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Explore the process of creating a custom adapter for the Yaesu FT-8900 radio with a non-standard mic port. The article guides users through understanding the reversed pin-out of the RJ-12 connector on the 8900, providing a detailed circuit for adapting the voltage for electret-based mics. With a list of required parts and construction tips, this DIY project ensures seamless compatibility with standard electric headset mics.

Chavdar Levkov, LZ1AQ, presents an experimental comparison of small wideband magnetic loops, building on his previous work on wideband active small magnetic loop antennas. His research focuses on increasing loop sensitivity by maximizing the short-circuit current, which is directly tied to the "loop factor" M = A/L, where A is the equivalent loop area and L is its inductance. Levkov's methodology involves reducing inductance and increasing area through parallel or coplanar crossed (CC) configurations, comparing these designs against a reference single quad loop of 1 m2 area. Experimental verification included testing three distinct loop types: a simple quad loop, two coplanar crossed (CC) loops, and eight parallel loops, all designed to have a total geometric area of 1 m2. Measurements were conducted at 1.8, 3.5, 7, and 10 MHz using a small transmitter 270 meters away, with a Perseus direct sampling receiver for precise signal level assessment. The results consistently showed that CC loops, particularly Loop 5 (two CC circular loops with 1.44 m2 total area), yielded significantly higher currents, up to 9.1 dB over the reference loop at 3.5 MHz, validating M as a reliable predictor of loop sensitivity. Numerical simulations using MMANA further corroborated the experimental findings, demonstrating an almost perfect correlation between the calculated M factor and the induced loop current for 15 different loop models. Levkov concludes that CC loops offer superior sensitivity for a given loop area, while parallel loops are advantageous for minimizing physical volume. Practical recommendations suggest using loops with an M factor greater than 0.5 uA/pT for quiet rural environments, and he provides a spreadsheet tool, WLoop_calc.xls, to aid in optimizing loop configurations for specific operational needs.

This PDF file provides detailed information on HF propagation for ham radio operators. It covers the principles of how radio signals travel over long distances, including factors that affect signal strength and propagation. The content is useful for hams looking to improve their understanding of radio communication and optimize their transmissions. Whether you're a beginner or an experienced operator, this resource offers valuable insights into HF propagation that can enhance your communication skills and efficiency on the airwaves.

Twigger is a very lightweight, free ham radio logger designed for Windows, offering seamless integration with transceivers via _TCI_ or OmniRig. This software stores all logged contacts in a SQLite database, with the flexibility to export daily ADIF files for import into a main logger or to send real-time QSO data via UDP in N1MM XML format. It also supports direct, real-time uploads to popular online logbooks like Clublog and QRZ.com, streamlining the logging process for active operators. The application has seen continuous development, with version 1.1.34 fixing an ADIF log importer bug and earlier versions adding crucial features like WSJT-X/JTDX UDP support. Author OE3IDE, Ernst, has incorporated user feedback, including ideas and testing from MW0LGE, to refine the software. Key enhancements include the transition to SQLite for data storage in version 1.1.32, allowing for easy import of previous Twigger ADIFs upon initial startup. The logger also features integrated DX cluster support, enabling users to send spots directly and query QRZ.com for callsign information, which is then cached to reduce redundant queries. The software's compact design and essential logging capabilities make it a practical tool for casual logging or as a secondary logger during contests, with the ability to handle **25 downloads** for version 1.1.34.

SAT_EXPLORER is a versatile software for tracking the Moon, Sun, and artificial satellites while controlling various antenna interfaces. Compatible with Windows XP and later (32/64-bit) and multilingual (English, French, German, Italian, Spanish), it integrates seamlessly with TRX-Manager for transceiver control. SAT_EXPLORER computes satellite and Moon positions with high precision, calculates EME Doppler shifts, and uploads real-time satellite positions and coverage maps to your personal web pages. Linux/Ubuntu users can run it using WINE or CROSSOVER.

This **PDF report** documents a _maritime mobile_ DXpedition operating from the _Southern Ocean_ near Antarctica, detailing antenna deployment strategies on a sailing vessel. It addresses power management systems for remote operations and propagation characteristics specific to polar regions on **20m and 40m** bands. Operational strategies include managing high-density pileups using split frequency operation and maintaining signal integrity during periods of high aurora activity. Equipment considerations cover specific transceiver models like the Icom IC-7300, antenna types optimized for marine vessel installation, and battery power systems for extended periods without shore power. The resource also examines the use of satellite communication for real-time log uploads and QSL confirmation from remote locations, and discusses mitigating signal degradation from ice accumulation on antennas. DXZone Focus: PDF report | Maritime Mobile DXpedition | Polar Propagation | Split Frequency Operation

This PDF document contains construction notes for a Yagi antenna designed for the 146 Mhz frequency range. It provides detailed instructions and information on how to build the antenna, making it a valuable resource for hams looking to improve their radio setup. The document covers the materials needed, step-by-step construction process, and tips for optimizing performance. Whether you are a beginner or an experienced ham radio operator, these construction notes can help you enhance your antenna system for better communication.

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.

Morse News reads RSS/Atom messages and translates them into Morse code, playable as CW radio tones, spark-gap sounds, telegraph clicks, or via a physical telegraph sounder. It supports Farnsworth effects, natural American Morse timing, and realistic audio enhancements. Twitter integration allows user-generated Morse messages.

This PDF document discusses the setup and operation of UHF vertical dipole phased stack antennas for hams. It covers the advantages, principles, and practical aspects of using this type of antenna configuration. The document is a useful resource for amateur radio operators looking to improve their UHF station setup with phased array antennas.

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.

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.

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.

The article details the repair of an Elecraft K3 transceiver experiencing an "ERR 12V" issue, causing reduced output power. The problem, common in these units, stems from inadequate pin strips carrying high DC current to the PA unit, leading to overheating and poor conduction. The author identified the faulty connectors and implemented a bypass using existing PCB pads, effectively rerouting the power and resolving the error. This straightforward fix highlights the importance of robust electrical connections in high-current applications, restoring the K3's full functionality.

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

Demonstrates various technical projects and tutorials for amateur radio operators, focusing on digital modes, monitoring, and station setup. It covers topics such as implementing a _WSPR_ station, setting up ADS-B reception, configuring a _DXSpider_ cluster, and utilizing monitoring tools like Prometheus and Grafana. The resource provides practical guides for integrating modern IT solutions with ham radio activities, including Docker and Linux environments for radio applications. This site also features a publicly accessible online logbook, offering detailed statistics on QSOs by band, mode, and geographical zone, with visual mapping of contacts. It includes a comprehensive amateur radio lexicon, explaining hundreds of terms, and provides a real-time display of the F4HXN station's local weather conditions. The resource also aggregates information on upcoming ham radio events and offers a **SWR simulator** for antenna analysis, allowing users to visualize ROS changes based on frequency and antenna parameters.

For sale used unwanted HAM and CB Radios for sale in your area. Post your unwanted radio items to others for free.

Presents the S21WD DXpedition to Bangladesh (IOTA **AS-140**) scheduled for 2026, organized by the Next Generation DX Club e.V. It outlines the project's progress, including final hardware and systems testing, and the team's successful arrival and activation from the target location. The resource provides a concise summary of Bangladesh, covering its geography, cultural aspects, and economic landscape. The page includes the Clublog Most Wanted ranking for Bangladesh, categorized by continent and mode, as of January 2026. The DXpedition aims to achieve over 70,000 QSOs across CW, SSB, RTTY, and FT8 modes, with a specific focus on RTTY (targeting over 2,000 QSOs) and **lowband** operations. The team plans a Multi-Single entry in the ARRL CW 2026 contest. QSO data will be uploaded to Clublog and LoTW, with Clublog livestream and daily free LoTW uploads anticipated, contingent on stable internet connectivity. The S21WD callsign corresponds to CQ Zone 22 and ITU Zone 41. Further details include a preliminary bandplan, FT8 operating guidelines using MSHV software, a VOACAP DX Prediction link, and an azimuthal map centered on Bangladesh. QSL services are managed by DJ4MX via Clublog OQRS, offering direct, bureau, and LoTW options, with daily LoTW uploads expected.

The **CubeSat** standard, developed by California Polytechnic State University (Cal Poly) and Stanford University, facilitates frequent and affordable access to space for small satellites. This resource serves as a central hub for the CubeSat community, offering a comprehensive directory of active and past CubeSat projects, technical specifications, and educational materials. It details the standardized dimensions and mass constraints for these pico-satellites, which typically range from 1U (10x10x10 cm, 1.33 kg) to 12U configurations, enabling their deployment as secondary payloads on various launch vehicles. The site also provides insights into mission planning, component selection, and regulatory considerations for amateur radio satellite operations. Operators and developers can utilize the project directory to research existing CubeSat missions, understand their communication protocols, and identify potential collaboration opportunities. The platform's forum section allows for direct engagement with other enthusiasts and experts, fostering knowledge exchange on topics such as **AMSAT** frequency coordination, telemetry decoding, and ground station setup. This collaborative environment supports the development of new CubeSat projects, promoting innovation in amateur radio satellite communication and space exploration.

This page by Andrew Woodfield ZL2PD provides information on CMOS HF Digital Dial for hams. It covers design options, circuit description, construction, alignment, and operation. The page also includes references and downloads. Whether you're looking to build or understand a digital dial for your HF rig, this page offers valuable insights and resources.

Details the Virtual COM Port (VCP) drivers for Silicon Labs CP210x USB to UART Bridge devices, which are crucial for establishing serial communication between a host system and CP210x-based hardware. It covers driver availability for Windows, macOS, Linux, and Android, highlighting the necessity of these drivers for operating CP210x products as a virtual COM port. The resource also mentions the option for direct access drivers and references _Application Note 197_ for comprehensive serial communication guidance. The page specifies that the CP210x Manufacturing DLL and Runtime DLL have been updated, requiring their use with v6.0 and later of the Windows VCP Driver, impacting specific application note software downloads like AN144SW.zip. It notes that Linux 3.x.x and 4.x.x driver versions are maintained within the _Linux kernel tree_ at www.kernel.org, ensuring ongoing support. Legacy OS software is also provided for users requiring support for 5.x drivers, ensuring broad compatibility.