Search results

A freeware windows morse code trainer for beginners and experts by DK5CI

Vox Recorder is a specialized Windows utility designed for amateur radio operators, and radio listeners particularly those who use radio scanners. This software allows users to record audio from various sources, but it only activates when an audio signal is detected. This feature is particularly useful for avoiding the capture of silence or background noise, which can be common in radio scanning. By focusing on the audio signals, users can create cleaner recordings that are more relevant to their interests. The utility is user-friendly and tailored for hobbyists who want to document their radio listening experiences without the hassle of editing out silence later. Vox Recorder is an excellent tool for anyone involved in amateur radio, as it streamlines the recording process and enhances the overall experience of monitoring radio frequencies. Whether for personal use or for sharing with fellow enthusiasts, Vox Recorder helps ensure that every important transmission is captured effectively.

Presents the official download hub for the _Fldigi_ suite of amateur radio software, detailing its core components and associated utilities. The resource provides direct access to executables and source code for Linux, FreeBSD, macOS, and Windows operating systems, alongside comprehensive documentation in PDF format for each application. Specific version numbers and release dates are listed for _Fldigi_, _Flrig_, _Flmsg_, _Fllog_, _Flnet_, _Flaa_, and other tools, indicating active development and maintenance. It outlines the distinct functions of each program, such as _Fldigi_ for digital modem operations, _Flrig_ for transceiver control, and _Flmsg_ for NBEMS messaging. The site also references support communities on groups.io for Linux, NBEMS, and Windows users, fostering a collaborative environment for troubleshooting and usage guidance. Furthermore, it links to third-party repositories and mirrors, including SourceForge, for alternative download options and distribution-specific packages like RPMs for OpenSUSE and COPR for Fedora. The resource also includes links to _RigCat_ XML files for transceiver control configurations and a dedicated Wiki for _Fldigi_, offering additional technical insights and build instructions. This centralized repository serves as the primary distribution point for the W1HKJ software ecosystem, ensuring users can access current versions and support materials.

Presents a practical design for a **crossed-dipole turnstile antenna** specifically engineered for 2-meter Amateur Radio Direction Finding (ARDF) events. The author, WB6RDV, details a robust, omnidirectional, horizontally-polarized antenna, addressing the international ARDF rules requiring such characteristics at a height of two to three meters above ground. This contrasts with the vertical polarization often used in Southern California, highlighting the design's adherence to specific event requirements. The electrical design employs a classic crossed-dipole with a 75-ohm phasing section, resulting in a slight impedance mismatch and an SWR of approximately 1.3:1 with a 50-ohm feedline. Construction utilizes readily available and inexpensive PVC plumbing components and 1/8-inch bronze welding rod for elements. The guide provides step-by-step instructions for mechanical assembly, including drilling element holes at precise 90-degree spacing and preparing the RG-179 matching section. WB6RDV shares insights from his own build experience, discussing the use of plated brass versus aluminum spacers for element attachment and the effectiveness of crimping as an alternative to soldering. The document also covers final assembly, including the integration of ferrite beads as a choke balun and options for weatherproofing and alternative mounting configurations, emphasizing the adaptability of the design for other VHF bands through scaling.

Orbitron, a cardware application, provides robust satellite tracking capabilities for radio amateurs and visual observers alike. It leverages NORAD SGP4/SDP4 prediction models to accurately display satellite positions in real-time or simulation, accommodating up to 20,000 objects loaded from _TLE files_. The software includes an advanced search engine for satellite passes and _Iridium flares_, offering printable results for planning observations or QSO attempts. Sebastian Stoff's creation supports various visualization options, including a 'Nightlife' dark color scheme for nocturnal use, and integrates a database of cities and satellite frequencies. Users can synchronize their PC clock via NTP and update TLE data over HTTP, with ZIP support. The application also features rotor and radio control capabilities, either built-in or through user-defined drivers, which is particularly useful for automating antenna pointing during satellite passes. Its interface is designed for ease of use, making satellite tracking accessible even for beginners. First released in 2005, Orbitron 3.71 runs on Windows 9x/Me/2k/XP/2k3/Vista and can operate on Linux via _Wine emulation_, requiring minimal system resources. The software's precision relies on periodic TLE updates, especially for low-Earth orbit objects, to account for orbital decay and maneuvers by satellites like the ISS or Soyuz.

HF Wire Yagi antenna with notes and eznec file on original article of a Portable 3-Band Yagi antenna for 10-15-20 meter band made with wire elements. Include link the original to QST article.

Freeware MSDOS SSTV program by WB2OSZ, Automatic Calibration, Automatic Fine Tuning, Widest Variety of File Types

Download this Microsoft Excel-based converter to import ADIF to Excel table and export the Excel Table to ADIF file format.

The **NW3Z** optimized wideband antenna designs, originally presented at Dayton 2001, detail Yagi configurations for the 20-meter, 15-meter, and 10-meter amateur radio bands. This resource provides access to the design files, likely containing critical parameters such as element spacing, element lengths, and boom dimensions, which are essential for replicating these directional antennas. The designs focus on achieving wide bandwidth, a desirable characteristic for contesters and DXers operating across a significant portion of each band. The content specifically references "nw3z-Antenna-DesignsDownload," indicating that the core information is available as a downloadable file, presumably in a format suitable for antenna modeling software or direct construction. Such files typically include **NEC models** or similar data, allowing for performance analysis and optimization before physical construction. The emphasis on "optimized wideband" suggests design considerations for SWR bandwidth and gain characteristics over a broader frequency range than typical narrow-band Yagis. The resource serves as a direct source for specific, proven antenna designs from a known amateur radio antenna designer, offering practical data for hams interested in building high-performance Yagi arrays for HF.

adsbScope is a freeware Windows application designed for processing _ADS-B_ (Automatic Dependent Surveillance-Broadcast) frames received from a compatible decoder. It identifies aircraft, calculates their real-time positions, and presents flight parameters in both alphanumeric tables and a graphical display. The software interfaces via a virtual COM port, receiving raw frames to provide detailed situational awareness, including a global coordinate grid, continental coastlines, over 4,000 **airport** locations, and major cities. Users can overlay OpenStreetMap tiles and view world state boundaries, with each tracked aircraft rendered with labels showing altitude, speed, heading, squawk code, and flight identifiers. When paired with the adsbPIC-decoder, adsbScope enables advanced hardware control, allowing users to toggle data filters for specific frames like DF17/18/19, adjust analog signal thresholds for reception fine-tuning, and manage system resets or bootloader activation directly from the PC. This functionality provides a customizable toolkit for hobbyist radar listeners, offering a robust alternative to commercial tools for processing aircraft data. The software displays up to **1090 MHz** transponder data and can track aircraft up to 250 nautical miles.

The article "Exploring the World of 10 Meter Beacons" by Ken Reitz, KS4ZR, provides an in-depth look at 10-meter beacon operations, focusing on their utility for propagation analysis. It details FCC Rules part 97.203 governing beacon stations, including license requirements, power limits (under 100 watts), and the specified band segment of 28.200-28.300 MHz for U.S. operations. The content highlights the diversity in beacon construction, from converted CB radios to home-brew QRP transmitters, and discusses the robust operating conditions these 24/7 stations endure. The resource presents several case studies of active 10-meter beacon operators like Ron Anderson KA0PSE/B, Domenic Bianco KC9GNK/B, and Bill Hays WJ5O/B, detailing their equipment, antenna setups, and typical signal report volumes. It also introduces the NCDXF/IARU International Beacon Project, which features 18 synchronized beacons worldwide transmitting on 28.200 MHz at varying power levels (100W, 10W, 1W, 100mW) to facilitate propagation testing. The article also covers the PropNet Project utilizing PSK31 on 28.131 MHz and the 250 Synchronized Propagation Beacon Project on 28.250 MHz. Practical advice for monitoring includes using the RST reporting method, understanding the impact of the solar cycle on 10-meter propagation, and tips for setting up a personal beacon, such as frequency selection and power output considerations. The IY4M Guglielmo Marconi Memorial Beacon Robot on 28.195 MHz is also mentioned for its automatic QSO mode. The article concludes with a list of other resources for 10-meter beacon information.

Vox Recorder is a Windows utility wich allows recording sound from an audio source only when an audio signal is present; its main purpose is to avoid the recording of the silence eventually present at the input.

KG4JJH moxon assembly plan for the 50 Mhz in a pdf file

An easy mod to make the 1st IF of the Icom IC-7600 accessible and connect to a cheap RTL SDR dongle by VE4NSA

A PDF File to download and print, with a table of all menu options with values, default settings, description and a quick reference guide of the front panel menus

The Kenwood TS-950S and TS-950SD HF transceivers are fine radios. However, many, if not all, of them were produced with a design flaw which allows the RG GAIN control to cease function in the presence of a strong signal IF the AGC has been turned OFF

Step by step instructions for setting up N1MM Logger to communicate with the TS-590S using the USB connection

This article will help to unravel some of the mysteries as well as giving useful operating tips to maximize your chances of working that rare station

The Super Check Partial database files provide a list of callsigns used by active contesters. The data comes from Cabrillo logs contributed by contesters themselves. Contributed logs from the past 24 months are used to create the database. These logs are combined and filtered so that they result in a fairly good (but not perfect) list. The files do not contain any QSO data, such as state, CQ zone, Maidenhead Grid Locator, etc. The dta files can be used with CT, WriteLog, TRlog, SD, N1MM Logger, NA, Win-Test, and others

Using the Raspberry Pi to operate Weak Signal Propagation Reporter

This PDF document details the construction of a **70 MHz** Big Wheel antenna, a horizontally polarized omnidirectional array. The design utilizes three full-wave loops, each approximately **2160 mm** in diameter, arranged in a triangular configuration. The resource provides mechanical dimensions for the antenna elements and a comprehensive bill of materials, specifying component quantities and types, such as M8 stainless steel bolts, 15x15x1.5 mm square aluminum tubing for spacers, and 8 mm aluminum rod for the arcs. The central hub is constructed from two 160x160x8 mm aluminum plates, with four 40 mm long polyamide insulators supporting the radiating elements. The feed system incorporates a 50 mm diameter aluminum pipe for mounting and a matching stub constructed from a 120x20x2 mm aluminum sheet, connected via M8x10 mm bolts. The resource includes a diagram illustrating the mechanical dimensions and assembly points, including the N-connector fixing point and the center conductor attachment. The project was published on May 25, 2011, by Peter OE5MPL and Rudi OE5VRL. DXZone Focus: PDF | 70 MHz Big Wheel | Mechanical Dimensions | **2160 mm** loop diameter

The RasHAWK team has used a Raspberry Pi as the basis for a networked RF sensor capable of supporting spectrum monitoring, signal intercept and direction finding (DF) operations.

A bycicle ham radio station setup, with full band coverage

Details the construction of an **HF converter** designed by M1GEO, George Smart, specifically to extend the frequency range of the FunCube Dongle Pro (FCD) for amateur radio reception. The FCD natively covers 64 to 1,700 MHz, but this project enables reception from 0 Hz to 64 MHz by up-converting signals to the FCD's operational range. It employs a **double-balanced mixer** with a 100 MHz local oscillator (LO) to translate incoming HF signals; for instance, a 1 MHz signal appears at 101 MHz within the FCD's passband. The design incorporates a 7th-order Chebyshev low-pass filter with a 62 MHz cutoff frequency at the input to mitigate image frequencies, ensuring cleaner spectral presentation. George provides the schematic, PCB masks, and Gerber files for replication, noting that Far Circuits also offers PCBs. The resource includes test results for the low-pass filter and measurements of LO leakage, identifying -36.8 dBm at 100 MHz as a potential sensitivity concern. M1GEO discusses potential improvements, such as adjusting the mixer's LO drive, adding a balance pot, or incorporating a post-mixer high-pass filter to reduce LO breakthrough. Audio recordings from 40m and 17m demonstrate the converter's performance with WRplus SDR software.

This project is a Software Defined Radio Receiver. It has a frequency range of 24MHz 1.2GHz. It can demodulate AM, FM, USB, LSB with selectable bandwidths of 600, 2400, 2800, 3200 and 6400Hz. Using a simple RTL-SDR Dongle and Raspberry Pi 3 computer using GNU RADIO

The Hermes-Lite is a low-cost direct down/up conversion software defined amateur radio HF transceiver based on a broadband modem chip and the Hermes SDR project. It is entirely open source and open hardware, including the tools used for design and fabrication files. Over 300 Hermes-Lite 2.0 units have been successfully built.

QST article from May 1994 about history of call signs from the very beginning to present system. Article explains call sign allocations, call areas, prefixes for novices and prefixes like K WA WB WD, callsigns during and after the world war II and other curiosities on US Call signs.

The ICOM IC-7610 SDR HF/50MHz Transceiver Basic Manual in English PDF File 13 MB

This article will explain a few of the ways author use an external SDR and Linrad to enhance his K3 experience. Linrad is one of many available SDR receiver programs. The same could be done with any radio that lets you access its IF frequency output. Article from NCJ Nov Dec 2019

From 1921 to 1924, radio amateurs experimented with transmitting across the Atlantic. Everyday Engineering magazine organized the first sending test with English amateurs prepared to listen for signals from the US

Complete microphone wiring handbook for most popular radio transceivers provided by Astatic Microphones.

Master Callsign Database Editor allows to create and modify Super Check Partial database files used by many contesting programs in DTA and SCP formats. The files produced by Master Editor in DTA format can be used with CT, WriteLog, TRlog, SD, and others. The SCP versions of the produced files are for use with Win-Test, N1MM+, and others. Master Editor allows to create a callsign database from a separate log or from a set of logs in the Batch Import mode.

This presentation applies to HF / VHF / UHF antennas and is about 14 different type of antennas suitable for indoor od apartament installations

The Icom IC-7300 is a popular SDR transceiver known for its excellent performance in ham bands. However, users have reported issues with reception reliability outside these bands due to ADC aliasing. This phenomenon occurs when the sampling rate of the radio interacts with frequencies outside the intended range, leading to unwanted signals being received. For instance, when tuned between 30 to 36 MHz, users may inadvertently pick up WFM broadcast signals or PMR communications due to aliasing effects. This guide outlines modifications to improve the IC-7300's performance by addressing the low-pass filter design, which is crucial for reducing interference from these unwanted signals. The proposed modifications involve adjusting the low-pass filter on the PA unit to better attenuate frequencies that cause aliasing. Measurements indicate that the original filter design allows significant signal leakage, leading to false receptions. By implementing the suggested changes, users can achieve a notable reduction in unwanted signals, enhancing the overall functionality of the IC-7300. While the modification requires careful soldering, the benefits in performance make it a worthwhile endeavor for serious operators looking to optimize their SDR experience.

This project enhances Arjan te Marvelde's uSDR-pico by integrating a waterfall display feature. By adding an ILI9341 240x320 2.4" TFT display and modifying the software, the goal is to provide a panadapter to the existing transceiver. Initially developed with Visual Studio, the code was later migrated to Arduino IDE for Raspberry Pi Pico compatibility. The focus remains on preserving the original software, primarily enhancing the dsp.c file for waterfall implementation.

Receiving **GOES-16** and **GOES-17** weather satellite imagery requires a specific hardware and software configuration, detailed in this practical guide. The author outlines the necessary components, including a Raspberry Pi, an RTL-SDR dongle, a suitable LNA with SAW filter for 1.69 GHz, and a parabolic grid antenna. This setup enables direct reception of high-resolution weather data, a fascinating aspect of amateur radio satellite operations. The installation process begins with preparing the Raspberry Pi, followed by updating the system and installing essential dependencies like `git`, `build-essential`, and `cmake`. A critical step involves compiling and installing `librtlsdr` from source, ensuring proper driver setup and blacklisting conflicting DVB drivers. The guide then walks through testing the RTL-SDR dongle to confirm device recognition and troubleshoot common issues like USB power or driver installation problems. Finally, the instructions cover cloning and building `goestools`, a software suite essential for processing the satellite signals. This compilation, while time-consuming on a Raspberry Pi, is crucial for decoding the raw data into usable imagery. The guide concludes with the initial steps for creating the `goesrecv.conf` configuration file, preparing the system for active satellite reception.

Raspberry Pi Telemetry Station project by Burns Fisher, WB1FJ , Chris Thompson G0KLA/AC2CZ. A step by step guide on Building a Fox-In-A-Box The Easy Way, A Prebuilt SD Card Image or from scratch.

This page provides instructions and links to download the latest APK version of APRSdroid and the Mobile HUD for ham radio operators. It also includes information on manually granting storage permissions for offline mapping files on Android 11+ devices. The page offers guidance on setting up and using offline maps in APRSdroid with OpenStreetMap.org. Various mapping options and providers are mentioned, along with a recommendation to support the author on Patreon. Overall, this resource aims to assist hams in effectively utilizing APRSdroid for their amateur radio activities.

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.

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.

Chokes and isolation transformers are essential for receiving antennas to mitigate common mode current, which induces noise and interferes with signal quality. Common mode chokes, formed by winding feedline through ferrite cores, block unwanted current effectively. Proper selection of core material and winding turns ensures resonance near the operating frequency, reducing interference. Isolation transformers further minimize interference, crucial for multi-transmitter stations.

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

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.

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.