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The FT-991 is a nice small size and lightweight radio, it is perfect for portable operations. It can be carried along with a laptop computer as hand luggage in airplane. The weak point of this radio, is it does not have a separate RX antenna capability. Therefore i decided to add this feature. On the back side of the radio a BNC connector is added to connect the RX antenna and a switch is fitted to select between RX antenna or main antenna.

KM Rover is a rover logger software for BIG 4 VHF UHF contests and generic, Spring and Fall Sprints, GPS interface, beam heading CW PTT DVK functions. Works on Windows

An attic wire antenna with several modifications during the time. Began as a simple coax fed doublet antenna, and upgraded to a multi-band hf fan dipole, till the G5RV all deployed in an attic.

A small magnetic loop antenna, often employed by hams facing antenna restrictions or high local RFI, offers a compact solution for HF operation. This resource details the construction of a foldable magnetic loop designed for the 40m through 17m bands, emphasizing its high-Q factor and _Faraday coupling_ for effective noise rejection and narrow-band filtering. The guide outlines material selection, advocating for copper over aluminum to maximize efficiency, and provides insights into the physics governing its operation, including impedance matching and resonance principles. Practical application of this antenna design is particularly beneficial for QRP enthusiasts and portable operators seeking a stealthy, high-performance antenna. The construction process includes specific details for a 1-meter diameter loop, a 140pF variable capacitor, and a _gamma match_ for impedance transformation. Performance comparisons suggest that while a full-size dipole might offer slightly better gain, the magnetic loop's ability to mitigate local noise often results in a superior signal-to-noise ratio, making it a viable option for challenging RF environments.

This article explores the revival of the classic 3 Transistor Short Wave Radio kit originally offered by Radio Shack in the late 1960s. Updated with modern silicon transistors and components, the design retains its educational charm while enhancing performance. Detailed assembly instructions and illustrations are provided to facilitate replication. The project not only pays homage to nostalgic electronics but also serves as a practical introduction to radio theory, including modulation techniques and receiver types, fostering a hands-on learning experience for enthusiasts.

The Smith Chart, named after its inventor Phillip H. Smith, is a graphic tool used to solve transmission line problems in the field of ham radio operations. By using the Smith Chart, ham radio operators can determine the feed point impedance of an antenna, design impedance-matching networks, and optimize power transfer between a source and its load. The chart consists of resistance and reactance circles, providing a visual representation of complex mathematical relationships related to transmission line operations. Understanding and utilizing the Smith Chart is essential for hams looking to enhance the performance of their RF circuitry.

This page show a list of repeaters in north america transmitting from 28 MHz to 29 MHz. The most of them are in the 29.620 to 29.700 frequency range. Some repeaters may be active and on the air while others may not

Learn how to build your own QRPGuys DS-1 40-10m short vertical antenna for ham radio operators. This page provides detailed instructions on constructing this antenna, which covers the 40 to 10-meter bands. Whether you're a beginner looking to get started with antenna building or an experienced ham radio operator looking for a new project, this resource is useful for anyone interested in DIY antennas for portable or QRP operations.

The *SPACE* Amateur Radio over Internet Protocol (RoIP) system offers public audio transmissions from NASA Mission Control and astronauts, primarily for educational purposes. This service streams NASA public media sources, including *Artemis II* and the ISS public audio channel 2 feed, which predominantly features English communications. Astronaut activities on the ISS typically occur between 0700 UTC and 19:00 UTC, with transmissions most common during early mornings USA time, alongside special events such as launches or spacewalks. Users can connect to the live stream via EchoLink to the *SPACE* conference, via IRLP to the 0100 experimental reflector, or via Allstar to node 516221. EchoLink connections utilize the GSM CODEC, while IRLP and other connections default to uncompressed or u-law CODEC. The service notes that long periods of silence are common, and NASA audio sources can be periodically unavailable or noisy. Daily recordings of these transmissions are published at space.rfnet.link/recordings/, available as .ogg audio files for direct playback or .m3u8 playlist files for network streaming in applications like VLC. Each playlist file provides a list of timestamped audio transmissions, allowing users to review specific segments of interest.

A DIY cantenna can extend your WiFi range by building a 2.4 GHz high-gain antenna using accessible materials. The design, based on waveguide principles, uses a cylindrical tube to capture WiFi signals and can even connect to access points half a mile away in ideal conditions. While the ideal tube diameter was hard to find, a 4-inch aluminum dryer vent was chosen despite theoretical limitations. The cantenna offers a cost-effective, functional boost for your wireless network.

Online QSL archive counting 13400 QSL scanned and indexed online with a searchable database

Unveil the secrets of efficient Magnetic Loop Antenna control systems, eliminating the hassle of frequent retuning. With real-time tracking and compatibility with various transceivers, including popular models from Elecraft, ICOM, Kenwood, and Yaesu, this controller ensures seamless frequency adjustment. Explore its high-resolution stepper motor and versatile communication capabilities, revolutionizing amateur radio operation.

The earliest known historical record of the name Uzice is found in a document in the Ragusan archives, dated October 9th, 1329. In memory of this date, October 9th is now Uzice City Day. Earlier settlements in the vicinity date back to the Neolithic times. Throughout history, this area has been at a crossroads connecting economies and cultures North-South and East-West. To this day, Uzice is an important economic, industrial and cultural center. Award is active from October 1st to October 16th each year. To win you have to collect enough points making contacts (QSOs) with amateur radio stations which base locations are in the Uzice City Area.

This page provides construction details for a 4-element 10-meter Yagi antenna with 28 Ohm impedance. It includes information on the elements, positions, diagrams, and data related to frequency, gain, front-to-rear ratio, radiation resistance, SWR, and loss. The content is aimed at hams or radio operators interested in building and optimizing Yagi antennas for the 10-meter band.

UTSOURCE.net is a professional purchasing B2B & B2C tools in electronic components field. UTSOURCE provides different types such as IC, Modules, RF transistors, Electronic components, passive components

A PDF Presentation for beginners and all those hams tha t wish to approache the moonbounce operations. This presentation is focues on explaining how to begin EME operations withoud expensive or complex station setups, simply using common transceivers and some dedicated digital modes that nowdays are available to the ham radio community and well known.

Reviews for Elecraft K4 HF Amateur HF 6M VHF UHF at eham.net

Inverted L antenna, even if not completely freestanding, it only requires one line to be lauched into a tree to support the end of the horizontal wire. This project is done with a 31-foot Jackite pole for a support and uses six 15-foot radials and one 33-foot radial.

How to use a little known J-antenna characteristic to reduce a conventional 14 foot antenna to 7 feet. Perfect 50 Ohm match, same gain, no radials.

Homebrew a custom lithium battery pack with 5s3p batteries

Use this form to generate a list of amateur repeaters and broadcast transmitters to your specifications. The database covers the fifty U.S. states, the District of Columbia, and the ten Canadian provinces.

Designed for the FT-817, this audio speech compressor, centered on the Analog Devices SSM2165, offers a 40 dB compression range, enhancing signal power. Built externally with the SMD version to preserve warranty, the circuit interfaces smoothly with electret microphones. Testing shows a 6 dB average power increase. Adaptable to rigs with electret microphones, it maintains unity gain and 40 dB compression.

Online interactive elevationmap can help radio amateurs by predicting signal propagation, optimizing antenna placement, planning coverage, ensuring line-of-sight, mitigating interference, and enhancing emergency communication. T

The Butternut HF2V, originally a two-band vertical antenna for 80m and 40m, was enhanced by the user to include 30m and 20m bands for better digimode DX work during the solar minimum. The additions used components adapted from the HF6V and innovative methods for the 20m addition, either through a parallel vertical element or a lower-mounted independent element, minimizing band interaction. This modified four-band antenna now supports high power across popular HF bands using a single feedpoint.

This is a plan for an optimized element UHF Yagi Antenna for UHF Bands featuring a 9dBd forward gain, a 13 dB front-back ratio, and a bandwith of 10 MHz on the 430-440MHz range.

PH0NO conducted field tests comparing a mobile antenna (DX-UHV) to an end-fed half-wave wire. Results on 20m showed the end-fed wire outperforming the mobile antenna, with a significant difference in signal strength. On 40m, the end-fed wire surpassed the mobile antenna in spots and reach. While the mobile antenna is more practical, the end-fed wire offers superior performance. Further testing is planned.

Putting one of those old modems back into use.AMTOR is an acronym for AMateur Teleprinting Over Radio and was mostly used on HF. The mode is based on the marine SITOR code that was introduced to amateur radio by Peter, G3PLX. The mode is an enhancement of RTTY with active error correction that copes reasonably well with interference and fading.

The Shrunken Quad antenna is a unique design that offers full-sized performance on the 10m and 15m bands while incorporating linear loading via a trap for operation on the 20m band. This design allows for effective communication in the HF spectrum, making it suitable for both casual operators and serious DXers. The quad configuration provides excellent gain and directivity, which is beneficial for contesting and long-distance contacts. Constructing the Shrunken Quad involves careful attention to dimensions and materials to ensure optimal performance. The antenna's compact nature makes it an excellent choice for limited space situations, allowing operators to enjoy the benefits of a quad without the need for extensive real estate. This project is ideal for amateur radio enthusiasts looking to enhance their station's capabilities with a versatile and efficient antenna system.

This page is a discussion about impedance matching by Off Center Fed dipoles in the Wide L-form. When a vertical or horizontal dipole is bent into a 90 degree L-form, the impedance drops about half.

This DIY Yagi costs less than 20 Dollars, and let you increase the performance of your connection. With this project you can build a better Yagi beam antenna resonant on 850MHz, a 8 element yagi directional antenna

This blog post documents the author's journey building an APRS micromodem for amateur radio applications. Using an open-source design by LY2EN, the author assembled a cost-effective Terminal Node Controller (TNC) with SMD components, an Arduino Nano, and a JDY-31 Bluetooth module. The construction process included PCB fabrication, careful component soldering, microcontroller programming, and Bluetooth configuration. A custom 3D-printed case protected the completed device. Field testing in Romania showed the device functioned with a Baofeng UV-5R radio, though antenna limitations affected performance. The entire project demonstrates an affordable DIY alternative to commercial APRS trackers.

This project builds into a box into which you plug a Morse Code Key. Using the Morse Key creates realistic sounds so you can judge how well you Send. A great tool for beginners to improve Morse sending skills before going on-air

TX5N DX-peditionto Raivavae, Austral Islands, April 16 April 28, 2022

MorsePractice is a Java application originally written by Martin Minow (K6MAM) as an aid to learning Morse code. With morse practice you can select the digits you want the app to be transmitted. Additionally can be selected a random phrase, or random QSO.

A project for a six meters Yagi beam antenna, built mainly for portable operations. This is a 4 element Yagi beam with a 4 meters boom.

This page discusses the purchase of a fiberglass push-up mast for portable operations in the ham radio hobby. The author shares their experience with the MaxGain Systems MK-4-HD mast, highlighting its versatility for both home and on-the-go setups. They also detail modifications made to the mast base and provide insights on tube sizes for different antenna types. The content is useful for hams looking to improve their portable station setup and optimize antenna performance in various environments.

Doppler Whistles from Meteor Trails, few hams know that meteors can be spotted without leaving the operating room. Identifying Meteor-Trail Reflections, Shooting Stars, Why the Meteors Whistle

The small receiving loop (SRL) is a versatile and efficient antenna that can be simply built from common materials. It is designed for reception on the MF and HF bands and may be put in a variety of shapes and sizes. Despite its unusual installation, the porch loop in this case operated admirably, producing several DX spots on the 40m band. The SRL can be a great option for people looking to boost their reception on the MF and LF bands.

TX5S DXPedition to Clipperton Island 2024

Discover the secrets of Six Meters with this comprehensive eBook by Jim Wilson, K5ND. Learn about the magic of 6-meter DXing, including propagation, antennas, equipment, operating software, and more. Whether you're a beginner or an experienced ham radio operator, this book covers everything you need to know. With over 8,000 downloads, this updated version includes new chapters on FT8/FT4, MSK144, and Q65 modes, as well as contesting, rover operation, and awards. Get your hands on this valuable resource and enhance your 6-meter DXing experience today.

The 1/4 wavelength vertical antenna project, initially designed for 20 meters, has evolved into a versatile portable solution covering 10 through 60 meters. K0BXB details its construction, emphasizing a bottom-loaded design with a tapped loading coil and four 10-foot counterpoise wires. The author shares personal experiences and field results, including **18 QSOs** during a park activation on 17m and 30m with 10 watts, and a **2,435-mile** contact with a contest station in Bonaire on 20m using 5 watts. Comparisons are drawn to commercial offerings like the _Wolf River Coils TIA_ and _QRPGuys Triband Vertical_, highlighting the DIY antenna's small footprint, light weight, and ease of tuning for POTA activations. The resource includes insights into using test equipment such as the _NanoVNA_ for SWR optimization and discusses various radiator lengths, from 17-foot wire to a 102-inch whip, demonstrating adaptability for different portable setups. Construction tips cover coil winding, tap placement, and connecting feedlines and radials using common components.

The behavior of a straight dipole and its L-form is examined in terms of impedance and SWR. By adjusting the feed point or bending angle, impedance variation is observed. Impedance shifts symmetrically as the feed point deviates, leading to recommendations for optimal ratios. Model simulations aid in understanding and fine-tuning, crucial for achieving a 50 Ohm match. Practical tuning guidelines ensure efficient antenna performance.

G6HKS Yagi Kits & Parts provides material kits for building high-performance PowAbeam Antennas, ideal for VHF/UHF enthusiasts interested in DXing. The kits feature advanced Yagi designs, including the unique ParAclip system, ensuring exceptional all-weather stability and minimizing detuning effects. With resources, tips, and support, the site aims to make antenna construction straightforward for amateur radio operators. The focus is on delivering top-tier performance at competitive prices, empowering users to build and enjoy their own high-quality antennas.

NetFinder is the ultimate directory for Ham Radio and SWL enthusiasts, designed to connect Amateur Radio operators through organized nets. Nets are scheduled gatherings on specific frequencies, ranging from formal emergency communication training to casual chats among Hams. Offering a platform for camaraderie and skill-building, NetFinder simplifies the process of discovering nets, fostering deeper engagement in the hobby. With a vision of cataloging every net worldwide, NetFinder aims to make these vital connections accessible to all operators, enriching the Amateur Radio community.

The Thevenin equivalent simplifies a complex circuit into an equivalent circuit with a voltage source and resistor for easy analysis of voltage and current at any point in the circuit. Use this online Thevenin calculator

Digital modes troubleshooting can be complex, even with devices like Digirig, which are designed for ease of use. This guide provides solutions for common setup issues in ham radio digital modes, applicable to Digirig and similar interfaces. Key troubleshooting tips include isolating problems, restoring previous configurations, ensuring correct USB and audio connections, and configuring software and hardware settings properly. Community forums offer additional support for specific issues.

A collection of pictures for a mobile antenna setup for T-hunting.

Learn how an experienced ham radio operator rebuilt his trap dipole antenna for 30, 40, and 80 meters after a storm damage. Discover the process of upgrading to a short trap dipole for 40, 80, and 160 meters using double-wound traps made from RG-58 coax. Follow along for construction details and tips on building this unique classi.

The Worked All Britain Awards Group (W.A.B.) was devised by the late John Morris G3ABG in 1969. This was to promote an interest in Amateur Radio in Britain and to sponsor a series of awards based on the geography of Great Britain and Northern Ireland.

This page gives a brief description of a 70 MHz transverter that has been published in the Danish amateur radio magazine "OZ." This way hams outside Denmark may also benefit from the design.