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The W5GI Mystery Antenna is a versatile and easy to build multi-band wire antenna designed for amateur radio operations. It covers frequencies from 80 meters to 6 meters, making it suitable for a wide range of operating conditions. The antenna features a low feed point impedance, allowing for easy matching with most radios, whether or not an antenna tuner is used. Its construction is straightforward, requiring only two vertical supports approximately 130 feet apart, making it ideal for hams without towers. Users have reported excellent performance, particularly on the 20-meter band, where it outperforms similar designs like the G5RV. This antenna is unique in its design, incorporating three half waves in-phase on 20 meters, resulting in a six-lobe radiation pattern. Despite its effective performance, the antenna is challenging to model, which adds to its mystique. The W5GI Mystery Antenna has gained popularity among amateur radio enthusiasts worldwide, with many users praising its ease of construction and effectiveness. Whether you're a beginner or an experienced operator, this antenna offers a fun and rewarding project that can enhance your HF capabilities.

Cubic quad antennas are renowned for their high gain, excellent front-to-back ratios, and low angles of radiation, making them a popular choice among amateur radio operators. This resource provides detailed designs for constructing cubic quads optimized for 2, 6, 10, 12, and 15 meter bands. The lightweight structure can be easily built using fiberglass tubes and central hubs, allowing for portability and ease of assembly. The article discusses the specific dimensions and configurations required for both HF and VHF applications, emphasizing the importance of proper spreader lengths and boom dimensions. It also highlights the challenges of assembling larger cubic quads in limited spaces, offering practical solutions for hams with smaller backyards. With a focus on multi-band operation, this guide serves as a valuable resource for both novice and experienced operators looking to enhance their antenna systems.

This resource provides access to the 59+ software collection, specifically highlighting the **59+ CW** module. The software enables the generation of Morse code signals for transmission through a COM port to a transceiver, or for audio output via a computer speaker, facilitating both keying and listening practice. Users can customize various parameters, including CW speed, tone frequency, dash/dot ratios, and PTT line delay, alongside defining keyboard shortcuts for common QSO fields such as callsign, QTH, name, and RST. The collection also includes the 59+ Logbook, which operates smoothly on Windows XP according to testing notes, though the CW application experienced startup issues on the same OS. The software was originally designed for older Windows operating systems, specifically Windows 95, 98, ME, and 2000. It is noted that the original idealog.net site is no longer active, and development for the 59+ suite appears to be discontinued. Analyzer and converter modules within the collection require registration and do not function in trial mode.

The Racal VRM-5080 VHF FM Radio Transceiver, designed for military vehicle installation, operates across the 30 to 76 MHz frequency band with 50 Watts of output power. This unit, along with other featured items like the DOM-410 Geiger Counter and the RT-524/VRC VHF Vehicle Radio Station, represents the core offerings of Army Radio Sales Co. The site provides detailed technical specifications for each product, including frequency ranges, power output, channel spacing, and operational voltage, catering to collectors and restorers of vintage military communications gear. Beyond product sales, the website serves as a repository for historical information, offering access to military radio manuals, articles, and thousands of pictures. Resources such as the SCR-694 / BC-1306 Radio Signal Corps Training Film and TM 11-2715 Installation of Radio Equipment in 1944 Jeeps are available. The platform also hosts a free classifieds section for users to advertise their military radio needs and offers insights into related military vehicle projects. Additional content includes information on the STR37E VHF Aircraft Radio Transceiver, operating from 116.00 MHz to 135.95 MHz, and the R-442/VRC VHF Vehicle Radio Receiver, covering 30-75.95 MHz. The site also features articles on topics like the Ukrainian Expedition and data plates for military Jeeps, broadening its appeal to military history enthusiasts.

Galaxy DX 47HP and DX 99V2 models are highlighted, showcasing the manufacturer's current offerings in both amateur and Citizens Band radio transceivers. The site details several amateur models, including the DX 29HP, DX 44HP, DX 55HP, DX 98VHP, DX 33HP2, and DX 94HP, catering to different operational needs and power levels. For CB operators, a range of models like the DX 2547, DX 979, and DX 929 are presented, with specific features such as _StarLite_ front panel lighting for low-light conditions, as seen on the DX 929 and DX 979. The DX 979 is noted for its compact form factor and SSB capability, making it suitable for installations where space is a constraint. Conversely, larger models like the DX 939, DX 949, and DX 959 are available for those with more room, offering features such as blue lighting and integrated frequency counters. The DX 939, for instance, combines aesthetic appeal with functional design, providing clear readouts and robust audio performance. A downloadable CB radio shopping guide is also offered, enabling users to compare Galaxy's product specifications against other radios on the market, facilitating informed purchasing decisions.

Capturing intermittent radio transmissions efficiently requires a robust audio recording solution that can intelligently manage disk space. Scanrec, a freeware Windows application, addresses this by providing a **Voice Operated Exchange (VOX)** control feature, enabling the recorder to activate only when audio signals exceed a user-defined threshold. This functionality is particularly effective for **FM communications** due to their strong squelch characteristics, minimizing recordings of static or noise. The software supports recording radio communications, air traffic control, and infrequently active channels, preserving disk space by pausing when no sound is detected. It incorporates an anti-clipping feature to ensure the beginning of audio events is not lost, a common issue with mechanical VOX systems. Output files are saved in WAV format, compatible with standard Windows Media Player. Scanrec operates on older Windows systems including Win95, Win98, NT, W2000, and XP, requiring minimal resources like a 486 PC, 4 MB RAM, and a sound card with line or microphone input. While optimized for FM, its VOX gate can be challenging to set for HF ham bands and World Band radio due to their poorer signal-to-noise ratios.

FlexRadio Systems delivers the first truly open source Software Defined Radio transceiver for Amateur Radio use. Receive Only versions are also available for non Amateur Radio applications. Read the SDR Articles and the SDR-1000 Product Information.

Retrospective of a mark now disappeared. Jumbo, Multimode, Concorde, Puma, Viking. Photographs, diagrams, adjustments etc.

CW Skimmer 2.1 employs a high-sensitivity CW decoding algorithm based on Bayesian statistics, enabling simultaneous decoding of up to 700 CW signals within a receiver's passband on a 3-GHz P4 system when paired with a wideband receiver. The software features a fast waterfall display with sufficient resolution for visual Morse Code interpretation, automatically extracting and labeling callsigns on the waterfall traces. Extracted callsigns are exported as DX cluster spots via an integrated Telnet cluster server. The application includes a DSP processor with a noise blanker, AGC, and a variable-bandwidth CW filter, alongside an I/Q Recorder and player. It supports both 3 kHz radio passbands and wideband SDR receivers like SoftRock, RF Space SDR-IQ/SDR-14, SRL QuickSilver (QS1R), HPSDR Mercury, and Microtelecom Perseus. System requirements specify Windows XP/7/8/10 (32-bit or 64-bit), a Pentium-4 2.5 GHz for wideband operation or 1 GHz for 3-kHz radios, a COM port for CAT control, and a stereo sound card supporting 48 kHz sampling. It integrates with Elecraft KX3, Icom IC-7300/IC-7610, and Flex 6000 series radios, with documentation available for various setup configurations.

D-RATS is a small application designed to provide data communication capabilities with D-STAR radios. It supports text chatting, file transfers, position reporting and mapping, and much more! It is written in Python using GTK to run on multiple platforms.

Freeware real time DSP filter particularly for applications of amateur radios , IIR, FIR filter, low-pass, high-pass, band-pass filter, band suppressor (notch filter) individually adjustable

Argo, developed by I2PHD and IK2CZL, functions as a specialized freeware viewer for various weak signal modes, specifically MTHELL, Slow CW, QRSS, and DFCW. It processes audio input to visualize and decode these extremely low-speed transmissions, which are often imperceptible to the human ear. The software's capabilities extend to EME (Earth-Moon-Earth) operations, where its sensitivity to weak signals is particularly advantageous for detecting faint lunar reflections. The application provides a visual representation of the received signals, allowing operators to discern patterns and decode information from signals buried deep within the noise floor. Its design focuses on extracting data from signals with very narrow bandwidths and long integration times, characteristic of QRSS and similar modes. This tool is distinctively useful for experimenters and DXers engaged in challenging weak signal communication, offering a dedicated platform for modes not typically supported by general-purpose digital mode software. Its specialized focus on _Slow CW_ and _MTHELL_ makes it a niche but effective utility for specific operating scenarios.

Yahoo! group FT897. This group is dedicated to the discussion, operation, and application of the Yaesu FT-897 FT-897D amateur radios.

Signals Analyzer it's a a program, which is designed for the very qualitative analysis of different signals. The one of main fields of SA application is the analysis of unknown or unclear, strange signals. This programm will be very usefull to everyone from professional analysts to amateurs.

HotPaw MorseDecoder, an iOS application, provides real-time translation of Morse Code audio signals into plain text, leveraging the device's microphone or headset input. It incorporates a DSP narrow-band audio filter, adjustable from 300 to 2400 Hz, to mitigate background noise and QRM, enhancing signal clarity for decoding. The application offers both an automatic decoding mode and manual controls for fine-tuning parameters such as audio filter frequency, WPM dot/dash speed, noise threshold, and Farnsworth timing. The WPM detection automatically adapts from 8 to 40 WPM, with a QRQ High Speed mode extending this range to 30-80 WPM for faster code. A built-in spectrogram aids in identifying the precise audio frequency of the CW tones. User feedback indicates effective performance with various transceivers like the Yaesu FT-857 and Icom IC-R8600, particularly when manual settings are optimized. The app's ability to visually tune stations within the passband and decode speeds beyond an operator's manual capability has proven beneficial during contests and general QRP operation.

This resource catalogs a significant collection of historical military radio equipment, detailing various sets from World War II and the Cold War eras. It presents information on British, German, Japanese, USA, and other nations' wireless apparatus, including specific models like the _WS-19_, R1155, and WS-18, alongside clandestine spy equipment. The content covers the preservation and restoration of these historical items, with research results published on the site. The site provides dedicated sections for different national origins of equipment, such as "British sets," "German sets," and "North American sets," allowing for focused exploration of specific military communication technologies. It also features specialized pages on topics like the _Enigma machine_, PARASET builds, and historical events such as Arnhem and D-Day, contextualizing the use of these radios in significant military operations. The collection includes detailed descriptions and images of transmitters, receivers, and associated gear. The museum, located in Kidderminster, Worcs, U.K., organizes physical exhibitions and actively seeks new equipment for its collection, emphasizing its role in preserving military radio history.

Linux-based amateur radio logging software, _CQRLOG_, integrates a Firebird database for robust data management and offers radio control via _Hamlib_ libraries. It provides essential features for DXers and contesters, including DX cluster connectivity, _QRZ_ callbook lookup, a grayline map, and support for the ON6DP QSL manager database. The application incorporates a country resolution algorithm, developed by OK1RR, which is noted for its accuracy in identifying DX entities. The software's design prioritizes operational ease and maintenance, making it suitable for active logging. Its country resolution algorithm, based on meticulously maintained country tables, aims to minimize errors in DXCC credit. The integration of _Hamlib_ ensures compatibility with a wide array of transceivers, simplifying rig control for various operating modes and contest scenarios.

D-PRS converts these position reports from remote D-STAR radios to an APRS format. Windows .net application

Illustrates the construction of a compact _Moxon_ beam antenna specifically tailored for the 40-meter band (7 MHz). The resource details a homebrew project by W7XA, emphasizing its design for limited space while maintaining good bandwidth and directivity characteristics. It highlights the practical application of the _Moxon_ rectangle model to achieve performance on a lower HF band. The primary content is a downloadable PDF document titled "40-Meter-Mini-MOXON-Beam-Antenna.pdf," which provides comprehensive illustrations and technical specifications for replicating the antenna. This includes dimensions, materials, and assembly instructions, making it a practical guide for radio amateurs interested in directional antennas for HF. The project demonstrates how a relatively small footprint can yield a directional antenna suitable for DXing or contesting on 40 meters, a band typically requiring much larger arrays for similar gain and front-to-back ratios. The documentation supports hands-on construction.

One specific challenge in the KazShack, operating Single Operator Two Radios (SO2R), involved sharing a K9AY receive antenna between two transceivers without direct RF connection or manual feedline swapping. The solution, detailed in this project, adapts the **W3LPL RX bandpass filter** design to split 160m and 80m signals, feeding them to separate radio inputs while maintaining isolation. This approach also addresses the issue of strong broadcast band interference from a nearby 50KW WPTF transmitter on 680kc. The construction utilizes T-50-3 toroids and NP0 ceramic capacitors, built in a "dead bug" style on copper clad board. Each band's filter coils are identical and resonated to the desired frequency using an MFJ-259 antenna analyzer. A single DPDT relay, controlled by a remote toggle switch mounted on an aluminum panel, facilitates quick band switching between radios, simplifying low-band operations. While some signal loss is noted, the expected lower noise levels from the receive antenna are anticipated to compensate, potentially reducing the need for constant volume adjustments during toggling between transmit and receive antennas.

The **HFRadioSales.au** resource provides a commercial outlet for amateur and commercial radio operators seeking HF SSB equipment and related services. It focuses on the Australian market, offering new and refurbished transceivers, antennas, tuners, and a wide array of spare parts for brands like Codan, Barrett, and Qmac. The site details its role as a licensed dealer for new Barrett Communications and Codan radio and antenna systems, including specific models such as the Barrett 4050, 2050, and 950, and Codan Envoy and NGT series. This platform supports various applications, including vehicle, 4WD, outback, marine, and base station setups, catering to networks like HF Radio Club, VKS737, and RFDS. It also features commercial-grade antennas from Bushcomm, such as the BBA100C and SWC100, available for fast shipping from their Queensland warehouse. The site includes an FAQ section with general information on mobile HF communications in Australia and timelines for specific transceiver models.

It is a application which can be used for troubleshooting CB radio faults, by giving a graphical display of the normal operating frequencies generated by various parts of the CB radios circuits, it can help you identify if a frequency is incorrect or even missing. Another good use for this software is simulating possible frequency expansions, as it allows you to choose any frequency that the PLL is capable of generating, so you can see what the radio will allow you to get !

Radio mods for GE Phoenix radios to use in APRS applications

DX Buddy is a multi purpose ham radio application that let you control your radios, or controller, offer a logbook, cluster access, qrz lookups, and interface with several popular ham radio applications

Develops and manufactures radios and telecommunication devices for special applications. SDR Receivers, Digital HF transmitters, Digital SSB Exciter.

Packet-Radio-Controller for amateur radio, CB and commercial applications. Data radios (transceivers), receivers and transmitters for high speed data communication Assemblies for satellite ground stations, special receivers and transmitters.

Antique Radios of all kinds plus an operating ham station

Otto engineering is comprised of two divisions otto controls and otto communications. otto controls designs and manufactures a full line of switches and grips used in heavy equipment, aerospace, marine, medical and other demanding applications. otto communications designs and manufactures audio accessories for two-way radios used in public safety, police, fire, retail, hospitality manufacturing and other markets.

The resource, initially identified as "Alabama Radio," a dealer of amateur radios, antennas, CB equipment, scanners, and power supplies in Eastern Alabama, now redirects to a domain brokerage service. The original intent was to provide a commercial outlet for Ham Radio operators and CB enthusiasts seeking new equipment and accessories. This would have included transceivers, antenna systems, and various station components. However, the current content at the URL is _Startup Domains_, a platform for buying and selling premium .COM domain names. This shift means the resource no longer serves the amateur radio community directly. Instead, it focuses on digital asset transactions, with no mention of radio equipment, _DXing_, or _contesting_ activities. The original description of a regional radio dealer is no longer applicable to the live content.

Examines the Icom IC-2100H 2-meter mobile transceiver, detailing its operational characteristics and user experience. The review highlights the clear, easy-to-read display with internal labels, the button-filled microphone's functionality, and the rig's physical construction, including its weighty heat-sink and lack of a cooling fan. It also discusses memory programming, the unique amber-to-green backlight color options, and the radio's performance against _intermodulation_ in urban environments, noting it performs "pretty darn good" compared to other rigs. The analysis delves into a significant low-voltage cutoff problem, where the microphone ceases to function below approximately **12.6 VDC**, rendering the radio receive-only or causing it to stick in transmit. The author describes testing the voltage cutoff, observing it fluctuate from _12.38 VDC_ to 12.69 VDC. An update from Icom involved a "factory update" to the CPU's control code, which is strongly recommended for early-serial number units to prevent operational failure in low-power emergency scenarios.

The Receiver Test Data resource is a detailed review database focusing on the performance metrics of various radio receivers. The methodology involves rigorous lab measurements, often adhering to standards such as the ARRL RMDR (Reciprocal Mixing Dynamic Range) and BDR (Blocking Dynamic Range). Specific test equipment and protocols are utilized to assess parameters like noise floor (dBm), AGC threshold (uV), and LO noise (dBc/Hz). For example, the _Icom IC-7300_ is evaluated with a noise floor of **-133 dBm** and an LO noise of **-141 dBc/Hz**, providing insights into its performance under different operational conditions. The resource includes a wide range of models, from the _Elecraft K3S_ to the _Yaesu FTdx-101D_, each tested for dynamic range, sensitivity, and selectivity. The data is sorted by key metrics such as third-order dynamic range and phase noise limitations, with RMDR values calculated by subtracting 27 dB from LO noise figures. This structured approach allows users to compare different receivers' capabilities, focusing on technical specifications and performance outcomes in various scenarios. DXZone Focus: Review Database | Lab Measurements | -133 dBm | ARRL RMDR

The EACW Club, a Spanish amateur radio organization, focuses primarily on the promotion and practice of _Morse code_ (CW) within the amateur community. Members engage in various CW-centric activities, including contests and on-air events, fostering skill development and camaraderie among CW operators. The club provides a platform for hams to connect, exchange knowledge, and participate in specialized CW operations, contributing to the preservation and advancement of this fundamental mode. Operating as a specialized club, EACW supports its members in achieving proficiency in CW communication. Its initiatives often include educational resources and opportunities for practical application, such as CW nets and QRP operations. The club's emphasis on CW helps maintain a vibrant community for operators who value the efficiency and challenge of this mode, particularly in DXing and contesting scenarios. EACW Club activities contribute to a collective **150+** annual CW QSOs logged by its members, reflecting active participation and a strong commitment to the mode. The club also organizes an annual CW sprint, attracting participants from across Europe, with typical participation exceeding **50** unique callsigns.

The decibel (dB) is a logarithmic unit used to measure sound level, widely applied in electronics, signals, and communication to describe power, sound pressure, voltage, or intensity ratios. For instance, a 3 dB increase signifies a doubling of power, while a 10 dB increase represents a tenfold power multiplication. Sound pressure level is calculated as 20 log (p2/p1) dB, reflecting the square relationship between power and pressure. Standard reference levels, such as 20 micropascals for sound pressure in air, establish absolute dB values, where 0 dB corresponds to the reference level, not an absence of sound. Human hearing sensitivity varies with frequency, necessitating A and C weighting filters (dBA, dBC) in sound meters to approximate the ear's response. The phon unit relates to dB via psychophysically measured frequency response, with 1 kHz readings being identical. The sone unit quantifies perceived loudness, where 1 sone equals 40 phons, and a 10 dB increase above 40 phons roughly doubles perceived loudness. In radio, dBi measures antenna gain relative to an isotropic radiator, crucial for anisotropic radiation patterns.

Benelec Pty Ltd specializes in the design and manufacturing of **antennas** and RF components, covering a broad frequency range from 0.002 GHz to 8 GHz. Their product line includes Land Mobile Radio Antennas, such as HF 2-30MHz, VHF 40-180MHz, and UHF 200-520MHz models, alongside specialized Military Antennas for dismounted, UxS, C2, and EW applications. The company also produces Cellular Antennas, including 4G/5G and GPS/GNSS types, and Marine Antennas for both vessel-mounted and fixed-site installations. Additionally, Benelec offers a comprehensive range of coaxial cables, connectors like N-Type and SMA, and various radio accessories. The company's offerings extend to RF components such as duplexers, diplexers, and 50 Ohm loads, as well as DAS components like directional couplers and hybrid combiners. Benelec provides EMP and lightning protection solutions, including 1/4 Wave Stub protectors and replaceable GAS capsules. Their product catalog also features P25, DMR, and FM Analog radios, along with portable and mobile radio accessories like batteries, chargers, and cabled headsets. The company supports various sectors with robust communication solutions.

This resource, originally intended to detail the technical specifications of the **Clover** digital communications mode, currently presents a "Page not found" error. The _Clover_ mode was designed for conveying 8-bit digital data over narrow-band high-frequency radio channels, offering robust performance under challenging propagation conditions. Its design focused on efficient data transfer and error correction, making it suitable for amateur radio operators seeking reliable digital links. The absence of the page prevents analysis of specific technical parameters, such as modulation schemes, data rates, or error correction codes that would have been presented. Historically, Clover offered significant advantages in throughput and reliability compared to earlier digital modes over HF, often achieving higher effective data rates than modes like PACTOR or AMTOR under similar signal-to-noise ratios. Without the content, a direct comparison of its performance metrics or practical application scenarios is not possible.

PZTLog is a freeware amateur radio logging application designed for Windows operating systems, facilitating rapid **QSO entry** and management. It integrates features such as DXCC statistics tracking, a built-in DX Cluster client, and support for various digital modes including PSK31, PSK63, PSK125, and RTTY. The software provides a straightforward interface for inputting essential contact details and supports real-time interaction with DX spotting networks, enhancing the operator's situational awareness during operating sessions. The application's utility extends to contest logging, offering a streamlined approach for competitive operating. PZTLog's capability to manage **DXCC awards** and integrate with digital mode operations positions it as a versatile tool for general logging and specific contest scenarios. Its design prioritizes ease of use for quick data entry, making it suitable for operators who require efficient logging without extensive configuration.

Approximately 190–209 words of content are available, including previously unreleased **radio intercepts** from the Russian army during the Battle for Kyiv, with confirmed authenticity. The platform provides extensive news coverage, video reports, and analytical content focusing on Ukraine and international affairs, frequently publishing exclusive materials. Recent articles cover topics such as emergency power outages in Kyiv, discussions on Iran's nuclear program, and Belgium's policy regarding temporary protection for children born after Russia's full-scale invasion. The site also features in-depth investigations into Russian military losses, the political isolation of Hungary within the EU, and mental health advice for coping with wartime stress. Timely updates are provided throughout the day, detailing events such as drone incidents in Lithuania and proposed restrictions on military personnel's access to gambling in Ukraine. The platform offers a variety of multimedia content, including video and photo reports on events like the double explosion in Bucha and search operations for victims of the Volyn tragedy. Editorial selections delve into topics such as parliamentary elections in Slovenia, internal political conflicts in Ukraine, and the export of Ukrainian drones to the Middle East, alongside historical analyses and opinion pieces from various contributors, often featuring expert commentary and reader engagement. The content is primarily focused on current events and geopolitical analysis, with a strong emphasis on the **Ukrainian conflict**.

iOS EchoLink client, this free app will allow licenced ham radio operators to use iPhone, iPad or iPod devices to connect to the echoLink system and connect to repeaters or other echolink users.

The Japan Amateur Radio League (JARL) outlines the application process for foreign amateur radio operators seeking to establish a station in Japan. Required documentation includes a completed JARL-96-04 station information form, a signed JARL-04-09A Letter of Authorization, photocopies of the current amateur radio operator certificate, passport or Residence Card, and proof of bank transfer or PayPal payment. Applications must be submitted at least 60 days prior to the desired operation start date to the JARL International Section in Tokyo. Licensing information specifies eligibility for those with valid amateur qualifications listed in Annex 1, regardless of nationality. A portable/mobile 50W station license is recommended for nationwide operation, costing JPY 2,750. Fixed station licenses for output power exceeding 50W but not more than 200W cost JPY 5,400. Licenses are granted for the authorized stay period, up to five years, and are renewable for JPY 1,700. Operations exceeding 200W require a different procedure involving direct submission to the Ministry of Internal Affairs and Communications (MIC) and an on-site inspection. Radios without a 'Technical Standard Certification Number' require assurance by JARD, incurring a JPY 5,500 fee for the first radio and JPY 1,100 for each additional unit. Payment options include bank transfer to MUFG Bank, Ltd., Komagome Branch, or PayPal. The document also details guest operation rules, allowing validly licensed foreign amateurs to operate local stations under specific conditions, including host presence and identification with the host's callsign followed by their own.

QRZ.com Free app for iPhone iPad let you search the QRZ.COM call sign database from your mobile device. Completely free with no subscription required.

The _Sci.Electronics FAQ: Repair: RFI/EMI Info_ document, authored by Daniel 9V1ZV, provides a detailed analysis of computer-generated RFI/EMI, focusing on its impact on radio reception. It identifies common RFI sources such as CPU clock rates (e.g., 4.77 MHz to 80 MHz), video card oscillators (e.g., 14.316 MHz), and even keyboard microprocessors, all of which generate square-wave harmonics across HF and L-VHF regions. The resource outlines a systematic procedure for pinpointing RFI origins, including disconnecting peripherals and using a portable AM/SW receiver with a ferrite rod antenna to localize strong interference sources. The document categorizes RFI mitigation into shielding, filtering, and design problems, offering practical solutions for each. It recommends applying conductive sprays like _EMI-LAC_ or _EMV-LACK_ to plastic casings of radios, monitors, and CPUs to create effective Faraday cages, emphasizing proper grounding and avoiding short circuits. For filtering, the guide suggests using line filters, ferrite beads, and toroids on power and data lines, and small value capacitors (e.g., 0.01 uF for serial/parallel, 100 pF for video) to shunt RFI to ground. It also discusses the use of bandpass, high-pass, low-pass, and notch filters on the receiver front-end or antenna feed to combat specific in-band noise.

Demonstrates the _RoMac Automatic CW Identifier 2012_ software, a Windows application designed to automate station identification and provide a tuning pulser. It can send CW identification via a sound card's audio output or by keying a radio's manual CW jack using a serial port's DTR line. The software also supports CAT commands for various Kenwood, Yaesu, Flex, and Elecraft radios, enabling automatic mode and frequency changes for ID transmission. It integrates with USB audio-capable radios like the Icom 7300 and Yaesu FT-991, simplifying connectivity with a single USB cable. The application features a fully programmable interface, adjustable CW speed from **5 to 35 WPM**, and ID intervals from **5 to 30 minutes**. The integrated "Pulse Tuner" function allows for safe amplifier and antenna tuner adjustments by sending short audio tones or rapid CW keying, with an adjustable duty cycle from 1% to 100%. It offers compatibility with a wide range of transceivers and amplifiers, and a schematic for a basic sound card interface is included for users without existing setups.

The 7-minute, 52-second video, published on December 31, 2016, by TheStingyHam, details several methods for optimizing receive audio on the **Elecraft KX2** QRP transceiver. It specifically addresses challenges encountered on the 40-meter band, a common haunt for QRP operators, while also noting that 15m and 20m operations might benefit from different settings, such as combining the preamp with receive EQ and RF gain adjustments. Key moments highlighted in the video include specific adjustments for noise reduction, filter settings, signal attenuation, and receive equalization. These techniques are demonstrated to help operators extract clearer signals from a noisy band, a critical skill for successful portable operations and DXing with low power. The author, drawing from field experience, suggests that while the tips are primarily aimed at 40m, the underlying principles of careful audio and RF gain management are broadly applicable across the HF spectrum, enhancing the overall QRP operating experience.

Facilitates logging of amateur radio contacts directly within a web browser, enabling seamless operation across various devices including Windows, macOS, Linux, iOS, and Android. This web-based application stores all log data securely in the cloud, providing accessibility from any internet-connected location. It supports importing existing log data via CSV files, with future plans for _ADIF_ file import, and offers a robust QSL card generation feature, producing print-ready PDF files in standard 148mm x 100mm dimensions. The platform integrates with Japanese government databases to automatically populate callsign-related information such as station location and license issue dates, streamlining data entry. It also assists with JCC/JCG searches for accurate QTH logging. The service leverages SSL encryption for all communications and benefits from security oversight by certified information security professionals. Users can register using email/password or existing Facebook/Google accounts, and the beta version is currently available for free. The system has processed over **5,297,881** logs, with **28,369** logs recorded in the past 24 hours.

1.5 dB of matched line loss can be calculated for a given transmission line using this online tool, which employs a model calibrated from empirical data. The calculator allows radio amateurs to input specific transmission line types, such as _RG-8_ or _RG-58_, and then determine the expected signal attenuation. This is crucial for optimizing antenna system efficiency and understanding power delivery to the radiating element, especially for HF and VHF operations where feedline losses can significantly impact performance. Beyond matched loss, the calculator also provides an estimate for mismatched loss if the Standing Wave Ratio (SWR) is specified. This feature helps operators quantify the additional power loss due to impedance discontinuities between the transceiver, feedline, and antenna, which is a common concern in amateur radio installations. Accurate loss calculations are vital for effective station design and for predicting actual radiated power. The tool's utility extends to various operating scenarios, from fixed station setups to portable deployments, aiding in the selection of appropriate feedline lengths and types to minimize signal degradation. Understanding these losses is a fundamental aspect of maximizing the effectiveness of any amateur radio antenna system.

CATSync V1.30 integrates OpenWebRX support, expanding its capability to synchronize a local amateur radio transceiver's CAT control with a broader range of public WebSDR receivers. The software facilitates real-time frequency tracking, allowing the operator to adjust their physical rig's VFO and observe the connected WebSDR instantly follow the tuned frequency. This functionality is crucial for remote listening, signal comparison, and verifying propagation conditions across different geographic locations using a familiar hardware interface. The application supports both the classical WebSDR interface and KiwiSDR platforms, providing a consistent control experience across various online SDR deployments. It bridges the gap between local station operation and the vast network of globally distributed software-defined radios, offering a practical tool for DXers and contesters. CATSync is designed for Windows and Linux environments, with Android compatibility noted, making it accessible to a wide user base seeking to leverage WebSDR resources with their existing station setup.

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.

CCAE Software Log provides a dedicated platform for amateur radio operators to manage their QSO records, offering functionalities beyond basic logging. This application supports various operational aspects, including contest participation and general DXing activities, catering to the needs of radio enthusiasts who utilize classic equipment such as Collins radios. The software integrates features for efficient data entry and retrieval, allowing users to maintain a detailed history of their contacts. It is designed to be intuitive for operators focused on collecting and preserving their radio communication logs. The program's development by the European Collins Collector Association (F6HOY) suggests a focus on reliability and specific utility for vintage radio enthusiasts. Its core function is to serve as a robust **logbook software**, facilitating organized record-keeping for ham radio operations.

Antenna Authority Inc. offers a wide assortment of directional, wideband antennas and other equipment specifically engineered for radio direction finding (DFing) and geolocation applications. Their product line includes _log periodic_, _cavity-backed spirals_, and _Yagi_ antennas, alongside covert antenna solutions for various operational requirements. The company emphasizes its expertise in designing and manufacturing specialized antennas for both overt and covert operations. Beyond standard offerings, Antenna Authority Inc. provides custom design services to meet specific client needs, focusing on tailored RF directional products. Their capabilities extend to developing antennas for vehicles and optimizing their operational performance in diverse scenarios. The firm is located at 3381 W. County Line Road, Douglasville, Ga. 30135-1145. Ferrel Bentley is associated with Antenna Authority Inc., which has been operating since at least 2005, as indicated by the copyright notice.

Official aprs.fi iOS app, immediate real-time visibility to APRS traffic near you and around the world.