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Station QRP presents various **circuit diagrams** for constructing low-power AM vacuum tube shortwave transmitters, catering to enthusiasts interested in vintage radio technology. The resource details schematics ranging from simple to more complex designs, enabling hams to build their own QRP AM transmitters for operation on frequencies like 6.925 kHz AM. It emphasizes the use of vacuum tubes, providing a technical foundation for understanding and replicating classic shortwave broadcasting methods. The content is geared towards those who enjoy the hands-on aspect of electronics and the unique characteristics of tube-based RF circuits. Building these transmitters allows operators to experience the nostalgia of early shortwave radio, with the site specifically mentioning a pioneer station on 6.925 kHz AM. The designs facilitate experimentation with low-power AM transmission, offering practical application for homebrew projects. The focus on QRP (low power) operation aligns with a segment of the amateur radio community that values efficiency and minimalist setups, providing a distinct alternative to modern solid-state transceivers.

an overview, introduction or tutorial about the basics of electronics filters including the types of filter and the various filter design considerations and parameters

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.

Harris DMR Manufacturer, provides advanced, technology-based solutions that solve government and commercial customers' mission critical challenges

Gimme Five reloaded, a compact 5 band QRP SSB transceiver in SMD technology. This unit covers 5 bands within the amateur radio spectrum (3.5, 7, 14, 21 and 28 MHz). Receiver is a single conversion unit with an interfrequency of 9 MHz. Transmitter uses 5 stages and has got a power level of 10 watts PEP output.

Dedicated to adventures in Ham Radio Technology

Valon Technology designs and manufacturers low cost, reliable radio frequency products such as RF Synthesizer modules, RF Frequency Dividers and Phase Gain Detectors. Main markets are military/defense, test engineering, radio astronomy, research centers and universities

Read all the key details about Vacuum Tubes or Thermionic Valves that provided the foundations for today's electronics technology.

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

Encrypted messages, fancy technology, spies use them all to communicate, but sometimes the best way to hide is in plain sight. Right now, broadcasting across the airwaves around the world, are automated, anonymous shortwave AM radio stations that most governments won't acknowledge even exist, much less explain

Microwaves101 provides an extensive repository of information covering fundamental principles of microwave design, targeting engineers and radio amateurs interested in the higher frequency spectrum. The site features a detailed _encyclopedia_ of microwave terms and concepts, alongside practical design considerations for various components and systems. It serves as a foundational reference for understanding RF propagation, transmission lines, and active/passive microwave circuits. The resource includes numerous calculators for impedance matching, filter design, and other critical RF parameters, facilitating hands-on project development. Discussions on **10 GHz** equipment and **24 GHz** projects highlight practical amateur radio applications, extending to operations up to 134 GHz. Content spans from basic theory to advanced topics like MMIC design and antenna characteristics, supporting both educational and practical endeavors in microwave technology.

Showcasing college amateur radio club activities, events, and projects. Informs visitors of up to date news items pertaining to ham radio technology used on campuses by students, faculty, and staff. A way for alumni to be informed of their clubs activities.

Ham Radio & technology for people with disabilities

Ban Power Line Technology a website devoted to defend amaterur radio against power line communications devices interferences

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.

An interesting article that compares tube amplifiers versus transistor amplifier.

OneSDR is an Education website with articles that simplify Software-defined Radio. Our goal is to demystify RF technology

This article discusses the Disk-Yagi antenna, also known as the "gun antenna," popularized by the video blogger KREOSAN. It explains the design, differences from standard Yagi-Uda antennas, and key features like the use of patch antennas and the integration of MIMO technology. The article covers the construction, tuning challenges, scaling issues, and provides insights on practical applications, such as optimizing signal performance with a 75-ohm antenna. It emphasizes that while DIY versions may vary, careful tuning and design are crucial for effectiveness.

Wuxi Venus Information Technology is an amateur radio devices dealer in China, source for high end, high performance RF products,Control products,APRS products and Commercial products. It provides a variety of solutions to the antennas systems, APRS,electronics kits and electronics components

Maybe not state-of-the-art technology but the author offers a quick and easy project for a Morse code practice oscillator using a 555 timer chip

The South Manchester Radio and Computing Club (SMRCC) provides a vibrant community for radio amateurs and computing enthusiasts in Sale, Cheshire, UK. Established as an active local club, it hosts regular weekly talks covering diverse subjects within both amateur radio and general computing. Members engage in various activities, fostering knowledge exchange and practical skills development across different facets of the hobby. The club's focus extends to supporting members in their pursuit of radio operating, technical projects, and digital communication methods. With a consistent schedule of meetings, SMRCC aims to be a central hub for local hams and those interested in the intersection of radio and computer technology. The club's activities contribute to the local amateur radio scene, offering opportunities for learning and social interaction.

Tuning into the airwaves for new and interesting transmissions has fascinated enthusiasts since the very earliest days of radio. As a result of advances in computer and radio technology, the equipment packed radio rooms of the past are now replaced by scanning receivers sometimes just the size of a mobile phone. What can radio receivers/scanners pick up? What types of radio receivers/scanners are there? What can and cannot be monitored legally? Best practice when using a radio receiver/scanner

Operating an amateur radio station effectively requires reliable coaxial cable to minimize signal loss between the transceiver and antenna. SIVA Cavi, an Italian manufacturer, produces a range of coaxial cables, including specific 50 Ohm low-loss types suitable for amateur radio applications. Their product line features cables like **RG 58 SHF1**, **RG 213 SHF1**, and **RF 400 SHF1**, which are commonly deployed in HF and VHF/UHF setups. The company also offers specialized cables such as the **HF 214 UF Ultraflex**, a high-performance broadband low-loss 50 Ohm cable designed for flexibility and reduced attenuation across various amateur bands. These cables are engineered with solid or foam dielectric materials, impacting their electrical characteristics and suitability for different power levels and frequency ranges. For instance, foam dielectric cables often exhibit lower loss at higher frequencies, a critical factor for VHF/UHF operations. Beyond amateur radio, SIVA Cavi manufactures cables for digital video broadcast, offshore marine use, and fire detecting systems, demonstrating a broad engineering capability in coaxial cable technology.

Explains the fundamental purpose of a repeater, detailing how these automated relay stations overcome distance and terrain limitations for VHF/UHF communications. It traces the historical development from early Bell Telephone Labs "relay" stations in 1922 to Art Gentry, W6MEP's, pioneering K6MYK amateur radio repeater in the mid-1950s, which remains active today. The resource clarifies the distinction between simplex and duplex operation, including the unique function of a "parrot repeater" for single-frequency recording and playback. Delving into the internal workings, the guide breaks down a repeater into its core components: the antenna system, feedline (often _Heliax_ or hardline for minimal loss), duplexer, receiver, transmitter, and controller. It emphasizes the critical role of the duplexer in preventing receiver desensitization by isolating transmit and receive signals, even with distinct frequencies. The discussion highlights the importance of high-performance, durable antennas and low-loss feedlines, citing examples of equipment installed in the 1960s and 1970s that are still in perfect working order. Operating a repeater is also covered, with an explanation of frequency offset (e.g., the 600 kHz standard for 2 meters) and the function of _CTCSS_ (PL tone) for access. It outlines standard input/output offsets for various bands, from 6 meters to 23 centimeters, while noting regional variations. The guide also touches on features like autopatch and Digital Voice Recorders (DVRs), providing a solid foundation for understanding repeater technology and usage.

A page dedicated tho the IC-756PROIII transceiver. This radio, discontinued, incorporates many of the features that made its predecessors so successful. However, the integration of the latest technology employed in the IC-7800 such as receiver technology, +30dBm class IP3, miniscope makes this new rig the very pinnacle of the IC-756PRO series.

The AN-55A ATV Handbook PDF is a document providing information and guidance on Amateur Television (ATV) for hams interested in setting up and operating ATV systems. The handbook covers topics such as equipment, setup, operating procedures, and technical details related to ATV transmissions. It is a useful resource for hams looking to explore the world of ATV and engage in video communications through amateur radio. The content aims to educate and inform hams about the intricacies of ATV technology and operation.

Professional Lithium-ion battery packs factory in Shenzhen China with more than 11 years experience in Battery business. Manufactured of Lithium ion and lithium polymer battery and Lithium battery packs.

About LoRa, wireless communication technology designed to transmit data over long distances. LoRa provides a means for wireless data transmission over long distances with low power consumption. Practical applications of LoRa in amateur radio

The Peilgruppe Neandertal, featured on Peilsport.de, actively promotes _Amateur Radio Direction Finding_ (ARDF), also known as fox hunting. This German group combines radio technology with outdoor sport, participating in regional and national ARDF events. Members access current ARDF schedules, competition results, and downloadable certificates directly from the site. The content highlights the adventurous spirit of ARDF, emphasizing the blend of technical skill and nature exploration. DL7ET and DR9P are noted callsigns associated with the group, indicating active participation from experienced operators. The site also covers related activities like Foxoring, a variation of ARDF that integrates orienteering with radio direction finding. This resource serves as a central hub for the Neandertal group's activities, documenting their involvement in a sport that challenges both physical endurance and radio proficiency.

Saluki manufacturer of Spectrum Analyzer, Handheld Spectrum Analyzer, Signal Analyzer, Cable and antenna analyzer, Network Analyzer|RF Signal Generator, Cable Antenna Analyzer

Manufactures Flyback, Switching, Audio, Toroidal, Current Sense & Custom Trasformer, Drumcore & PFC Inductor, Common Mode Chokes.

VARA HF is a soundcard modem that can be found on the HF bands exchanging traffic (Winlink). VARA implements an High Speed Data Mode and comes in 2 separate programs VARA FM and VARA HF. VARA is a High Performance HF modem based on OFDM modulation. VARA Modem, brings state of the art Military grade technology to new and existing HF data. Introduces a new standard of technology available for Amateur and Commercial use. Designed for operation within a SSB Bandwidth of 2400 Hz.

The Yaesu FT-710 is Yaesu s compact, shortwave transceiver that uses the SDR technology known from FT-DX101 and FT-DX10, which is a great fit for our fast-paced, comfortable world. The FT-710 is a perfect entry-level device. If you're thinking of buying a compact transceiver with SDR technology, it is a good choice.

System Fusion is Yaesu’s implementation of Digital Amateur Radio, utilizing C4FM 4-level FSK Technology to transmit digital voice and data over the Amateur radio bands

Dedicated to improving the skills of amateur radio operators around the world, utilizing education, competition, advancement of technology and scientific research, promoting international friendship and goodwill, and preparing them to better serve society in times of communication need.

Learn about the LinHT handheld SDR radio, an open-source, Linux-based project that is shaking up the ham radio and SDR communities. This guide is perfect for hams new to digital voice and interested in exploring experimental radio platforms. Discover what sets LinHT apart from traditional handheld radios, how it leverages SDR technology and Linux operating system, and why it's generating buzz in the ham radio landscape. Dive into the world of software-defined handheld radios with this beginner-friendly overview.

Filter Free is the shareware version of Filter Solutions and Filter Light. Filter Free is limited to 3rd order or lower low and high pass filters, 2nd order or lower band pass and band stop filters, and 10 tap or lower FIR filters, and does not include most of the advanced design capabilities of Filter Solutions and Filter Light.

From March 2 to March 11, 2018, a Norwegian team operated as Z2LA from Zimbabwe, focusing on 160m through 10m bands using SSB and CW modes. The operation, described as "holiday style," aimed to provide contacts for DXers worldwide seeking a rare DXCC entity. Key equipment included a SUNSDR PRO II, an Elecraft KX3, and an Icom 706 MK2G as a spare radio, supported by two Juma 1000 amplifiers for robust signal output across the bands. Antenna systems were tailored for multi-band operation, featuring an Inv L for 160m and 80m, sloping dipoles for 30m/40m, and a _Hexbeam_ from SP7IDX Technology covering 20m to 10m. For improved reception, the team deployed a SAL 30, two reversible BEV antennas from remoteqth.com, and a BOG from K1FZ, enhancing their ability to hear weak signals. QSL information directs operators to Clublog for log search and M0OXO Charles for OQRS, explicitly requesting no bureau cards. The team comprised LA7THA Rune, LA7WCA Arne, and LA9VPA Thor, successfully making numerous contacts and contributing to the DX community's pursuit of _Zimbabwe_ as a DXCC entity.

Four _Headway 38120_ LiFePO4 cells form the core of an 8AH 12V battery pack, designed for reliable emergency and field power in amateur radio operations. These batteries offer significant advantages over traditional lead-acid types, including a lifespan up to **10x** longer in charge/discharge cycles, lower internal resistance for faster recharging, and a flatter discharge curve that maintains voltage stability during use. Their inherent safety, being a flame-retardant technology, makes them a preferred choice for portable applications. Proper configuration, including parallel/serial setups, and careful charging/discharging protocols are crucial for maximizing battery life. Each cell has a nominal voltage of 3.2 volts, with a maximum charge voltage of 3.65 volts. A Battery Management System (BMS) is highly recommended to prevent overcharging or deep discharging, safeguarding the cells. The project emphasizes safety, noting the batteries' high short-circuit capacity of **200 AMPS** and the critical importance of incorporating an inline fuse between the battery pack and the load. Components like the battery holder, buss bars, and a suitable case are also detailed.

This page explores the world of Software Defined Radios (SDRs) in the context of amateur radio. It discusses how SDRs have revolutionized the hobby by reducing costs and enabling remote operation. The article provides ideas for projects and experiments that hams can undertake with SDR technology, highlighting the educational and experimental opportunities it offers. It also mentions specific examples of SDR projects like the Stoke on Trent SDR and SDR.HU. The content is aimed at amateur radio operators looking to explore and harness the potential of SDRs in their stations.

This article is from the book Ham Radio For Dummies and features some tips for portable amateur radio operations, on Field Day or generic outdoor operation, like selecting the proper antenna and portable power.

Practical Wireless is a doing magazine focusing on the practical and constructional side of amateur radio and appeals to all ages. Written by expert authors and contributors, Practical Wireless reflects developments in the technology, participants, activities and licensing framework of the hobby.

In his POTA activation, WK4DS experimented with radials for hamstick antennas. Despite sun and RF noise challenges, successful connections were made. Surprisingly, tuned radials proved unnecessary, simplifying setup. Hamsticks demonstrated versatility across frequencies. Increased power improved signal quality, sparking his curiosity for further exploration in radio technology.

This document provides a comprehensive guide on purchasing high-frequency (HF) high-power amplifiers, discussing key considerations such as new versus used models, tube versus solid-state technology, and troubleshooting common issues. It emphasizes the importance of understanding power needs for activities like DX chasing and contesting, alongside practical tips for selecting and maintaining amplifiers to ensure reliability and performance in various conditions.

This page presents the Arduino radio receiver project created by EasyEDA in 2024. It includes design drawings, BOM, and project details. The content is aimed at hams interested in building their own radio receiver using Arduino technology. The project is shared under a CC BY-ND 4.0 license, allowing others to replicate and modify it. The page also includes comments from project members, making it a useful resource for hams looking to explore radio receiver construction.

Learn how LoRa mode can be used for APRS and connected mode packet radio, offering low power and long-range communication. Discover the growing popularity of LoRa-only APRS devices and the use of LoRa boards from manufacturers like Lilygo, Heltec, and RAK. Find out about firmware options like Ricardo Guzman's CA2RXU firmware, which incorporates previous work and offers KISS for external APRS clients. Explore LoRa APRS frequency and modulation settings in the UK, and consider adding CA2RXU firmware to lora-aprs.live for more radio-specific information. Dive into the world of LoRa technology for ham radio operators and experiment with different firmware options.

This page discusses the use of the new Version 4 RTL-SDR dongle for simple QRSS reception. The author shares their experience with connecting the dongle to a PA0RDT miniwhip antenna and using RTLSDRlop QRSS software. They encountered issues with Linux but found a solution with a new driver. The page also provides information on coupling multiple dongles to one antenna and adding selectivity with a divider-filter box. Hams interested in experimenting with RTL-SDR technology, antenna setups, and software for QRSS reception will find this content useful.

Learn about the ZRS QRP-808 kit system for hams from the 1980s. Discover the improved features of the QRP-808 compared to the QRP-805, including the electrical diagram and assembly instructions. Explore the nostalgic journey of building and tuning this iconic amateur radio station, as shared by experienced ham radio operators. See original photos and insights from enthusiasts like Janko S55WT and Mirko S52PC, offering a glimpse into the history of amateur radio technology. Access PDFs for detailed views and immerse yourself in the world of DIY radio equipment construction and tuning.

Explore VK5DJ's experiments with the si5351a frequency synthesizer, a versatile device capable of generating frequencies from 8kHz to 200MHz. Learn how this I2C configurable clock generator can replace crystals and oscillators in various applications, providing stable and precise outputs. Discover how to program the si5351a for your own signal generator projects and repeater site setups. Utilize the affordable and efficient Adafruit module for reliable performance. Enhance your understanding of PLL/VCXO architectures and fractional dividers for frequency generation. Join the PDS Forum community in experimenting with this innovative technology.

Don Trynor, VA3XFT, created EvoHam to provide guides, reviews, and tools to help ham radio operators navigate the world of digital voice modes like DMR, D-STAR, Yaesu Fusion, P25, NXDN, M17, and FreeDV. The website aims to make this technology more accessible and enjoyable for beginners, intermediates, and experienced hams alike by offering clear and approachable information. With years of experience in the field, EvoHam is a modern hub for all things related to digital voice in the amateur radio community.