Search results

Oscilloscope, Realtime spectrum analyzer, Impedance meter, RLC bridge and signal generator for Windows. Is a Windows application that converts your PC into a powerful dual-trace signal analyzer (oscilloscope, FFT etc...) . Uses your PC sound card as an Analog-to-Digital a Converter to digitize any input waveform and as Digital-to-analog Converter for the signal generator. True 24 bit adc/dac 48K/96k/192k sampes/sec.

This sketch will read RF power and SWR from any SWR bridge, designed to work on VHF UHF bands

Wire antennas requires a special coupling network to properly couple my 50 ohm coax to the antenna's high impedance (5000 ohms)

by Harry Lythall SM0VPO

End-Fed Half-Wave Antennas (EFHWAs) are analyzed for their utility in portable QRP operations, emphasizing their simplicity, efficiency, and predictable radiation patterns compared to other portable antenna types. The discussion contrasts EFHWAs with vertical antennas, random length wires, and center-fed dipoles, highlighting the common pitfalls of each, such as ground system dependency for verticals and feedline issues for dipoles. The article details the electrical half-wavelength calculation using the formula L (Ft) = 468/F(MHz) and explains how EFHWAs can be resonant on harmonic frequencies, enabling multiband operation. Various deployment configurations are presented, including the inverted L, inverted Vee, sloping wire, and vertical setups, each with specific advantages for radiation angle and polarization. For instance, a vertical EFHWA offers a low angle of radiation suitable for DX contacts without requiring an extensive ground system. The resource also addresses the counterpoise requirements, suggesting a quarter-wavelength wire or connection to a metallic structure for decoupling. A schematic diagram for a simple parallel-tuned circuit tuner, based on the _Rainbow Bridge/Tuner_ design, is provided, detailing component values for 30 and 40 meters, including a 6 microhenry toroidal inductor and a 20-100 picofarad mica compression capacitor. The tuner's adjustment process for SWR matching is also outlined.

CQiNet is a family of programs that combine Ham Radio with the Internet using Voice over IP (VoIP) technology. Two programs are currently in the family, "theBridge" and echoLinux. Thebridge is a iLink/EchoLink compatable conference bridge that runs under various versions of Unix as well as Windows. EchoLinux is a EchoLink client program for the Linux operating system.

Dedicated to building bridges between the EME, SETI and Radio Astronomy Amateur Interest Groups.

Police and Security Broadcasts at Harvard University, Boston-Area University Police Radio. Cambridge; Boston.

Radio Amateurs serving Prince William County Virginia

Presents the DBO274 Citizen Band mailbox, a digital communication hub accessible via HTTP and Telnet, specifically catering to **CB radio** enthusiasts in Germany. This resource outlines its functionality for Packet and other digital emissions on the 11-meter band, a segment often overlooked by traditional amateur radio operators but vital for CB users seeking advanced communication methods. The author, DH8YMB, provides insights into its operation, reflecting practical experience with digital modes in the CB spectrum. The DBO274 serves as a bridge, enabling users to exchange messages and data packets, extending the reach and utility of standard CB transceivers. It represents a localized digital infrastructure, demonstrating how the 27 MHz band can support more than just voice contacts, incorporating elements of early internet-like communication within the CB community. This setup highlights the enduring innovation within the CB realm, adapting technologies like Packet Radio for a different user base. It underscores the versatility of radio communication, even on less conventional bands, for those interested in digital data exchange beyond the typical amateur allocations.

The 9A3MR contest QTH rental provides a fully equipped amateur radio station for DXpeditions or radio holidays on Murter Island, Croatia. The station features a Drake TR7 transceiver and a 16-meter tower with a rotator, suitable for various HF operations. Accommodations include a four-room apartment and a studio apartment, both within 200 meters of the beach, offering amenities like parking and a barbeque area. This QTH is located in Jezera, a fishing village with local stores and restaurants within a five-minute walk. While Murter Island itself does not qualify for IOTA due to a bridge connection, the Kornati Islands National Park (IOTA EU-170) is only 10 nautical miles away, with daily tourist tours available. The Krka National Park is also accessible by car, approximately 25 km distant, providing additional recreational opportunities.

Manufacturing distributor of infrastructure products for the telecommunications industry; antenna mounts, ice bridge, cable ladder, ground bars, weatherproofing, exothermic, safety equipment.

Transverters-Store is a online shop for low cost transverter boards, but also QRP transceivers, Active antennas, RF bridge and probes, Mic equalizers and other amateur radio accessories

Do you want to measure antenna impedance at resonance? With this Antenna Scope, you have a simple RF Bridge for getting started in an exciting part of Ham Radio, building your own Antennas that work well

Cambridge, Ohio

Examines JPS Communications' product offerings, focusing on their contributions to Radio over IP (RoIP) and Push-to-Talk over Cellular (PoC) technologies. The resource details how JPS solutions enhance Land Mobile Radio (LMR) capabilities by providing secure and cost-effective methods for communication expansion and interoperability. It highlights the company's 30-year history in developing infrastructure to make communication systems more versatile, secure, and robust, addressing critical needs in various operational environments. The content specifically outlines JPS gateways that bridge traditional radio systems with PoC solutions, facilitating seamless communication across disparate technologies. It also describes multiple approaches for expanding LMR coverage beyond conventional system limitations. The information presented underscores the practical application of these technologies in achieving communications interoperability, irrespective of the underlying systems or protocols, aiming to improve operational efficiency and safety.

The Dilawri Cardiovascular Institute (DCI) is a prominent Canadian organization dedicated to advancing cardiovascular health through cutting-edge research, equitable patient care, and medical innovation. It integrates 16 core centers, including specialized units like the Centre for AI, Data Science, and Imaging, and the Centre for Heart Rhythm, to bridge research findings directly into clinical practice. Their mission emphasizes providing world-class cardiac care accessible to all patients, regardless of their geographic location, by employing disruptive innovation and creative strategies to reach individuals faster. The institute focuses on a team-based approach, ensuring patients receive the correct therapy at the optimal time for long-term well-being. DCI's commitment extends to continuous growth through education, pushing boundaries beyond standard care, and fostering a respectful, inclusive environment for both staff and patients. They lead industry collaborations to shape the detection, treatment, and management of heart disease.

A DX and Contest Minded Amateur Radio Club Serving the California Coast North of the Golden Gate Bridge

Greater Bridgeport Amateur Radio Club helps to provide vital Emergency Communications through amateur radio to Southern Fairfield County and the Derby area.

Bridgewater MA USA

Formed in 1987, serve the west part of Cambridgeshire that straddles the valley of the river Great Ouse and was the old county of Huntingdonshire. This includes the market towns of Huntingdon, St Neots, St Ives and Ramsey.

Raspberry Pi to Clublog bridge that consumes broadcasted QSOs from N1MM, transforms the QSOs into ClubLog ADIF format and sends those QSOs in batch or real-time to ClubLog automatically

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.

Over 1900 ARISS school events have been conducted since 2000, facilitating amateur radio contacts between students and ISS crew members. This resource details the Amateur Radio on the International Space Station (ARISS) program, outlining scheduled contacts, operational procedures, and application processes for educational institutions worldwide. It lists specific upcoming contacts, such as those with Lewis Center for Educational Research in California and Vauban, Ecole et Lycée français de Luxembourg, typically operating on a 145.800 MHz downlink frequency. The content also provides crucial guidelines for radio amateurs, emphasizing the importance of not interfering with scheduled school contacts and utilizing the crossband repeater for general QSOs when available. It clarifies crew availability for casual contacts, noting that astronauts are usually free during personal time, approximately one hour after waking and one hour before sleeping, and often on weekends. Constraints on scheduling, such as avoiding EVA weeks and specific crew rest periods, are also detailed. Furthermore, the resource includes historical statistics on direct versus telebridge contacts, QSL information, and links to related ARISS, AMSAT, ARRL, and NASA websites. It also provides information on applying to host an ARISS contact for schools and youth organizations in various regions, including the United States, Europe, Africa, the Middle East, Canada, Central and South America, Asia, and Australia.

Noise bridge circuit to tune your tuner

Sort of similar to the one of the 6m omni. Instead of using twin-lead, this design makes use of a more or less regular double bazooka antenna (coaxial dipole). Your attention shall be drawn to the available standart literature, such as Rothammel. In order to "compute" the dimension, Karl Rothammel mentioned that the total length of the dipole shall be 95% of the free-space wavelength. The short-circuit bridges (closing the folded dipole) are to be placed at a distance-fraction being equal to the velocity factor of the coax cable used, which will be 66% using RG-58 or RG174.

Cambridgeshire England Direction Finding group

The Cambridge University Wireless Society (CUWS) serves as the amateur radio society for students and staff at Cambridge and Anglia Ruskin Universities, fostering interest and activity in two-way radio communication. It provides a platform for members to engage with various aspects of amateur radio, including operating, technical experimentation, and community building within the university environment. The society's activities typically encompass station operation, antenna construction, and participation in contests and DXing. As a university-affiliated club, CUWS offers practical experience in radio theory and application, often utilizing the club callsign _G6UW_. Members learn about different modes of operation, such as CW, SSB, and digital modes, and gain hands-on experience with transceivers and associated equipment. The society's focus includes preparing members for amateur radio licensing exams and promoting ethical operating practices. Participation in CUWS provides a foundation for future involvement in the broader amateur radio community.

This Return Loss Bridge has been designed to characterize the input impedance of a receive strip, and the output impedance of a transmit strip

DataBridge wireless RF modem modules facilitate point-to-point data transmission, supporting analog, digital, and serial RS232 UART signals. These modules are engineered for robust wireless communication, offering a reliable solution for various industrial and amateur radio applications requiring secure data links. The product line includes specific models designed for different frequency ranges and power outputs, ensuring compatibility with diverse operational requirements. Each module integrates advanced RF technology to maintain signal integrity over distance, crucial for remote monitoring and control systems. The design emphasizes ease of integration, allowing users to quickly deploy wireless data links without extensive configuration. Key features encompass low power consumption and a compact form factor, making them suitable for embedded systems and portable devices.

G2XV G8EVY 1919 - 2010 Promoting Amateur Radio in Cambridge for over 90 years

Two beacons in 3 and 1.2 cm band, 10368.755 MHz and 24048.870 MHz

A Simple Serial and Sound-Card Interface for the Yaesu FT-857D using an FT232R USB-to-serial bridge chip.

The Camb-Hams are an informal group of Cambridgeshire Radio Hams.

The Digital Communications Interconnect (DCI) resource details the operational philosophy and technical implementation of an open _MotoTRBO_ IPSC network, emphasizing the use of _c-Bridge_ technology for interconnecting DMR repeaters and talkgroups. It outlines the group's mission to facilitate dynamic connections within the regional DMR amateur radio community by openly sharing network resources and talkgroups, promoting independent network growth and exploring the capabilities of c-Bridge linking. The site provides insights into the technical advantages of c-Bridges, such as breaking the finite peer slot limitation of simple IPSC networks and enabling more flexible talkgroup routing beyond two timeslots. This legacy asset, last updated in October 2022, also reflects on the group's history and challenges encountered in national DMR efforts, citing political divisiveness among major c-Bridge groups. It discusses the practical application of c-Bridges for emergency communications and nets, ensuring redundant talkgroup servers for smooth day-to-day operations and priority events. The resource encourages other c-Bridge operators to adopt international talkgroups like "_iCall Talkgroup_" and a nationwide "Emergency Talkgroup," while also offering guidance on affiliating repeaters or IPSC networks with DCI's open network.

Paul McMahon presents a compact VSWR meter designed for QRP portable use, ideal for SOTA operations with rigs like the FT817. The device, constructed from readily available components, employs a simple resistive bridge for wideband performance from 1.8MHz to 52MHz, with diminishing accuracy at higher frequencies. Key features include no need for external power, simple calibration, and operation with low power levels. The design, detailed with parts lists, schematics, and construction guidelines, ensures a 2:1 worst-case VSWR to protect transceivers during antenna matching. Calibration points are set for accurate VSWR readings at various loads.

The Fuchs Antenna tuner with a resonant circuit as a coupler. The Fuch Antenna Tuner is providing a high-efficiency compare to a 49:1 transformer using ferrite . The Fuchs tuner is a resonating L/C circuit to step-up the impedance from 50 Ohm to the required 3k. The ATU is able to perform automatic tuning with the addition of a tiny Aduino Nano and a SWR bridge.

Low Cost Satellite Antennas article was originally presented at a Project OSCAR seminar on September 30th, 1990. AMSAT-UK printed an abridged version of this presentation in their OSCAR News, Number 88, April 1991. The original presentation has been reedited and updated for AMSAT's Web page.

Our mission is to provide our customers with a communication solution that fits a need and provide high quality customer service. We specialize in the development and sale of communications equipment for land mobile radio, amateur radio, commercial radio and RoIP (Radio Over IP) solutions.

This innovative antenna tuning unit (ATU) enables QRP operators to match their antennas without transmitting RF signals. Using a noise bridge technique instead of traditional transmit-and-tune methods, it achieves truly silent operation. The design incorporates an L-match network with switched inductors and variable capacitor, handling impedance matching from 3-30MHz. Operating from a 9V battery, it includes a built-in RF power meter and dummy load for QRP transmitter testing. The compact unit is particularly suitable for portable operations where minimal RF emissions during tuning are desired.

SWR Magazine is free montlhy ham radio online magazine published in English and Spanish. SWR Magazine presents a mix of analysis, hands-on experience, and technical insight for ham radio operators. Covering global radio trends, technical topics like antenna takeoff angle, operating practices outside the shack, reviews of radios, propagation. Explore innovative antennas, digital modes like RTTY, and historical radio origins. This issue bridges the past, present, and future of amateur radio, inviting readers to not just read, but experience and experiment with the content.

In the pursuit of an affordable matching and SWR indication solution for the Pixie-based transceiver system this T-Tuner and SWR bridge unit, while not groundbreaking, proves to be a cost-effective performer. With real-world impedance testing yielding a worst-case loss below 0.9 dB, the unit efficiently matches all bands on 80 M to 10 M ham bands, making it a valuable addition to the QRP system.

A group from Cambridge University Wireless Society will be QRV from the UK Sovereign Base Area on Cyprus as ZC4UW from 2-7 January 2020 with a maximum of 4 stations.

We are a group of amateur radio operators located in Northern Utah who enjoy exploring many aspects of the hobby from HF to VHF and beyond. We are active in many public service events, Field Day, APRS, packet, Winlink, contesting and more

Hams over IP (HOIP) is a VoIP comunication service provided by amateur radio community that offer Bridges and HoIP Extensions to ham radio opetors allowing phone communication over the internet.

Getting started with Aircraft scatter, defined as the process of scatter radio waves of the body of a traveling aircraft in order to enhance the distance possible to bridge on VHF, UHF and microwaves. The ACS path, Equipment requirement and Operating techniques

The Beam project offers various features for controlling antenna rotators, including support for 2 or 4 line LCD displays, software or hardware clocks, open collector drives for azimuth and elevation control, and internal calculations for tracking the sun and moon. It can also track satellites and supports "Flip Mode" for inverted antennas. The 4-line version provides detailed readouts while the 2-line version offers a more compact display. New versions now support PWM and I2C H-bridge modes for adjustable speed control at the end of a move.

The Yaesu VX-6R USB Programming Interface is a reliable solution for programming the Yaesu VX-6R handheld radio using USB. Based on the FT232RL chip, it replaces older RS232 interfaces and USB converters, ensuring stable communication. The design integrates a buffering circuit with a Sparkfun breakout board, featuring TX and RX LEDs for easy monitoring. The compact interface connects to the radio via a four-pin header, with a solder bridge option for radios requiring separate data lines. This setup has proven reliable and versatile, allowing the FT232RL to be repurposed for other projects.

This page provides detailed instructions on how properly setup the Win-Test contest logging application for windows with the popular Yaesu FT-991 transceiver by installing properly the UART Bridge COM to USB port drivers to properly set the switched inside the Win-Test application.

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.