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After owning the second-hand radio for a few months, it developed a sense wire failure, limiting output to 20 watts. Yaesu support advised the owner, an Electrical Engineer, to investigate. The issue was traced to a blown digital transistor, Q1032. Yaesu provided free replacements, revealing intricate internal components during the repair.

KISS703 is a 703 Hz narrowband digital mode for amateur radio, designed for simple, low-power operation without computers. A 500 Hz pilot tone ensures frequency alignment, replaced by unique tones for 37 symbols (letters, numbers, space). Built from common discrete components, it draws about 40 mA at 12 V, ideal for SOTA/IOTA use. The receiver uses amplification, wave shaping, and a pulse-counting frequency meter for manual decoding via a calibrated meter. Transmitter and receiver calibration involves marking meter positions for each tone, enabling fully self-contained messaging with minimal hardware in portable or fixed operations.

This excel workbook addresses the issue of power loss in transmission lines with complex characteristic impedance ZoZo​. It illustrates the discrepancy between actual loss (0.35 dB) and matched line loss (0.6 dB) using a simplified example, highlighting potential software tool limitations. The RF Feedline Power-Loss Calculator provides accurate end-to-end loss assessments for both microwave and RF applications. This tool is suitable for engineers and students and is compatible with Windows versions of Excel 2016 or later, though it is not compatible with Macintosh systems.

The article "Icom IC7300 RTC Fix" details the meticulous repair of an Icom IC-7300's faulty real-time clock (RTC). The author and a friend, Nacho, discovered the RTC was gaining an unacceptable 11 seconds per day. Investigations revealed the Seiko Epson RX8803LC RTC was far outside its specified stability. Despite replacing the RTC and a burned pullup resistor, the transceiver still malfunctioned, leading to the replacement of the processor. Post-repair, the clock's accuracy improved significantly, now gaining only 1.4 seconds per month. This narrative underscores the complexities of electronic repairs and the satisfaction of resolving intricate issues.

The author fixed a friend's Kenwood TS-850S radio, which suffered from Capacitor Plague, a common problem in 1990s electronics where capacitors leak and damage circuit boards. The CAR board, responsible for generating signals, was especially affected. The author cleaned the board, replaced the capacitors, and repaired a broken trace. Although the radio mostly functioned afterward, the "Slope Tune" control behaved abnormally. The cause seems to be a software issue, not a hardware one.

Single Sideband (SSB) operation requires careful attention to the relationship between a radio's displayed frequency (suppressed carrier) and the actual 3 kHz wide audio signal. This resource clarifies how Upper Sideband (USB) and Lower Sideband (LSB) signals occupy spectrum above or below the indicated frequency, respectively. It provides practical examples for General Class operators on the **20m** and **40m** bands, such as setting a VFO to 14.226 MHz for USB on 20m or 7.178 MHz for LSB on 40m, to maintain a safe margin from band edges. The resource emphasizes the critical importance of staying within allocated band limits to prevent out-of-band emissions, particularly when operating close to band edges. It includes relevant excerpts from **FCC Regulation Part 97**, specifically section 97.307, which details emission standards, necessary bandwidth, and spurious emission attenuation requirements. The text explains that unused sidebands are considered spurious emissions and notes that modern HF equipment typically exceeds the 43 dB spurious emission reduction standard, often achieving 60 dB or more.

This report details a modification of a Diamond V2000 antenna, replacing its original two 0.50 m radials with two 1.55 m radials. Initial M5-threaded rods failed to fit; the housing required M6 threads. Custom radials were made using 8 mm OD aluminium tubing and M6-threaded stainless steel ends, secured with nuts machined to 9 mm. SWR issues on 6 m (>2:1) were largely due to a poor counterpoise connection, resolved during reassembly. NanoVNA measurements showed no adverse effects on 2 m or 70 cm. The final setup retains the two 1.55 m radials and original counterpoise. Other operators reported SWR degradation with similar mods—sometimes fixed by adding capacitance—but this was not observed here.

The resource details HF time broadcast stations, categorizing them into "Standard Frequency & Time Signal Broadcast" and "Time Signal Broadcast" types. Standard Frequency & Time Signal Broadcasts, like those on **2.5 MHz** and **5 MHz**, originate from official time observatories and offer continuous standard frequencies, time signals, and often voice announcements, potentially including meteorological data. These stations operate in the SW band. Time Signal Broadcasts also provide continuous time signals, typically with voice announcements, but without the strict observatory origin requirement. The list includes specific frequencies such as 3.33 MHz, 4.996 MHz, 7.85 MHz, 9.996 MHz, 14.67 MHz, 14.996 MHz, 15.006 MHz, and 20 MHz, alongside the primary standard frequencies. Each entry specifies the station's ID time, call sign, geographic coordinates, and operational notes, including languages like _English_, Chinese, Portuguese, Korean, and Spanish. Some entries also indicate decommissioning dates, such as the station on 3.33 MHz scheduled for 2026-06-22.

This thoughtful review details ajourney from the stock Elecraft KXPD2 paddle to an innovative pressure-sensor alternative. The author candidly describes issues with their original paddle—intermittent operation and loosening screws—before discovering VK3IL's pressure-sensitive design through QST magazine. The construction process, using a PCB and components generously shared by the designer, proved straightforward despite challenging SMD soldering. What stands out is the clever DIY housing solution: a "sandwich" of closed-cell foam encased in heat-shrink tubing that fits comfortably in hand. The ergonomic design allows effective single-handed operation for portable SOTA activations. The successful implementation has rendered the original paddle obsolete, leaving only the task of covering the radio's paddle port.

This comprehensive article dispels common misconceptions about Standing Wave Ratio (SWR) in amateur radio. The author explains that SWR is not an antenna property but a measure of the entire antenna system, representing the mismatch between transmission line and load impedance. Contrary to popular belief, modest SWR values (under 3:1) typically cause minimal power loss in HF applications. The article demonstrates mathematically why obsession with achieving 1:1 SWR is often unnecessary, explains when SWR matters more (QRO, QRP, VHF/UHF), and explores effective matching techniques including proper ATU placement and quarter-wavelength transformers.

YaesuFT1000MK V stands out with improved close-spaced SSB transmit performance, reversing a trend seen in other modern radios. Featuring a class-A mode, it offers clean HV finals when kept out of ALC. However, two significant flaws persist: the noise blanker causes receiver IM distortion, and the transmitter lacks wave-shaping on CW, resulting in pronounced keyclicks. Preliminary tests reveal strong keyclicks +1kHz and -1kHz, prompting a combined modification to address both issues.

This is a contest keyer for the AEA MM-3 Morse Machine. It integrates with OmniRig for your radio's frequency. It has a built in logbook as well as a keyboard keyer. You can also export your log as an .adi or cabrillo format for contest submission. Please find my contact details on QRZ.COM for any suggestions or help 73 ZS6WAR

Our primary mission is to provide backup and secondary communications to our served agencies when needed. We also provide general volunteer and manpower services to the community. Geauga County OH

VE1ZAC's analysis details the performance of **MFJ927** and **SGC239** autotuners with portable HF vertical antennas, specifically comparing 31 ft and 43 ft configurations. The resource originated from challenges encountered during a Maritime QSO Party roving operation, necessitating a lightweight and easily deployable antenna system. Target bands for the contest included 80, 40, 20, 15, and 10 meters, with a maximum power handling of 100 W CW. The author utilized a 30-foot carbon fiber push-up pole to support a vertical wire element, noting its 2 lb weight and reliability. EZNEC modeling was employed to predict performance, showing favorable results for a 30-foot vertical with elevated radials, particularly on 40 and 20 meters. Feedpoint impedance measurements, taken with an AIM4170C, are presented for various HF bands, both with and without a 41-foot RG6 stub designed to reduce reactance on 80 and 20 meters. The stub significantly improved matching on these bands, easing the tuner's workload. Operational tests revealed issues with the MFJ927's reliability during contest setup, leading to reliance on the K3's internal tuner. The SGC239, tested post-contest, performed flawlessly. A detailed side-by-side comparison covers mechanical aspects, connection options, power bias, impedance range, board quality, and documentation. Modifications to the MFJ927, including a new aluminum case, white paint for heat reduction, and upgraded impedance-measuring resistors, are also described.

The article discusses the construction of a UHF band-stop stub filter to protect an APRS receiver from potential damage during a balloon launch. The author, who communicates using a 441 MHz transmitter, needed to ensure that the RTL-SDR dongle receiving at 144 MHz wouldn't be damaged by the transmissions. The solution involved creating a quarter-wavelength open stub filter using coaxial cable, which attenuates the 441 MHz signal while allowing the 144 MHz signal to pass through. The filter's design is based on the principles of constructive and destructive interference, with careful measurement and trimming to achieve the desired frequency response. The final filter provided 34.8 dB of insertion loss at 441 MHz and minimal loss at 144 MHz, effectively protecting the receiver.

This page by ARCTICPEAK provides a calculator for determining ERP and EIRP (Effective radiated power and effective isotropic radiated power). The tool is designed to help hams calculate and understand the power radiated by their radio equipment. The content is useful for ham radio operators who want to optimize their transmission power and comply with regulations. LA8OKA Martin has created this resource to assist hams in accurately measuring their radio signals.

Twenty 1-watt carbon film resistors are configured in parallel to construct a 50-ohm **dummy load** for amateur radio applications. The design incorporates a heatsink for thermal dissipation and an **SO-239 connector** for RF input, making it suitable for QRP operations. This budget-friendly project details component selection, soldering techniques, and mounting procedures, achieving a continuous power rating of 10 watts and intermittent handling of up to 100 watts across HF and VHF frequency ranges. The resource provides a step-by-step guide for assembly. This construction offers an economical solution for essential shack tasks such as antenna tuning, transmitter testing, and SWR meter calibration without radiating an RF signal. The utilization of readily available components significantly reduces the overall build cost compared to commercial alternatives, providing radio amateurs with a functional and reliable test accessory. While specific VSWR measurements are not provided, the design prioritizes practical utility for low-power transceiver diagnostics and general RF experimentation.

The _Colorado QSO Party_ is scheduled for **September 12, 2026**. This amateur radio event focuses on contacts with stations operating within Colorado. The _Grand Mesa Contesters of Colorado_ sponsors the event. Operators may pursue contacts across all **64 counties** of Colorado. Activations for programs such as POTA and SOTA are permissible during the event period. Logs generated from these activations are eligible for submission to both the _Colorado QSO Party_ and the associated operating program. DXZone Focus: QSO Party | Colorado | Mixed | All Amateur Bands

Examines the historical context of amateur radio, specifically focusing on Guglielmo Marconi's pioneering wireless transatlantic signal reception at Signal Hill, Newfoundland, in 1901. It describes the operation of a contemporary remote radio station at Signal Hill, utilizing the special event call sign _VD1M_ issued by Innovation, Science and Economic Development Canada. The content recounts a specific contact from Signal Hill, reporting a signal strength of 5 by 9 to a station in Sarnia, Ontario, which received the signal at 3 by 3. The narrative also introduces the concept of 'Marconi chasers' who endeavor to replicate historical transmission methods. Further, the resource discusses general amateur radio operating procedures, the evolution of the hobby, and its critical role in emergency communications, citing examples from hurricanes _Irma_ and _Maria_ in 2017 and the conflict in Ukraine in 2022.

This document provides a comprehensive guide on renewing an US amateur radio license through the Federal Communications Commission (FCC) using the new COmmission REgistration System (CORES). Published on QST October 23, it outlines the necessary steps for creating a CORES account, associating it with a Federal Registration Number (FRN), and completing the renewal application. Key points include the requirement of a $35 fee for the renewal process, which must be paid online after the application is submitted. The guide emphasizes the importance of logging into the FCC License Manager system during the renewal window and provides instructions on how to navigate the renewal process, including obtaining confirmation and access to the renewed license. Additionally, it offers contact information for FCC support and links to further resources for assistance.

Testing IdeeTron Lorank8 for LoRaWAN with ham radio transmissions. Assessing compatibility, interference, and planning permanent setup. Follow the experimentation and integration into the Almelo Community page

The **5-Port 12 Volt DC Power Strip Kit (Rev 4)** offers a practical solution for managing shack power distribution, providing one input and five fused outputs. All connections utilize the ubiquitous Anderson PowerPole connectors, a standard for many amateur radio operators, ensuring a clean, organized, and safe way to power multiple 12 VDC transceivers and accessories from a single source. This design mitigates the common issue of tangled wires and overloaded connections in a typical ham shack. Rated for a maximum current of 20 Amps at 12 VDC, the strip incorporates an integrated LED to indicate when external power is applied. Each output is individually fused, a critical safety feature that protects connected equipment from overcurrent conditions without affecting other devices on the strip. This level of protection is essential for preserving sensitive radio gear during operation. Assembly requires basic soldering skills and hand tools, with a high-power soldering iron and wide chisel tip specifically recommended for best results. The kit's compact dimensions of 4.13" x 1.78" allow for flexible mounting via screw holes, making it suitable for various shack configurations and portable operations.

Learn about the HAMTV Digital Amateur Television (DATV) transmitter on the International Space Station (ISS), transmitting video and audio in MPEG-2 format using the DVB-S protocol. Discover its history, installations, failures, and repairs, as well as the current status and live video feed. Explore the technical details and challenges of the HAMTV transmitter, including power output, polarization, and antenna location. Find recordings of previous transmissions and understand the potential signal reflections caused by various ISS components. Stay updated on the latest developments and activities related to HAMTV from the ISS.

After years of reliable performance, a 26-year-old Icom 706MK2G exhibited an unusual deviation during FM transmission, with the actual frequency being 10kHz off from the displayed frequency. Additionally, the power meter showed a sharp dip during transmission. Upon investigation, it was discovered that the FM VCO voltage adjust variable had become dirty and sluggish over time. By adjusting the variable capacitor and cleaning it with switch cleaner, the issue was resolved, restoring stable power output and accurate frequency transmission.

This page by Arctic Peak provides a detailed explanation on how to use quarter-wave transmission lines as impedance transformers in ham radio antenna work. It explains how to match impedance values by connecting them with a λ/4 transmission line. The page also offers guidance on constructing your own transmission lines with specific impedance requirements, along with a calculator to determine the quarter wave length based on velocity factor and frequency. Useful for hams looking to optimize antenna performance and match transmission line impedance effectively.

This page provides a detailed guide on the J-pole antenna, an end-fed half-wave antenna matched to the feedline by a quarter-wave transmission line stub. It covers the characteristics, construction materials, feeding options, and mounting considerations for optimal performance. The information is useful for hams or amateur radio operators looking to build and set up a J-pole antenna for improved transmission and reception.

Manufacturers of roof towers ideal solution for HOA restrictions, Limited lot space, 2nd or 3rd tower and perfect for satellite & ISS

Provides access to a robust DX cluster node, G6NHU-2, running DX Spider software, which facilitates real-time amateur radio contact spotting across HF bands. This service is engineered for high reliability and low latency, ensuring rapid dissemination of DX spots from a global network of interconnected nodes. It features multiple redundant links to prevent data loss and maintain continuous operation, even if individual connections drop. The cluster integrates directly with the Reverse Beacon Network (RBN), allowing users to enable or disable skimmer spots for specific modes like CW, RTTY, FT8, and FT4. It also offers an extensive one-year spot history, significantly longer than most other DX clusters, which typically retain only a month of data. The node supports various lookup commands for callsign information, beam headings, QSL routing, and FCC database lookups, enhancing operational efficiency for DXers and contesters. Additionally, it permits self-spotting, a feature increasingly relevant in modern contests, and provides detailed instructions for connecting popular logging software such as N1MM+, HamRadioDeluxe, MacLoggerDX, LOG4OM2, Logger32, and N3FJP's Amateur Contact Log.

The article details how to eliminate Radio Frequency Interference (RFI) from the Behringer HA400 headphone amplifier when used in ham radio setups. While the HA400 is praised for its quality and affordability, it was not designed for RF environments, causing distortion when used with a 500-watt radio station. Initial attempts using clamp-on ferrites on the headphone and power cables only partially resolved the issue. Upon opening the unit, the author discovered the circuit lacked RF bypassing components. The solution involved installing 0.1μF (104) capacitors at key points in the circuit: the power supply input, audio circuits, and op amp inputs. This modification, combined with the external ferrites, completely eliminated the RFI problem, making the unit suitable for ham radio operations.

The article describes ongoing issues with a new TS590s transceiver, including intermittent reception and transmission failures. After a repair diagnosed as a "Control Unit interruption," the problem persisted. The author discovered the cause was a poorly crimped CN601 connector on the Control Unit board, leading to signal loss when moved. Soldering the connector resolved the issue. Similar problems reported by other users suggest a potential defect in the cables, pointing to a possible manufacturing issue.

The 52 Week Ham Radio Challenge offers hams a year-long series of 52 challenges to test and improve their skills. Created by Fabian Kurz, DJ5CW, this project includes bonus challenges that can be substituted for missed or failed tasks. The challenges cover a range of topics and activities related to ham radio operation, providing a fun and educational way for hams to enhance their knowledge and expertise. Whether you are a beginner or an experienced operator, this challenge is designed to engage and motivate ham radio enthusiasts throughout the year.

The Gemini Amplifier Remote Control software operates on Windows 7 and above, facilitating remote management of the Gemini HF-1K and DX-1200 amplifiers. Users connect via Ethernet, configuring the amplifier's IP address through the front panel. The software allows seamless band and antenna selection, saving settings for each band without requiring transmission. Integration with _OmniRig_ from Afreet Software, Inc. enables automatic band adjustments based on the radio's frequency changes. Users can configure serial or virtual serial connections, with tracking options accessible through the ribbon bar. The software supports speech functionality, enhancing accessibility for operators. Firmware updates, such as version 2.5Ee, introduce features like background datalogging and power output control, uploaded via FTP. Version 1.2.0 allows users to offload internal parameter data for support purposes. The firmware upload process requires the amplifier's IP address and port 21, taking approximately 90 seconds. Users are encouraged to upgrade to the latest firmware for improved performance and remote diagnostics.

An Arduino-based interface provides a remote tuner call command for Icom **IC7700** and **IC7800** transceivers, addressing the lack of a built-in function for external tuners such as the MFJ 998RT. This setup initiates a low-power transmit signal, typically 15 watts, allowing the remote autotuner to perform its matching sequence. The article details the required CI-V line communication and modifications to existing Arduino code, specifically referencing contributions from Jean-Jacques ON7EQ for improved Icom interrogation routines. The system involves a sequence of steps: storing the transceiver's current mode and power, disabling the internal autotuner, activating a control relay to interrupt the amplifier line, switching to RTTY mode at low power, and initiating transmit. The transmit duration is manually controlled by the operator, observing the SWR meter until a low SWR is achieved, then a second button press stops the transmission. A built-in 4-second transmit limit provides a safety measure. After tuning, the routine restores the original mode and power settings, re-enables the internal autotuner, and performs a brief 2-second RTTY transmission for internal tuner adjustment. The circuit diagram includes a Panasonic form 2 relay for amp control and emphasizes critical delays in the Arduino code for stable operation at 9600 baud CI-V communication. Compatibility with logging software like DXLab, N1MM, and N3FJP is noted, with specific interrogation time settings required to avoid conflicts.

Cloudlog Helper addresses the need for streamlined, automated logging of amateur radio contacts, particularly for operators utilizing digital modes like FT8 or those with limited system resources. This utility syncs real-time rig data and QSO information to various logging platforms, including _Cloudlog_ and Wavelog, supporting mainstream transceivers. It integrates seamlessly with popular digital mode software such as JTDX and WSJT-X, ensuring that contact details are captured and uploaded without manual intervention. Operators can compile the software themselves and configure essential settings, including their Maidenhead locator, Cloudlog server address, API key, and station ID. The application's design prioritizes efficiency and portability, making it a practical solution for hams who prefer automated logging processes. While an unofficial community project, Cloudlog Helper provides a robust framework for automating the often-tedious task of logging, supporting multiple logging services beyond its primary integration. It offers a direct method for hams to maintain accurate and up-to-date logbooks with minimal effort, potentially improving their DXCC or other award tracking by ensuring no QSO is missed.

Tracing the foundational work of Guglielmo Marconi, this article details his early laboratory experiments in 1895, where he successfully transmitted wireless signals over 1.5 miles. It highlights his 1896 patent for a wireless telegraphy system in England and subsequent demonstrations, including signal transmissions up to 6.4 km (4 miles) on Salisbury Plain and nearly 14.5 km (9 miles) across the Bristol Channel. Marconi's work built upon the mathematical theories of _James Clerk Maxwell_ and the experimental results of _Heinrich Hertz_, proving the practical feasibility of radio communication. The resource further chronicles the formation of The Wireless Telegraph & Signal Company Limited in 1897 and Marconi's relentless efforts to popularize radiotelegraphy. A significant milestone was the 1901 transatlantic reception of the Morse code letter "S" from Poldhu, Cornwall, at St. John's, Newfoundland, using a kite-supported wire antenna, defying contemporary mathematical predictions about Earth's curvature limiting range. This achievement underscored the global potential of radio. The article also touches upon Marconi's later discoveries, such as the "daytime effect" concerning atmospheric reflection of radio waves, and his 1902 patent for a magnetic detector, which became a standard wireless receiver. His contributions earned him a Nobel Prize in 1909.

A website that provides information about CubeSats, including the CubeSats' mission, frequencies, and status.

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

Fram2, the first human spaceflight in polar orbit, launches spring 2025 aboard SpaceX's Falcon 9. Inspired by the polar exploration ship Fram, the mission highlights innovation and exploration. Four astronauts from Europe and Australia will orbit Earth for 3–5 days, including ham radio operator Rabea Rogge, who will transmit SSTV images for an educational competition. Open to students aged 16–25, the contest challenges teams to identify polar-related sites. Fram2 collaborates with ARISS to inspire STEAM learning through space communications.

This page provides a calculator to determine the total line loss and additional line loss in your transmission line based on the level of SWR. It helps hams understand the impact of high SWR on transmission line losses. The calculator allows users to input their SWR level and get accurate calculations of total losses. This tool is useful for ham radio operators looking to optimize their transmission setups and improve overall efficiency.

Enables digital radio transceivers to function as versatile data communication nodes, supporting applications like _Reticulum_ networking, messaging with Sideband, and acting as a LoRa-based KISS-compatible amateur radio TNC. This firmware transforms off-the-shelf development boards into powerful, long-range data radios, facilitating robust communication over significant distances, potentially achieving **hundreds of kilometers** with optimal setups. It supports a range of hardware, including unsigned.io's Handheld RNodes (v2.x and v1.x), LilyGO T-Beam v1.1, LilyGO LoRa32 (v2.0, v2.1), and Heltec LoRa32 v2 devices. Compatibility extends to transceiver modules utilizing Semtech SX1276, SX1278, SX1262, SX1268, and SX1280 chips, provided they have an SPI interface and exposed interrupt pins. Installation is streamlined via the `rnodeconf` utility, part of the `rns` package, simplifying the flashing process for users. The project operates under the GNU General Public License v3.0, promoting open development and user freedom. It encourages community involvement in building and deploying RNodes for various purposes, from personal communication to establishing resilient, decentralized networks. The firmware's design emphasizes flexibility, allowing for diverse configurations to suit specific operational requirements.

The project aims to create a remote control system for the VK5RSE beacons located near Millicent, South Australia. The beacons on 144.550, 432.550, and 1296.550 MHz can interfere with nearby amateur radio operations, particularly for EME work on 1296 MHz. The remote control system uses a DTMF decoder and PIC microcontroller to allow turning the beacons on and off individually or in combination. The system is housed in a diecast box and powered from 5-8V. The password-protected control allows authorized users to manage the beacon operations remotely, helping mitigate interference issues for local amateurs.

Early 20th-century transatlantic wireless communication efforts involved distinct technical approaches by Reginald Fessenden and Guglielmo Marconi. Marconi's systems, operational until approximately 1912, primarily utilized _spark technology_ for wireless telegraphy, facilitating Morse code communication between ships and across oceans. His Poldhu station in December 1901 radiated signals in the MF band around 850 kHz, later evolving to 272 kHz in October 1902, and eventually 45 kHz by late 1907 with increasingly larger antenna structures like the pyramidal monopole and capacitive top-loaded arrays. Fessenden, conversely, focused on _continuous wave transmission_ for wireless telephony, recognizing its necessity for speech. His transatlantic experiments in 1906 employed synchronous rotary-spark-gap transmitters and 420-foot umbrella top-loaded antennas at Brant Rock, MA, and Machrihanish, Scotland, tuned to approximately 80 kHz. Fessenden later utilized the _Alexanderson HF alternator_ at 75 kHz by late 1906 for pure CW transmission, integrating a carbon microphone for amplitude modulation. Receiver technology also differed, with Marconi initially relying on untuned coherer-type detectors, later developing the magnetic detector in 1902, while Fessenden's CW approach necessitated more advanced detection methods.

This study analyzes the antenna pattern of the Utah Amateur Radio Club's 146.760 MHz repeater following antenna relocation in 1997. Noting degraded transmission toward the north, a customized signal mapping system using a Yaesu FT-817, GPS, and software was developed to log real-time signal data. Calibration techniques extended the radio's signal range, enabling precise field measurements. The method allowed continuous signal strength monitoring while driving, revealing anomalies in coverage likely due to tower modifications. Findings helped assess and visualize the antenna’s actual radiation pattern and highlighted environmental impact on signal distribution.

Demonstrates the construction of 'The Virgin', a **direct-conversion receiver** specifically designed for the 40m amateur radio band. This project, completed in February 2016, features a fixed operating frequency determined by a crystal oscillator, requiring a physical crystal change to alter the reception frequency. The design incorporates two integrated circuits and a power regulator, emphasizing simplicity with a single control knob. The author details the initial design, subsequent modifications to the front end, and troubleshooting steps addressing common issues like audio motorboating and power supply instability. The resource presents the final design of the receiver, reflecting the author's first experience building such a unit between December 2015 and February 2016. It offers practical insights into basic circuit construction and the iterative process of refining a homebrew radio project. The content is particularly relevant for those interested in fundamental receiver principles and hands-on **QRP** transceiver building.

This resource details **cooling modifications** for Ameritron AL82, AL1200, and AL1500 HF amplifiers, specifically addressing heat issues encountered during high-duty-cycle digital mode operation. The author, WD4NGB, observed excessive heat in the tank area and band switch on an AL82, attributing it to insufficient exhaust over the 3-500 tubes and a complete lack of exhaust over the tank area. The modifications aim to prevent common failures such as damaged band switches and deformed insulating materials by increasing airflow and exhaust area. The page describes adding five holes to the chassis for enhanced cooling to the band switch and tank area, alongside enlarging the exhaust area over the inner 3-500 tube and the tank area on the amplifier cover, utilizing expanded metal for safety and RF shielding. The original cover featured 26.25 square inches of exhaust; the modified version significantly increases this to 48.5 square inches over the tubes and introduces an additional 15 square inches over the band switch. These changes are intended to resolve heating problems encountered during heavy, 100% duty cycle use in modes like RTTY or long SSB contests, which typically generate substantial heat. The article also discusses upgrading to a higher output fan, such as the G2E085-AA05-21, and modifying tube sockets for improved airflow and reduced back pressure, citing Tom Rauch (W8JI) of CTR Engineering as a source for parts.

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

Learn about Amateur Television (ATV) on the 23 cm band (1240-1300 MHz) in this article from the September and October 2000 issue of Mégahertz magazine. Discover how ATV adds a new dimension to QSOs by allowing hams to visit stations, transmit real reports on antenna installations, follow signal paths on camera, and have simultaneous sound transmission. Explore the world of ATV experimentation, comparison, and innovation, made easier by existing equipment in many ham radio operators' homes. Find out about the ATV bands, bandwidth requirements, and the 23 cm band as a starting point for ATV activities.

HamHAW (Ham Health and Welfare) is a pioneering platform that bridges the gap between emergency communication and community welfare. By leveraging the extensive ham radio network, we help locate missing persons and coordinate welfare checks during disasters when traditional communication infrastructure fails. Hamhaw mission is to provide emergency communications support to the public so those inside an emergency area can communicate their status and needs to authorities and the public at large.

Learn about North Carolina Packet Voice nets and NCPACKET YouTube videos. Get your NCPACKET Callsign Badge to wear at ham club meetings and hamfests. Explore Hamfest Photos and NCPacket news. Discover the North Carolina TARPN Nodes mission statement and the benefits of being off the grid. Find out why TARPN is a great option and compare it with Winlink, APRS, ARES, and MARS. Learn how to build the NCPACKET network, including information on repeater sites and other key components.

Service devoted to vacuum tube testing for HIFI, guitar, and vintage radio applications. Western Glow Tube Service offer a vintage radio repair service, they consider radio services more as a kind of tune-up, not a tradional repair service or restoration, although Level 3 is a nearly full restoration. Our services are geared toward radios that are mostly functional and not missing any significant parts except tubes.