful communication over non-line-of-sight distances up to 5km. Operating with a 125kHz bandwidth and spreading factor of 11, the tracker achieves a data rate of 500 bits/sec. Powered by a LiPo cell with power-saving features, the final compact design operates for approximately 1.5 weeks between charges with 3-minute reporting intervals, consuming just over 1mA in idle mode.
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This article About Noise offers a clear, non-mathematical explanation of noise in telecommunications, making it accessible to radio amateurs. It categorizes noise into fundamental and intermodulation types, detailing sources like thermal, shot, and cosmic noise. The article effectively highlights noise impact on receivers and introduces key metrics like Noise Figure and Signal-to-Noise Ratio (SNR). While comprehensive, it remains digestible, balancing technical depth with simplicity. A great resource for understanding radio noise fundamentals without complex equations, though a more detailed discussion on mitigation techniques would further enhance its value.
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VicScan is a Radio Scanning web forum about Victoria Australia
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An owner point of view of the Yaesu FT-818 QRP transceiver capable to work HF VHF UHF in CW, AM, LSB, USB, FM, PACKET.
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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.
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The ZL1WTT resource details an experimental software-based Digital Amateur Television (DATV) system, demonstrating the multiplexing of up to six standard-definition (SD) and one high-definition (HD) channel utilizing _h264 compression_. The author encountered peak data rates reaching 32 Mbit/s, necessitating a shift to Freeview and Sky settings (22.5M Sym/s 3/4FEC) to manage bandwidth. The setup employs four networked computers, with a laptop functioning as the multiplexer to re-code PIDs for various inputs, including looped MPEG2 playlists, MPEG2 encoder card input from a VCR, satellite feeds, and an off-air UHF receiver. The system highlights the inherent flexibility of the DVB transport stream, supporting diverse formats such as MPG2, h264, AC3, and AAC. A significant advantage of this software-defined approach is the absence of video quality degradation from stored MPEG2 files to the displayed output, coupled with the ease of reconfiguring settings for MPEG2 encoder cards (e.g., size, bit-rate, frame rate, video input, coding format) and satellite receiver cards (e.g., frequency, LNB volts, symbol rate, FEC). The author also discusses the development of a new graphical user interface (GUI) using _Gambas_ for Linux, aiming to simplify configuration for this DATV project. Specific hardware components mentioned include Hauppauge WinTV PVR-150 and Nova-S plus cards, with a focus on optimizing analog video input via Y/C (S-video) to minimize frequency roll-off. The resource also provides insights into data rates for HD (1080i) content, recommending 8 to 12 Mb/s for optimal performance. Software utilized includes _Ubuntu Studio 10.04_, WinFF, VLC, and TMPGEnc Editor, underscoring the project's reliance on open-source tools and a foundational understanding of LAN networks and DVB transport streams.
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The **5-Port 12 Volt DC Power Strip Kit (Rev 4)** offers a practical solution for managing shack power distribution, providing one input and five fused outputs. All connections utilize the ubiquitous Anderson PowerPole connectors, a standard for many amateur radio operators, ensuring a clean, organized, and safe way to power multiple 12 VDC transceivers and accessories from a single source. This design mitigates the common issue of tangled wires and overloaded connections in a typical ham shack. Rated for a maximum current of 20 Amps at 12 VDC, the strip incorporates an integrated LED to indicate when external power is applied. Each output is individually fused, a critical safety feature that protects connected equipment from overcurrent conditions without affecting other devices on the strip. This level of protection is essential for preserving sensitive radio gear during operation. Assembly requires basic soldering skills and hand tools, with a high-power soldering iron and wide chisel tip specifically recommended for best results. The kit's compact dimensions of 4.13" x 1.78" allow for flexible mounting via screw holes, making it suitable for various shack configurations and portable operations.
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AA9PW offers free practice exams for all three US license classes plus international licenses like Canadian and Australian. The site generates random tests from the current question pools, simulating the actual exam experience. You can choose between online exams or printable PDF versions for offline study. The site maintains a simple, no-frills interface that loads quickly even on slow connections. Practice tests provide immediate feedback with score reports highlighting areas needing improvement.
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E51D North Cook Islands DX Pedition, Penrhyn Atoll (Tongreva) Aug 22 - Sep 9 2023
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Examines the historical context of amateur radio, specifically focusing on Guglielmo Marconi's pioneering wireless transatlantic signal reception at Signal Hill, Newfoundland, in 1901. It describes the operation of a contemporary remote radio station at Signal Hill, utilizing the special event call sign _VD1M_ issued by Innovation, Science and Economic Development Canada. The content recounts a specific contact from Signal Hill, reporting a signal strength of 5 by 9 to a station in Sarnia, Ontario, which received the signal at 3 by 3. The narrative also introduces the concept of 'Marconi chasers' who endeavor to replicate historical transmission methods. Further, the resource discusses general amateur radio operating procedures, the evolution of the hobby, and its critical role in emergency communications, citing examples from hurricanes _Irma_ and _Maria_ in 2017 and the conflict in Ukraine in 2022.
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This document provides a comprehensive guide on renewing an US amateur radio license through the Federal Communications Commission (FCC) using the new COmmission REgistration System (CORES). Published on QST October 23, it outlines the necessary steps for creating a CORES account, associating it with a Federal Registration Number (FRN), and completing the renewal application. Key points include the requirement of a $35 fee for the renewal process, which must be paid online after the application is submitted. The guide emphasizes the importance of logging into the FCC License Manager system during the renewal window and provides instructions on how to navigate the renewal process, including obtaining confirmation and access to the renewed license. Additionally, it offers contact information for FCC support and links to further resources for assistance.
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An Arduino-based interface provides a remote tuner call command for Icom **IC7700** and **IC7800** transceivers, addressing the lack of a built-in function for external tuners such as the MFJ 998RT. This setup initiates a low-power transmit signal, typically 15 watts, allowing the remote autotuner to perform its matching sequence. The article details the required CI-V line communication and modifications to existing Arduino code, specifically referencing contributions from Jean-Jacques ON7EQ for improved Icom interrogation routines. The system involves a sequence of steps: storing the transceiver's current mode and power, disabling the internal autotuner, activating a control relay to interrupt the amplifier line, switching to RTTY mode at low power, and initiating transmit. The transmit duration is manually controlled by the operator, observing the SWR meter until a low SWR is achieved, then a second button press stops the transmission. A built-in 4-second transmit limit provides a safety measure. After tuning, the routine restores the original mode and power settings, re-enables the internal autotuner, and performs a brief 2-second RTTY transmission for internal tuner adjustment. The circuit diagram includes a Panasonic form 2 relay for amp control and emphasizes critical delays in the Arduino code for stable operation at 9600 baud CI-V communication. Compatibility with logging software like DXLab, N1MM, and N3FJP is noted, with specific interrogation time settings required to avoid conflicts.
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Documents the operational planning for the **XX9W** DXpedition to Macao, a **DXCC** entity. This resource outlines the team composition, identifying 14 operators from various IARU regions, including EA1CJ, F2JD, and JH4RHF. It details the expedition's objective to activate Macao, officially the Macao Special Administrative Region of the People's Republic of China, emphasizing its distinct blend of Portuguese and Chinese cultures, historic architecture, and urban landscape. The site also provides information on how to support the DXpedition through donations, facilitating contributions via PayPal. Macao operates under the "one country, two systems" principle, with Chinese (Cantonese) and Portuguese as official languages, and a population exceeding 680,000. The content highlights the region's geographical location on the southern coast of China, across the Pearl River Delta from Hong Kong, and its historical background as a Portuguese colony.
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Allstar Linked Repeaters On The Air (ALROTA) is a community-focused platform aimed at strengthening connections within the amateur radio world. It offers a range of features, such as personalized connection schedules, net discovery tools, and a dedicated Radio Check Hub, all designed to improve the radio experience. Additionally, ALROTA supports emergency communication services and provides training opportunities for amateur radio
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Presents an online retail platform for amateur radio operators, showcasing a diverse inventory of equipment and accessories. The site lists popular transceivers such as the _Icom IC-7300_ and _Icom IC-7610_, alongside various antenna solutions including base, HT, mobile, and end-fed designs. Operators can find coaxial cable, including bulk options and products from "The Wire Man," essential for shack setup. The platform also stocks crimping and stripping tools, adapters, and power supplies, crucial for station maintenance and construction. Test equipment like _RigExpert Analyzers_ and accessories such as Daiwa meters and _West Mountain Radio_ Power Poles are available. Additionally, the site offers software from _Ham Radio Deluxe_ and _RT Systems_, catering to logging and radio programming needs. Shipping policies include free shipping on C.Crane Radios and most orders over $100.00 within the lower 48 states, providing clear purchasing incentives.
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Join Kirk Pickering, K4RO, as he delves into the importance of calling CQ in amateur radio contesting. Learn about the debate over spotting assistance and why developing tuning and identifying skills is crucial for contest operators, especially newcomers. Discover valuable insights on how to enhance your contesting experience and maximize your success.
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The St Paul Island CY9C DXpedition is scheduled for August 26, September 5, 2024. All bands from 160-6 meters are planned.
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This article discusses a high performance, 7MHz, 5 watt SSB rig, the Daylight Radio, an all-analog radio design from the 1980s that includes a full circuit diagram, IMD NR60 calculations, QER crystal filter, bandpass filter, receiver portion, and more. The author explores the design, components, and functionality of this analog radio for hams interested in vintage or homebrew radio projects.
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Learn how to modify your Baofeng 888s radio to use in an Allstar node. This article provides step-by-step instructions on programming the radio with suitable frequencies for amateur radio use, including tips on using the Chirp program. Make sure to use a cable with a Genuine FTDI Chipset for easy connection to your computer. Avoid transmitting on pre-programmed channels to prevent trouble. Follow the guidelines provided to customize your radio settings and ensure a smooth modification process. Visit the link for Chirp program download and consult Miklor for programming assistance.
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Learn how to leverage AI assistants like ChatGPT for designing circuits. Electronics engineers can benefit from using ChatGPT for hardware design projects, especially when facing challenges in the analog domain. Discover how AI can enhance productivity and provide solutions to complex hardware design questions. Explore the future of electronics design with ChatGPT and similar chat assistants.
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A homemade oak plank drive-on mast holder proved functional but heavy and cumbersome. A lighter, compact commercial version from Amazon seemed ideal but couldn't fit the preferred Jackite pole. Costly alternatives, like a $100 mast holder from Three Mosquitoes Gear, were impractical. The solution came through DIY ingenuity: a piece of 2" PVC and hose clamps, repurposing materials already on hand. This simple, effective design perfectly accommodated the Jackite pole, demonstrating the power of resourceful problem-solving.
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After years of reliable performance, a 26-year-old Icom 706MK2G exhibited an unusual deviation during FM transmission, with the actual frequency being 10kHz off from the displayed frequency. Additionally, the power meter showed a sharp dip during transmission. Upon investigation, it was discovered that the FM VCO voltage adjust variable had become dirty and sluggish over time. By adjusting the variable capacitor and cleaning it with switch cleaner, the issue was resolved, restoring stable power output and accurate frequency transmission.
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This page by Arctic Peak provides a detailed explanation on how to use quarter-wave transmission lines as impedance transformers in ham radio antenna work. It explains how to match impedance values by connecting them with a λ/4 transmission line. The page also offers guidance on constructing your own transmission lines with specific impedance requirements, along with a calculator to determine the quarter wave length based on velocity factor and frequency. Useful for hams looking to optimize antenna performance and match transmission line impedance effectively.
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This resource presents a non-rigorous evaluation of the front-to-back (F/B) ratio of short Beverage antennas, specifically designed for low-band operation on frequencies such as 160, 80, 40, and 30 meters. The author, VE1ZAC, details the methodology used to measure the F/B ratio, which involves using a Millen Grid Dip Oscillator as a portable signal source. Measurements were taken by switching the antenna direction and recording S Meter and preamp readings to derive gain numbers. The document discusses the challenges faced in achieving accurate measurements and the assumptions made during the process, such as the calibration of S Meter units at 6 dB. This evaluation is particularly relevant for amateur radio operators interested in antenna performance on low bands.
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The page features a spreadsheet that calculates power in watt and dBm based on voltage and impedance, power in dBm with a given power and impedance, voltage in millivolts with a given power and impedance, and more. It also converts between millivolt, microvolt, volt, watt, and milliwatt. Useful for hams looking to accurately calculate power and voltage values for radio equipment. Last updated in December 2014.
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Presents a four-part video series documenting the assembly of the Elecraft KX3 QRP transceiver, offering insights into the construction process. The author, VE9KK, shares practical tips and addresses challenges encountered during his own build, providing guidance to help other builders achieve a smoother experience. The videos, while not a step-by-step instructional guide, showcase completed assembly stages and discuss lessons learned. This approach allows builders to anticipate potential pitfalls and apply proven solutions, drawing from the author's direct experience with the _KX3_ kit. Specific attention is given to areas where builders often face difficulties, ensuring that critical details are covered to facilitate successful completion of the transceiver, which is renowned for its **10-watt** output and versatile operating modes.
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_Icom_, _Yaesu_, and _MFJ_ are among the renowned brands available at R&L Electronics, a dedicated store for amateur radio enthusiasts. The store provides a diverse selection of equipment, catering to both novice and seasoned operators. From amplifiers and preamps to antennas and tuners, the store ensures a comprehensive inventory to meet various operational needs. Customers can also find essential components like cables, coax, and connectors, crucial for setting up and maintaining effective radio stations. In addition to new equipment, R&L Electronics offers used items, providing budget-friendly options without compromising on quality. The store's inventory includes test equipment and tools, vital for troubleshooting and optimizing radio performance. Tower components are also available, supporting those involved in more advanced setups. The website facilitates easy access to product information, shipping details, and order tracking, enhancing the shopping experience. R&L Electronics stands out by offering a variety of products that cater to different preferences and budgets, ensuring that every amateur radio operator can find the necessary equipment to enhance their setup.
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A high-technology enterprise specializing in the R&D, production and sale of two-way radio equipment for over twenty years. DMR Radio, Digital and analog portable radio manufacturer based in China
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Radio club mainain in the city of Rivne the Repeater 145 MHz Tx 145.637.5 MHz . Rx 145.037.5 MHz
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Unicom Radio, since 2005, has excelled in the communications and telecommunications market, offering advanced services across diverse industries globally. Specializing in corporate communication systems, base station construction, and professional antenna systems, Unicom Radio leverages expertise to deliver high-tech equipment internationally. Unified by a strategic vision, the company continues to innovate and build trust with partners and clients.
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Learn how to enhance your Drake R-4B ham radio receiver by adding a panadapter. Follow along as the author shares their journey of becoming a ham radio operator and restoring vintage radios. Discover how a panadapter can help you visualize a wider frequency range, improving signal detection and communication. Whether you're a seasoned ham or just starting out, this guide provides valuable insights and practical tips for maximizing your radio experience.
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Over 200 distinct 2-meter band amateur radio repeaters are cataloged for Australia, providing essential operational data for VHF communication. Each entry specifies the repeater's output frequency, often including the input tone (e.g., **91.5 Hz** or **123.0 Hz** CTCSS) and the repeater's callsign (e.g., _VK2RSC_, _VK3RHF_). Locations are precisely noted, frequently referencing specific towns, mountains, or geographical features such as "Kinglake, Kangaroo Ground" or "Adaminaby, Mars Hill." The resource also indicates various digital modes and linking capabilities where applicable, such as "FMEchoLinkFusionWIRES-X" or "DMR," alongside standard FM operation. This detailed listing facilitates local and regional VHF communication, enabling hams to program their transceivers accurately for repeater access. The data is presented in a clear, tabular format, making it straightforward to identify repeaters by frequency and location.
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This article describes a DIY RF field strength meter project inspired by VK3YE's "The Squeakie" design. The device, built around a 555 timer IC and a 1N4148 diode, converts RF signal strength into audible tones with proportional pitch. The author enhanced the original design by adding volume control, LED indication, and digital readout capabilities using an Arduino Nano and LCD display. The completed project functions as a versatile RF detection tool, suitable for antenna testing and fox hunting, while offering multiple output methods: audio, visual, and digital measurement display.
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This page explores the World Wide Flora and Fauna (WWFF) and Parks on the Air (POTA) programs, highlighting their shared goals, distinctive features, and how they complement each other. It is designed for park enthusiasts who enjoy participating in both programs, offering insights, tips, and resources to maximize enjoyment and success in portable operations from natural areas. Whether you're new to park activations or a seasoned operator, this guide celebrates the opportunities offered by both WWFF and POTA, fostering appreciation for all aspects of amateur radio in nature.
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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.
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This article explores the historical importance of clandestine radio stations in Algeria's fight for independence. It discusses the power of radio as a tool for communication and public opinion shaping. The content delves into the impact of underground radio stations in times of crisis and their role in achieving power, revolution, independence, or democracy. The article reflects on the evolution of radio in Algeria throughout the 20th century and its adaptation to societal changes. It provides insights into the significant events witnessed by Algerian radio and the influence of clandestine broadcasting in the country's history.
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PortFlux provides a software-defined virtual serial cable solution for Windows operating systems, specifically supporting x64 and ARM64 architectures. It facilitates the creation of paired virtual COM ports, allowing two distinct applications to communicate as if connected by a physical null-modem cable. The utility is designed to bridge data streams between software requiring serial port access, such as logging programs, rig control applications, or digital mode clients, without the need for physical hardware interfaces. This software addresses the common challenge of connecting multiple ham radio applications that each demand exclusive access to a single physical serial port. By establishing virtual pairs, PortFlux enables simultaneous operation of, for instance, a contest logger and a digital mode program, both interacting with a single transceiver via a shared virtual link. The GitHub repository includes source code, offering transparency and the potential for community contributions or custom modifications.
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This page provides an introduction to the ZL2PD LED Frequency Counter. It covers the design, construction notes, and downloads related to the project. Created by Andrew Woodfield, ZL2PD, this resource offers valuable information for hams interested in building their own frequency counter using LEDs. The content is dated June 12, 2010, with a revised version 2.0. The page also credits the template design by Andreas Viklund.
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Manufacturers of roof towers ideal solution for HOA restrictions, Limited lot space, 2nd or 3rd tower and perfect for satellite & ISS
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Temotu 2024 DXpedition February 22nd, 2024 - March 7th 2024.
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INTERCOM is a freeware application designed for remote control of KENWOOD TMD700/710/V-71 transceivers, as well as other transceivers equipped with UP, DOWN, and PTT commands. Compatible with Windows XP and higher (32 & 64-bit), INTERCOM offers multilingual support in English and French, and can be used on Linux, Ubuntu, or Android platforms via WINE 1.0 or CROSSOVER. The software enables users to send basic commands—such as selecting TX, VFO, memory channels, or power levels—either through manual inputs or over a TCP/IP link. INTERCOM is tailored for SIMPLEX setups, facilitating the interconnection of VHF/UHF repeaters with nearby repeaters. Remote commands are transmitted using DTMF codes, which are decoded by SIMPLEX and forwarded to INTERCOM via TCP/IP. This functionality makes INTERCOM an ideal tool for radio enthusiasts and operators seeking seamless remote management of supported transceivers in simplex configurations.
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QRZ Label is a Windows application designed for amateur radio operators to generate QSL labels using _Zebra (ZPL)_ label printers. It interfaces directly with QRZ.com to retrieve callsign and address details, and can import QSO log data from the QRZ Logbook. The software then formats this information into various label types, including standard address labels, envelope labels, greeting labels, and multi-QSO confirmation cards, all featuring an on-screen tabbed preview. The application supports the creation of QR-code labels, specifically a "QRZ Link" type, which can streamline the QSL process by providing a scannable link to the contact's QRZ.com page. This functionality enhances the traditional QSL card exchange with modern digital convenience. Developed by K7CTV, QRZ Label offers a practical utility for hams managing their QSLing workflow, providing a **free** solution for printing professional-looking labels directly from their station data. The software is distributed as a signed Windows installer.
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The article details how to eliminate Radio Frequency Interference (RFI) from the Behringer HA400 headphone amplifier when used in ham radio setups. While the HA400 is praised for its quality and affordability, it was not designed for RF environments, causing distortion when used with a 500-watt radio station. Initial attempts using clamp-on ferrites on the headphone and power cables only partially resolved the issue. Upon opening the unit, the author discovered the circuit lacked RF bypassing components. The solution involved installing 0.1μF (104) capacitors at key points in the circuit: the power supply input, audio circuits, and op amp inputs. This modification, combined with the external ferrites, completely eliminated the RFI problem, making the unit suitable for ham radio operations.
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DX Pedition to Conway Reef by Rebel DX Group. A 2 men activity from Conway Reef from 6m to 160m
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Fox Hunting for Scouts. Jamboree can be an opportunity to promote ARDF among Scouts all around the world.
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Learn about noise blankers in the FT-817 transceiver, why they may not work, and how to repair them. Follow the repair guide provided to improve your radio's performance, especially for activities like Meteor Scatter. Written by EA4EOZ, an amateur radio electronic enthusiast, this page offers valuable insights for hams looking to enhance their equipment.
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This online project documentation details the construction of a hands-free microphone interface unit designed for _mobile_ amateur radio operation. The curriculum covers the integration of electret microphone elements with amateur radio transceivers, specifically addressing **VHF** band communication. It outlines the circuitry for a switch box that provides an interface between various radio models and microphone types. The guide specifies the inclusion of a **1750 Hz** tone-burst generator for accessing amateur radio repeaters, an operational protocol for many VHF systems. Design considerations include the reduction of ambient vehicle noise through an adjustable audio input level control. The project provides schematics and wiring diagrams for connecting the interface unit to specific amateur radio transceivers, including the Yaesu FT-817. It addresses the selection and adaptation of readily available electret microphone and earpiece assemblies, initially sourced from mobile phone accessories, and later from dedicated headset units. The design incorporates a control mechanism for radio functions, enabling hands-free operation during _mobile_ excursions. Circuit details cover power supply considerations for the electret microphone and signal routing for both transmit audio and received audio monitoring. The documentation specifies component selection for the switch box, ensuring compatibility with common amateur radio microphone input impedances and output levels. This includes considerations for PTT line switching and audio path isolation. DXZone Focus: Online Project Documentation | Hands-Free Mobile Microphone Interface | Electret Microphone Integration | 1750 Hz Tone-Burst Generation