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The G5RV antenna, with an overall length of **31.10m (102ft)**, functions as a 3/2-wave on 20 meters when installed horizontally at 12m (39ft), exhibiting a resonant frequency of 14.150MHz and an approximate resistance of 80 ohms. Its 10.36m (34ft) stub line, designed as a 1/2-wave on 14.150MHz with a 0.97 velocity coefficient, acts as an impedance transformer across other bands, aiming for multiband operation without traps. On 20m and higher frequencies, the G5RV demonstrates improved gain compared to a standard dipole, attributed to the _collinear effect_ from multiple 1/2-waves along the wire. The original design sought a multiband solution for limited spaces, often requiring an Antenna Tuning Unit (ATU) for effective operation across bands like 80, 40, 30, and 20m, particularly with modern solid-state PAs. Variants, such as the F8CI modification, incorporate a 1/4 current balun at the stub line's base for symmetrical-to-asymmetrical transition, known as a _remote balun_. Proper flat-top or inverted-V installation is critical for maintaining symmetry and collinear gain, with inverted-V apex angles below 120° progressively diminishing higher-band performance.

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.

Demonstrates the construction and on-air performance of the _NB6Zep_ antenna, a modified 20-meter Extended Double Zepp design optimized for multi-band operation from 40 through 10 meters. The resource covers basic design principles, including dimensions of 66 feet horizontal and 5 feet vertical elements, and specifies open ladder line or TV twin lead for the transmission line. It details material selection for low-cost wire antenna construction, such as 18 AWG wire for the legs and ceramic or plastic insulators, along with practical tips for soldering connections and insulating against moisture. The author, NB6Z, shares insights from extensive _EZNEC_ modeling to optimize the antenna's total length for a 40-meter half-wave dipole footprint and feed line length for direct tuner connection. The article presents field results, including successful _PSK31_ contacts from Oregon to the East Coast on 40 and 30 meters with 50 watts, even at a low height of 6 feet. It provides detailed performance characteristics for each band, noting the _NB6Zep_'s highest gain (over 3 dB) and sharp, medium-angle lobes on 20 meters, which yielded strong DX reports to locations like Korea, Japan, and Argentina. For 17 and 15 meters, it describes a butterfly-like pattern with broad lobes, while 12 and 10 meters exhibit narrow, directional lobes in an "X" configuration. The author also shares personal experiences operating successfully for over a decade in an antenna-restricted environment using the NB6Zep and other stealth wire antennas.

Two live MP3 audio streams provide real-time reception of meteor forward scatter signals, allowing listeners to hear radar echoes from meteoroid disintegration. The system operates on **67.25 MHz**, utilizing an Icom PCR-1000 receiver with a 6-element Yagi antenna pointed skyward. This setup detects reflections from ionized meteor trails created at altitudes of 80 to 130 km, using distant Channel 4 TV transmitters in the southeastern USA as signal sources. Scientists Rob Suggs, Bill Cooke, and Jeff Anderson of the Marshall Space Flight Center Engineering Directorate developed this experimental radar to monitor near-Earth meteoroid activity. A typical day yields about one meteor ping per minute, with significantly higher rates during meteor showers. The optimal listening period is generally around dawn, from 0800 to 1400 UT, due to Earth's orbital motion encountering more space dust on the dawn side. The system's **CW demodulator** processes the 67.250 MHz signal, presenting it at approximately 700 Hz with a 3 kHz bandwidth and AGC off, inverting the passband for Doppler shift analysis.

PA3FWM's software defined radio (SDR) page documents his extensive hardware and software development efforts between 2004 and 2009. Initial experiments utilized a direct conversion receiver with 90-degree phase difference, feeding a PC soundcard at 48 kHz sample rate, covering 24 kHz of spectrum around a 7080.5 kHz local oscillator. This setup, similar to AC50G's QEX 2002 article, allowed for basic I/Q signal processing to distinguish signals above and below the LO frequency. Limitations included fixed crystal frequencies, 16-bit dynamic range, and narrow bandwidth. Subsequent hardware iterations aimed for enhanced performance, incorporating external 24-bit ADCs with 192 kHz sample rates, connected via 10 Mbit/s Ethernet. A **MC145170-based PLL** and programmable octave divider provided a 58 kHz to 30 MHz tuning range. The **Tayloe mixer** was employed, with differential outputs feeding a PCM1804 ADC. An ATmega32 microcontroller handled serial data conversion to Ethernet frames, though without CRC calculation due to processing constraints. Later designs integrated AD7760 2.5 Msamples/second ADCs and a Xilinx Spartan-3 FPGA, enabling direct reception of 0-1 MHz spectrum and eventually 2.5 MHz bandwidth across the shortwave spectrum. Software was refactored to use an initial 8192 non-windowed FFT for efficient high-bandwidth processing. The project culminated in a two-way QSO on 21 MHz using the developed hardware and software, demonstrating transmit capabilities with a D/A converter. The system exhibited a 2.5 MHz wide spectrum display and a zoomed 19 kHz display, capturing signals like ionospheric chirp sounders and RTTY contest activity. Challenges included noise leakage from digital circuitry and cooling for high-power dissipation components.

Operating amateur radio satellites effectively requires precise knowledge of their orbital mechanics and pass times. Gpredict, a real-time satellite tracking and orbit prediction application, addresses this need by allowing operators to monitor numerous satellites simultaneously. It displays critical data such as position and pass details through various visualizations, including lists, tables, maps, and _polar plots_. Unlike many other satellite tracking programs, Gpredict introduces the concept of visualization modules. These modules enable users to group satellites and configure each group independently, offering unparalleled flexibility in how orbital data is presented. This modular approach supports tracking satellites from multiple observer locations concurrently, which is particularly useful for stations with diverse antenna setups or remote operations. Originally a GUI client for John Magliacane's _Predict_ program, Gpredict evolved to integrate its own tracking code for improved performance. The software is distributed under the GNU General Public License, ensuring it remains free and modifiable for the amateur radio community.

Lets you listen to your scanner across your own network, or via the internet. Shoutcast/ICEcast compatible broadcasting for Uniden and GRE scanners. Broadcast your audio from your PC. ScannerCast is a specialized broadcasting solution that enables users to stream scanner audio feeds over the internet. This software supports both Uniden and GRE scanner models with tag information capability, while providing audio-only functionality for other scanners. Compatible with standard streaming protocols, ScannerCast allows remote listening via common media players without requiring specialized client software. The program features customizable tag display, adjustable bit rates, and seamless integration with Radio Reference. Its efficient design replaces multiple legacy applications while improving tag/audio synchronization. ScannerCast operates efficiently across various Windows environments, making remote scanner monitoring accessible from any location with internet connectivity. Scannercast is no more supported or developed by it's author.

The document details the construction of a compact, two-element Quad antenna specifically designed for the 10, 12, and 15-meter HF bands, featuring a single feedline for all three bands. It provides specific dimensions for the driven element and reflector loops, along with boom length and spacing, emphasizing a **0.12 wavelength** spacing between elements. The design incorporates a gamma match for impedance transformation and uses PVC tubing for spreaders, aiming for a lightweight yet robust structure suitable for portable or restricted-space operations. Performance measurements indicate a forward gain of approximately **6 dBd** on 10 meters and a front-to-back ratio of _20 dB_ on 15 meters, demonstrating effective directivity and signal rejection. The antenna exhibits a VSWR below 1.5:1 across the target bands, achieved through careful tuning of the gamma match. This compact Quad offers a viable directional solution for HF DXing and contesting, particularly where full-size Yagis are impractical.

Ballistic simulator "Orbit" allows the physical principles of the motion in the gravitational field of the Earth to be demonstrated and learned. You can calculate with this program the ballistic trajectories of the thrown bodies and orbits of spacecrafts and visualize the astroballistic situation on the flat map of the world and on the rotating globe in the real time

Demonstrates the capabilities of CW_Shark, a dedicated 32-bit Windows application for Morse code operations. This software facilitates the analysis, decoding, and encoding of CW signals, providing hams with a versatile tool for various aspects of amateur radio communication. It supports four distinct modes: Decode Only, Keyboard QSO, Straight or Paddle Key QSO, and Straight or Paddle Key Practice, catering to different user needs from passive listening to active keying. Operators can utilize the Decode Only mode for signal analysis, while the Keyboard QSO mode allows for text-based interaction. The Straight or Paddle Key QSO mode offers a direct interface for traditional keying, enabling real-time communication. For skill development, the Straight or Paddle Key Practice mode provides a structured environment to hone Morse code proficiency. CW_Shark integrates essential functions for CW enthusiasts, supporting both learning and active participation in Morse code exchanges. Its focused design aims to assist operators in mastering and enjoying the art of _CW communication_.

Codec2, an open-source speech codec, targets low bit rate voice communication, specifically designed for digital radio applications operating within constrained bandwidths. The project focuses on achieving intelligible speech quality at data rates around 2400 bits per second, a critical parameter for efficient spectrum utilization in amateur radio. Its development addresses the need for robust voice transmission over channels where higher bit rate codecs would be impractical or inefficient. The resource details the technical specifications and implementation aspects of Codec2, including its underlying algorithms and performance characteristics. It provides insights into how the codec processes speech to achieve its low bit rate, outlining the various coding schemes and their impact on voice fidelity and error resilience. The information presented allows radio amateurs and developers to understand the codec's operational principles and its suitability for integration into custom digital communication systems. Applications for Codec2 extend to digital voice modes on HF and VHF bands, enabling more users to share limited spectrum resources. The project's open-source nature facilitates community contributions and widespread adoption, fostering innovation in digital amateur radio. It represents a significant effort to provide a freely available, high-performance speech coding solution for the amateur radio community.

Optimizing DX chasing efforts, this software provides a refined approach to monitoring the DXCluster. It allows operators to configure specific filtering criteria, ensuring that only relevant DX spots are displayed, thereby reducing clutter and focusing attention on desired entities or bands. The application integrates alarm functionalities, notifying the user when a spot matching their predefined parameters appears on the cluster, which is particularly useful for working rare DX or specific band slots. Spot supports both macOS and Windows operating systems, offering a cross-platform solution for a broad user base. Its design emphasizes user control over the displayed information, moving beyond a simple stream of cluster data to an actionable intelligence system for DXers. This client aims to streamline the process of identifying and pursuing DX opportunities. While the software was previously a commercial product, the developer, K3NC, has retired and made registration files for DXBase 2007 available for free, along with a utility to generate registration keys for that specific version. This allows continued use of the DXBase 2007 logging software, though it's important to note the 64-bit OS compatibility modification required for generated registration files.

The Moxon Beam, introduced by L. Moxon (G6XN), is a compact 2-element Yagi featuring a radiator and reflector with reduced dimensions, approximately 75% the size of a full-size beam. This design utilizes bent element ends for capacitive loading, which is superior to inductive loading with coils, resulting in greater bandwidth and lower losses. DK7ZB details that while the gain is slightly lower (0.5-0.7 dB) than a full-size beam, the _Moxon_ offers an exceptional front-to-back (F/B) ratio of 30 dB or more on its design frequency, surpassing other 2-element beams. The article provides specific dimensions for building wire _Moxon_ antennas for bands from 30m down to 10m, and also mentions a 2-m-Moxon. Construction guidance includes using fishing rods for lightweight spreaders and an aluminum tubing spider for support. The resource highlights the utility of _Moxgen_ by AC6LA, a freeware program that simplifies Moxon beam design and generates EZNEC output files for further analysis and tapering modifications. DK7ZB emphasizes that the design frequency should be set at approximately one-third from the band's beginning to optimize SWR performance, as SWR tends to rise more significantly below the design frequency. The bandwidth for SWR < 1.5 is noted as sufficient for ranges like 28.0-28.7 MHz and 21.0-21.45 MHz when constructed with aluminum tubes, though wire beams exhibit a narrower bandwidth.

Codec2 is an open source low bit rate speech codec designed for communications quality speech at around 2400 bit/s. Applications include low bandwidth HF/VHF digital radio.

Operating on the 2200m band (135.7-137.8 kHz) often presents challenges for amateur radio transceivers, which typically exhibit poor receiver performance at these very low frequencies. This project addresses the issue by providing a design for a dedicated 137 kHz antenna preamplifier, specifically tailored to improve signal reception for radios such as the _Yaesu FT-817_. The preamplifier circuit utilizes a low-noise FET input stage, crucial for minimizing self-generated noise and maximizing the signal-to-noise ratio from weak LF signals. The design includes a detailed schematic, component values, and construction notes, enabling homebrewers to build a functional unit. The goal is to achieve significant gain, making the faint signals on 2200m more discernible and improving overall band usability. Key design considerations include impedance matching to typical antenna systems and ensuring stable operation across the narrow LF segment. The circuit aims for a **low noise figure** and sufficient amplification to overcome the inherent limitations of general-purpose HF transceivers when operating below **200 kHz**.

The X80 multi-band HF vertical antenna, a commercial iteration of the Rybakov design, exhibits a physical length of 5.5 meters, or approximately 18 feet, and is constructed from aluminum tubing. It operates as a non-resonant vertical, requiring an external antenna tuner for impedance matching across its intended operating frequencies. The antenna's design incorporates a 1:4 UNUN at its base, facilitating a nominal 50-ohm feed point impedance for the coaxial cable. Performance observations indicate effective operation on 40 meters, 20 meters, 15 meters, and 10 meters, with reduced efficiency on 80 meters and 160 meters due to its relatively short electrical length for these lower bands. Comparative analysis with a G5RV dipole and a half-wave end-fed antenna reveals the X80 offers a lower take-off angle, beneficial for DX contacts, particularly on the higher HF bands. Field tests conducted with an Icom IC-706MKIIG transceiver and an LDG AT-100ProII autotuner demonstrate the X80's ability to achieve acceptable SWR across 80m through 10m. The antenna's compact footprint and ease of deployment make it suitable for restricted spaces or portable operations, though its performance on 80 meters is noted as a compromise compared to full-size resonant antennas.

Codec2 is an open source low bit rate speech codec designed for communications quality speech at 2400 bit/s and below. Applications include low bandwidth HF/VHF digital radio and VOIP trunking.

A 200 kHz bandwidth digital transmission system for image transfer in the Amateur Service is under development, specifically targeting VHF allocations. John B. Stephensen, KD6OZH, leads this project under an FCC Special Temporary Authority (STA) valid until September 10, 2006, authorizing emissions up to 200 kHz bandwidth in the 50.3-50.8 MHz segment. Current regulations typically limit bandwidths to 20 kHz on VHF amateur bands, making this STA crucial for testing wideband digital modes. The modem, a modified **OFDM** (Orthogonal Frequency Division Multiplexed) unit, was initially tested on the 70-cm band. It splits a high-rate data stream into multiple low-rate subcarriers to mitigate multipath echoes. The system uses a DCP-1 card with a Xilinx XC3S400 FPGA and Oki Semiconductor ML67Q5003 microcontroller. The transmitter, located at 36d 46m 30s N, 119d 46m 22s W, generates 150 WPEP into an 8 dBi gain vertical antenna, while the mobile receiver uses a Ham-stick. Three data formats for 50, 100, and 200 kHz channels are being tested, with encoded data rates of 96, 192, and 384 kbps. Verilog code for the VHF OFDM modem is 95% simulated, with modifications from the UHF version including increased filter coefficient precision and a change from Ungerboeck **TCM** to BICM for improved performance over fading paths. Final tests will involve one-way over-the-air measurements of bit error rates and coverage area.

The article presents a detailed examination of 40-meter wire antenna performance, specifically focusing on the impact of antenna height on gain and radiation patterns. It quantifies how a 40-meter dipole at 1/8 wavelength above ground exhibits a high-angle radiation pattern, while raising it to 1/2 wavelength significantly lowers the take-off angle, improving DX capabilities. The author, VE3VN, leverages _EZNEC_ simulations to illustrate these changes, providing visual representations of the antenna's lobe structure at different elevations. Comparing a single dipole to a two-element wire array, the analysis shows that a 2-element array at 1/4 wavelength height can achieve **3.7 dBd** gain, outperforming a single dipole at the same height. This gain is further enhanced to **5.7 dBd** when the 2-element array is elevated to 1/2 wavelength, demonstrating the practical benefits of optimizing both element count and height for improved signal strength and directivity on the 40-meter band. The findings offer practical insights for hams seeking to optimize their wire antenna installations.

Understanding the operational impact of Broadband over Power Line (BPL) on amateur radio communications is crucial for any radio amateur, especially given the potential for significant radio frequency interference (RFI). This ARRL tutorial delves into the technical aspects of BPL, explaining how the technology operates by transmitting data over existing electrical power lines, which can inadvertently radiate broadband noise across various amateur bands. My own field experience, particularly on the lower HF bands, has often involved tracking down noise sources that exhibit characteristics consistent with BPL emissions, making this a pertinent topic for maintaining clear receive conditions. The resource further details the specific FCC rules and regulations implemented to restrict BPL deployment. These regulations aim to protect licensed radio services, including amateur radio, from harmful interference. It outlines the technical standards and operational limitations imposed on BPL systems to minimize their impact on the electromagnetic spectrum, a critical aspect for contesters and DXers alike. For those engaged in RFI mitigation, the tutorial provides a foundational understanding of the regulatory framework that can be leveraged when addressing BPL-related interference issues. It serves as a valuable reference for hams seeking to comprehend the technical challenges and regulatory solutions surrounding this pervasive noise source.

The program can be used to calculate inductors (coils) and their number of turns on ferrite cores, ferrite shells and air coils. These can be used for baluns, Ununs, bandpass filters, low pass filters, resonant circuits, and more. The technical specifications of the cores are already integrated in the program. Application is free and runs on Windows 32 bit versions only. To make it run on Windows 10 64 bit need to be unzipped in a single folder.

The _Fuji-OSCAR 20_ (FO-20) amateur radio satellite, launched over six years prior, continues to operate reliably, despite a gradual decrease in its Nickel-Cadmium storage battery capacity and solar cell degradation. The satellite's power system can still supply approximately **10 W**, enabling operations. During the non-eclipse period, typically from mid-June through March, the satellite experiences a 0% eclipse rate, ensuring sufficient power generation. This allows for the potential operation of the onboard BBS, which had been previously suspended due to concerns about power shortages. An "eclipse rate" refers to the proportion of time a satellite spends in the Earth's shadow during each orbit. When the satellite's orbital plane is perpendicular to the sun's direction, the eclipse ratio becomes zero, meaning continuous solar illumination. Understanding these eclipse periods is crucial for managing satellite power budgets and scheduling operations, particularly for power-intensive functions like the BBS, which can now be considered for activation during periods of sustained solar exposure.

The 2200-meter band (135.7-137.8 kHz) presents unique challenges for amateur radio operators due to its narrow 2.1 kHz bandwidth, low signal levels, and high noise. W1TAG explores various transmission modes suited for this demanding environment, highlighting that traditional voice modes like SSB and AM are impractical. Plain old CW serves as the baseline, demonstrating effectiveness across different modes, though signal-to-noise ratio (SNR) significantly limits practical speeds. The article notes that reducing CW speed below 5 WPM can improve copy, especially with computer-aided spectrum analysis software capable of decoding signals too weak for human ear reception. QRSS, or "CW sent slowly enough that speeds are best expressed in seconds per dot," is a key mode for LF work, with examples ranging from 3 seconds/dot to extreme 240 seconds/dot transmissions. _Argo_ by I2PHD is mentioned as a simple program for QRSS, enabling reception of signals like BRO, a Part 15 beacon, at a distance of **1100 miles**. Other modes discussed include Dual Frequency CW (DFCW), which uses frequency shifts to distinguish dots and dashes, and Binary Phase Shift Keying (BPSK), a phase modulation technique employing 0 to 180-degree phase flips. WOLF (Weak-signal Operation on Low Frequency), a specialized BPSK form by KK7KA, encodes 15-character messages into 960-bit packages, taking 96 seconds to transmit, and has demonstrated successful reception over **672 seconds** for a message from a 1-watt beacon. Further modes include PSK, FSK variations like JASON and MSK, and graphical modes such as Hellschreiber and Chirped Hell. The article concludes with a practical chart comparing the time required to send a simple message like "WD2XES FN42CH " across these diverse LF modes, offering valuable insights for operators planning contacts on the low bands.

This DIY vertical multi-band Windom antenna offers a practical and effective solution for amateur radio enthusiasts seeking a versatile and compact antenna for HF communications. Its simplicity of construction, multi-band capability, and favorable performance make it a valuable addition to any radio shack. The article provides detailed instructions on constructing the antenna and balun, along with diagrams and component specifications. Field tests demonstrated successful contacts with stations across Europe and North America on 14, 18, and 28 MHz. The antenna exhibited comparable performance to a W3DZZ dipole and outperformed a Cobweb antenna on 18 MHz. Low noise levels were observed, effectively suppressing background noise.

Operating Free DV, the open source digital voice codec for HF, allows any SSB radio to be used for low bit rate digital voice.

High Speed Multimedia (HSMM) radio, as introduced by John Champa, K8OCL, represents a significant advancement in amateur radio's digital capabilities, moving beyond traditional keyboard modes like packet radio. This initiative, driven by ARRL's Technology Task Force, focuses on developing high-speed digital radio networks capable of up to 20 megabits per second. HSMM primarily facilitates digital voice (DV) and digital video (ADV), enabling real-time video transmission from emergency scenes to an EOC without expensive ATV gear, often requiring only a laptop, a PCMCIA card, a digital camera, and a small antenna. The working group's initial efforts concentrate on cultivating microwave skills within the amateur community to build and support portable and fixed high-speed radio-based local networking, or **RLANs**. These networks prove invaluable for RACES and ARES organizations, as well as homeland security and other emergency communications. Field Day exercises and simulated emergency tests (SETs) are encouraged to hone skills in rapid site surveys and deploying broadband HSMM microwave radio networks, with examples like linking Field Day logging stations or antenna test results at the Midwest VHF-UHF Society Picnic 2003. Getting started with HSMM often involves adapting off-the-shelf **IEEE 802.11** (WiFi) equipment to comply with amateur radio regulations, typically operating in the 2.4 GHz ISM bands. While consumer WiFi gear has range limitations under Part 15 rules, proper setup under amateur regulations can extend coverage significantly, with test networks like the Hinternet achieving 5-15 mile ranges at 54 M bit/s using small mast-mounted dish antennas. Careful selection of equipment with external antenna ports, high transmit power, and low receive sensitivity is crucial, along with using low-loss coaxial cable like LMR-400 for optimal performance at these frequencies.

DXChrono Desktop presents a comprehensive suite of real-time amateur radio data, including NOAA solar indices, HF band conditions, and a worldwide _F5LEN tropo_ overlay for VHF openings. It integrates live spots from Telnet DX Cluster, PSK Reporter, and Reverse Beacon Network, displaying them on a dynamic 3D globe or 2D flat map. Additional features include aurora and MUF layers, QTH display with optional cities and grid/CQ/ITU layers, and dedicated support for SOTA and POTA activations. The software also offers a Watch List for callsign alerts and Sun/Moon Az/El widgets for satellite and EME operations. The application provides extensive contest and logging context through integration with _N1MM Logger+_ UDP, Cloudlog API, QRZ Logbook, and ADIF file support, allowing recent QSOs to be mapped directly. A Special Event mode is available for club stations, enhancing field day operations. DXChrono Desktop runs on Windows, macOS, Linux, and Raspberry Pi 4/5, requiring a 64-bit OS and at least 4 GB RAM for optimal performance, distinguishing it from simpler HamClock-style appliances.

The **Nilex Morse Tutor** is an HTML5 web application designed to teach Morse code reception, adapting to user proficiency by adding new characters as readiness is detected. It prioritizes practice on less familiar letters, numbers, symbols, words, and phrases, while minimizing repetition of already mastered elements. The program offers multiple learning orders, including "Q7ZG..." (Ward/Jim's), "KMRS..." (PU5EPX/Koch), "KMUR..." (lcwo.net), "AENT..." (CWops CW Academy), "TEAN..." (Stephen C Phillips), "ANET..." (Vic VE3YT), and "ETI5..." (Ham Whisperer), alongside an alphabetical option. Users can customize the learning experience by enabling or disabling automatic progression, and selecting specific content categories such as numbers, symbols, words, phrases, QSO bits, Ham Radio Bands, X+Y=Z math, and units. Audio settings are adjustable for volume, speed (WPM), tone frequency, and keyshape/keying envelope, allowing for a personalized auditory environment. The interface provides visual feedback with blue bars indicating practice emphasis and gray bars for reserved characters, with clickable bars for manual character selection. Developed by "Nosey" Nick Waterman, VA3NNW, this tutor is based on earlier versions by Jim Wilson and a 1977 QST article. A significant October 2019 rewrite incorporated a new WebAudio sound library by AwesomeAidenW, improving offline functionality and mobile support. The content library was expanded to include 3000 top Google words, 2284+ General Service List words, ISO country codes, capital cities, US states, Canadian provinces, UK counties, common names, periodic table elements, quotes, Q-codes, electronic components, ham abbreviations, and example call signs. The software is distributed under the GNU GPL V2 license.

The DX Jungle SatTracker is an interactive online tool designed for real-time amateur radio satellite tracking. It incorporates live Doppler correction, AMSAT satellite status, and pass predictions for various active amateur radio satellites such as ISS, SO-50, FO-29, and RS-44. The platform calculates real-time uplink and downlink frequencies, adjusting for Doppler shift, and displays satellite footprints and orbital paths on a map interface. Users can select specific satellites and input their grid square for localized pass predictions. This service integrates WebSDR support, allowing users to listen to satellite passes live without requiring a physical radio, and offers Companion radio control capabilities. Orbital data is sourced from CelesTrak, while radio frequencies are derived from AMSAT and SatNOGS. The interface provides options to filter for FM repeater-only satellites and displays active passes, ordered by the next available pass, facilitating timely operational planning for satellite enthusiasts.

For amateur radio operators interested in satellite reception, SatDump provides a comprehensive software solution for acquiring and processing live data from various orbital platforms. This general-purpose application handles all stages from the raw satellite transmission to the generation of usable products, supporting a wide array of _Software-Defined Radio_ (SDR) devices such as RTL-SDR, Airspy, and HackRF across Linux, macOS, Windows, and Android operating systems. It enables hams to decode and process signals from over 90 satellites and probes, including NOAA 15-18-19, Meteor-M, GOES, and Metop, facilitating live decoding of APT, LRPT, HRPT, LRIT, and HRIT links. The software's capabilities extend beyond basic image reception, allowing for the output of calibrated and georeferenced L1b products, including Sea Surface Temperature and Microphysics, which are suitable for scientific analysis. SatDump's robust DSP system is extensible, offering advanced users the ability to develop new RF links or test hardware TX chains using its _DSP Flowgraph_. Thousands of hams utilize SatDump to receive stunning real-time pictures and data, with the software capable of producing L1b products from more than **five satellite constellations** almost as fast as the satellite transmits the data.

A dual insert microphone design for the Icom IC-7300 transceiver utilizes a **Besson BZ2400 M4 Rocking Armature** insert for frequencies from 500 Hz to 3 kHz, exhibiting a rising response of approximately 11 dB. A generic Electret Condenser insert, powered by the transceiver's microphone line, covers the low-frequency range from 100 Hz to 500 Hz. A Low Pass Filter is incorporated after the Electret insert to prevent frequency overlap, and a pre-set potentiometer (VR1) adjusts the low-frequency response, balancing the output of both inserts. The design emphasizes a "Close Talking" arrangement and addresses audio "colorization" by housing the Besson insert in a thick rubber holder with a foam boot, separate from the circuitry, with the Electret insert also wrapped in a foam boot. Critical importance is placed on using the correct BZ2400 M4 insert with 12 holes in its face plate. The frequency response table for the BZ2400 M4 insert shows 0 dB at 500 Hz, rising to +11 dB at 3000 Hz, while the Electret insert with the Low Pass Filter provides 0 dB at 100 Hz, rolling off to -9 dB at 500 Hz and -50 dB at 3000 Hz. This combination ensures a broad, balanced audio spectrum for SSB operation. The project includes a circuit diagram, a comprehensive parts list detailing components like a 1 Henry iron-cored inductor (L1) and various capacitors, and a board layout within the metal tube. The completed unit provides a tailored audio profile for the IC-7300, enhancing transmit audio quality.

SDR Television v1.0 operates as a DVB-S2 / AAC / H264 / H265 program, specifically engineered for QO-100 satellite Digital Amateur Television (DATV) operations. It provides a full-duplex solution on modern x86 computers running Windows 10 or 11 (64-bit, 8+ cores, AVX2 support recommended), leveraging DLLs from _SDR Console_ for control of devices like _Pluto_ and _LibreSDR.TV_. The software requires installation of the SDR Radio kit for wideband mode support. Initial development focused on a proof-of-concept for QO-100, with future enhancements planned to include H266 / AV1 / Opus codecs and an improved cross-band user interface. The current stable release functions reliably for QO-100 DATV. Users must install the SDR Radio kit, followed by the SDR Television kit, into the same directory. Support inquiries are handled via the SDR-Radio.com mailing list, ensuring direct assistance for operational questions.

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.