Search results

Presents the official online presence for Yaesu, a prominent manufacturer of radio communication equipment. The site details their extensive product lines, encompassing amateur radio transceivers, antenna rotators, tuners, amplifiers, and various accessories like microphones, speakers, and power supplies. It functions as a central hub for product information, specifications, and support resources. The resource categorizes its offerings across several key areas, including **Digital Mobile Radio (DMR)** solutions, HF/VHF/UHF transceivers, and specialized receivers and scanners. Each product section typically includes model numbers, feature highlights, and often links to manuals or technical documentation, providing hams with essential data for equipment selection and operation. Beyond amateur radio, the site also covers Yaesu's contributions to aviation and marine radio sectors, illustrating the company's broader scope in wireless communication technology. It serves as a direct portal for accessing manufacturer-provided details, ensuring accuracy and currency for those researching Yaesu gear.

The project details a DIY SWR/Wattmeter designed around an _Arduino Uno_ shield, providing capabilities to measure RF power from 2 to **200 watts** and Standing Wave Ratio (SWR) for HF amateur radio bands. This construction features a compact design, integrating the measurement circuitry directly onto a custom PCB that interfaces with the Arduino Uno microcontroller. Key components include a directional coupler for sensing forward and reflected power, precision rectifiers, and analog-to-digital conversion for processing RF signals. The Arduino firmware handles calibration, calculations, and displays the results on an integrated LCD, offering real-time feedback on antenna system performance. The design prioritizes simplicity for homebrewers. Performance specifications indicate accurate readings within the **2-200W** power range, suitable for typical QRP to medium-power HF operations. The project provides schematics and a basic overview of the software logic.

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.

The PIC-MORSE is an electronic iambic keyer, integrating a generator of Morse code and a sidetone. It is built with a microcontroller PIC16C711. In French

Build your own home made Antenna Analyzer with an arduino micro, or a cheeper one with a pic processor

This resource details the construction of a versatile CW/QRSS beacon, designed around a Microchip _PIC16F84_ microcontroller. The project provides a flexible platform for transmitting either standard CW or very slow QRSS signals, making it suitable for LF, VHF, UHF, and SHF applications. It supports two distinct messages, each configurable for speed (from 0 to **127** WPM for CW, or up to **127** seconds per dot for QRSS) and repetition within a six-phase sequence. The core functionality relies on the PIC's EEPROM, which stores all operational parameters, including message content, transmission speeds, phase configurations, and relay control settings. This design allows for parameter modification directly via programming software like _ICProg_ without altering the main program code. The project includes a detailed schematic, a component list, and an explanation of the EEPROM memory mapping for messages, speeds, phase settings, and inter-phase delays. General-purpose outputs (OUT1, OUT2, OUT3) provide dry relay contacts for external control, enabling functions such as power switching, antenna selection, or frequency changes. A 'TRIGGER' input facilitates controlled starts or continuous free-run operation. Sample EEPROM configurations illustrate how to program specific beacon sequences, including message content and relay states.

Demonstrates the construction of two distinct wideband RF preamplifiers, detailing their component requirements and performance characteristics. The first design leverages monolithic microwave integrated circuits (MMICs) such as the MAR-6, MAR-8, or PGA103, offering a broad frequency response from DC to 2 GHz with a gain of 22.5 dB at 100 MHz and a noise figure typically below 3 dB. This MMIC-based amplifier incorporates protection against power supply transients and features a 50 Ohm input/output impedance, operating from an 8-20 volt supply with low current drain. The second preamplifier design utilizes a BSX-20 transistor, providing amplification across the 14 MHz to 550 MHz range. This simpler, more economical build achieves an average gain of 12 dB at 145 MHz and a noise figure of approximately 1.1 dB. It operates from a 7-15 volt battery supply with a current draw of 6 mA. Both projects emphasize critical construction techniques, such as maintaining short RF connections, ensuring 50 Ohm impedance paths, and mounting the circuit within a shielded enclosure to optimize performance and minimize noise. The resource also discusses phantom power options for antenna-mounted preamplifiers and precautions for use with transceivers, including output protection diodes and static bleeders.

Free programming software for various of the MicroChip PIC series of micro-controllers by Nigel Goodwin

For amateur radio operators engaged in **radio direction finding** (RDF) and **transmitter hunting** (T-hunting) activities, this resource provides a catalog of printed circuit boards (PCBs) for constructing various DF and foxhunt-related projects. The offerings include PCBs for 80-meter fox transmitters and receivers, UHF fox transmitters with audio recording capabilities, and several designs for general-purpose radio direction finders. Specific projects like the "Simple 80M ATX-80 Transmitter" and the "N0GSG DSP Radio Direction Finder" are listed, along with attenuator boxes and specialized components for Doppler DF systems. The catalog details PCBs for projects published in prominent amateur radio magazines such as *73's*, *CQ*, *QST*, and *PE*, indicating their origin and design pedigree. For instance, the "Montreal Fox Controller" is sourced from the *Homing-In* column by Joe Moell, K0OV. The resource also lists components for advanced Doppler DF systems, including main boards, LED display boards, and antenna switch boards, with options for programmed PIC microcontrollers. Pricing for each PCB is provided, allowing hams to acquire the necessary components for their DIY RDF endeavors.

Hidden transmitter hunting, often called fox hunting or Amateur Radio Direction Finding (_ARDF_), presents a unique challenge for radio amateurs. This resource details the _PicCon_ controller, a specialized device designed to automate the transmission of signals for such events. It integrates with a standard radio transceiver, functioning similarly to a packet radio TNC, by controlling the Push-To-Talk (PTT) line and injecting audio tones or modulated CW Morse code into the microphone input. The _PicCon_ unit is field-programmable using DTMF tones received via the radio, storing all settings in EEPROM for power-off retention. Its compact design and low power consumption (a few milliamps from a 7-35VDC source) make it suitable for remote deployment. An onboard LED indicates operational status, and a push-button allows manual start/stop of transmissions without DTMF. Typically supplied as a kit, _PicCon_ includes a PCB, components, and a comprehensive manual (available in HTML, RTF, and PDF formats). The kit provides a six-conductor interface cable, but users must supply radio and power plugs due to varied configurations. Byon, _N6BG_, developed this controller, which is available from the Byonics website.

Showcasing a specialized product line, Advanced Receiver Research presents a comprehensive catalog of **low noise preamplifiers** and microwave **Gunnplexers**. The offerings span a broad spectrum of radio frequencies, from VLF, LF, MF, and HF bands up through VHF, UHF, and microwave, catering to diverse applications including amateur radio, commercial installations, and military systems. Their product range includes mast-mount preamplifiers, inline attenuators, power dividers, and various coaxial components. My own experience with similar low-noise front ends for weak-signal work on 2 meters and 70 centimeters underscores the critical role such components play in maximizing receiver sensitivity, especially when chasing distant DX or engaging in EME. The detailed product descriptions and technical specifications provided on the site allow operators to select the optimal preamplifier for their specific band and noise figure requirements, essential for improving signal-to-noise ratio. The site also lists specialized products for unique applications like Nuclear Magnetic Resonance (NMR) and Studio Transmitter Links (STL), demonstrating a depth of engineering capability beyond typical amateur radio fare. This breadth of offerings, coupled with clear ordering and warranty information, positions Advanced Receiver Research as a key supplier for high-performance RF components.

Enhanced SSB Audio (ESSB) is a specialized operating mode that extends the capabilities of traditional Single Sideband (SSB) voice transmissions. This presentation by K4QKY delves into the technical aspects of ESSB, discussing its advantages and the ongoing debates within the ham radio community regarding audio quality and bandwidth usage. ESSB aims to provide clearer and more natural-sounding audio, which can enhance the overall communication experience for operators. The presentation covers various topics, including microphone selection, audio processing techniques, and the importance of proper equalization. It also addresses the controversies surrounding ESSB, such as the potential for interference and the debate over whether it strays too far from traditional SSB practices. By understanding these elements, amateur radio operators can make informed decisions about their audio setups and contribute to discussions about the future of SSB operations.

Electro-Voice Model 664 (EV 664) cardioid microphone, wiring diagram, pictures and data sheet

A hombrew QRP transceiver for 40 meter band with many pictures, circuit and sound recording of some QSOs made with this Rig consisting of 5 transistor and one chip.

The MEL PICBASIC Forum serves as a community hub for users of Micro Engineering Labs PICBASIC compilers, facilitating discussions related to PIC microcontroller programming. It features dedicated sections for various compiler versions, including mel PIC BASIC, mel PIC BASIC Pro, and PBP3, each containing numerous threads and posts detailing specific programming challenges and solutions. The forum also provides areas for frequently asked questions, general PIC BASIC discussions, and commercial assistance requests. Specific sub-forums address advanced topics such as PBP Extensions, Code Examples, and AI and PICBASIC, offering insights into extending compiler functionality and integrating artificial intelligence concepts. Furthermore, the platform includes sections for Data Communications, covering USB, I2C, 1-Wire, GSM, and serial communications, which are critical for interfacing PIC microcontrollers with external devices. A dedicated area for PIC Programmers allows for discussions on programming hardware and techniques. The forum's utility is enhanced by its extensive archives of user-contributed solutions and examples, which can assist hams in developing microcontroller-based projects for radio applications. The platform's structure supports knowledge exchange among hobbyists and professionals working with PIC microcontrollers.

A good reference site for antique radio, bakelite paskon plastinc decription, microphones picture and antique radio gallery

The North East Weak Signal Group (N.E.W.S.) website serves as the digital hub for an ARRL-affiliated regional club dedicated to _weak signal_ work across the VHF, UHF, and SHF spectrum, from 50 MHz up to light. It provides essential information for members and prospective enthusiasts, including the club's constitution and by-laws, details on officers and the board of directors, and a calendar of meetings and events. The site also features an application for membership, information on dues, and a membership roster, fostering a sense of community among its over 100 members. A significant feature of the site is its extensive archive of conference papers, including proceedings from the _Eastern VHF/UHF/Microwave Conference_ dating back to 2009. These papers cover a wide array of technical topics relevant to weak signal operations. The site also lists _50 MHz Beacons_ and _144 MHz and up Beacons_, along with links to other VHF and above resources, providing practical tools and knowledge for operators interested in pushing the boundaries of amateur radio communication.

PIC micro controller based frequency counter with LCD readout

Japanese electronic parts online shop offer a wide range of products, from microchip pic to leds and batteries to any kind of connectors

Accurate frequency measurement is crucial for amateur radio operators, particularly when building or troubleshooting transceivers and test equipment. This resource details the construction of a _PIC microcontroller_-based frequency counter, providing a practical solution for precise frequency display. The design incorporates an LCD readout, offering clear visual feedback of measured frequencies. The counter can operate as a standalone unit, useful for general bench testing, or be integrated directly into a receiver. Its built-in offset functionality allows for seamless integration, enabling the display of the received signal frequency rather than the intermediate frequency. The project focuses on accessible components and construction techniques, making it suitable for homebrew enthusiasts. Key features include a measurement range up to **50 MHz** and a compact form factor.

A 200 kHz bandwidth digital transmission system for image transfer in the Amateur Service is under development, specifically targeting VHF allocations. John B. Stephensen, KD6OZH, leads this project under an FCC Special Temporary Authority (STA) valid until September 10, 2006, authorizing emissions up to 200 kHz bandwidth in the 50.3-50.8 MHz segment. Current regulations typically limit bandwidths to 20 kHz on VHF amateur bands, making this STA crucial for testing wideband digital modes. The modem, a modified **OFDM** (Orthogonal Frequency Division Multiplexed) unit, was initially tested on the 70-cm band. It splits a high-rate data stream into multiple low-rate subcarriers to mitigate multipath echoes. The system uses a DCP-1 card with a Xilinx XC3S400 FPGA and Oki Semiconductor ML67Q5003 microcontroller. The transmitter, located at 36d 46m 30s N, 119d 46m 22s W, generates 150 WPEP into an 8 dBi gain vertical antenna, while the mobile receiver uses a Ham-stick. Three data formats for 50, 100, and 200 kHz channels are being tested, with encoded data rates of 96, 192, and 384 kbps. Verilog code for the VHF OFDM modem is 95% simulated, with modifications from the UHF version including increased filter coefficient precision and a change from Ungerboeck **TCM** to BICM for improved performance over fading paths. Final tests will involve one-way over-the-air measurements of bit error rates and coverage area.

The M0KGK keyer with variable speed and weight controls utilising a low cost PIC microcontroller.

P16PRO and PICALL Microchip PIC programmer

Amateur Radio 40m 20m 15m Half Wave Fan dipole antenna project with part list, pictures and drawing. Includes the option to expand the antenna to cover the 80 meters band

This project describes the construction of a real CW QRP keyer with a small microcontrolle

The m0xpd keyer project utilizes a PIC16F628A microcontroller, offering Iambic A and B modes, adjustable speed from 5 to 40 WPM, and variable weight control. It incorporates a sidetone generator with adjustable frequency and volume, along with a PTT output for transceiver control. The design includes a 16-pin DIL IC socket for the PIC, a 3.5mm stereo jack for the paddle, and a 3.5mm mono jack for the PTT output. Powering the keyer requires a 9V DC supply, which is regulated down to 5V for the PIC. The circuit board layout is designed for through-hole components, facilitating home construction. A detailed schematic and a parts list are provided, guiding builders through the assembly process. The project also discusses the firmware programming for the PIC16F628A, essential for the keyer's functionality. Construction details cover component placement and wiring, ensuring proper operation. The keyer's compact size makes it suitable for portable or shack use, providing a reliable CW interface.

Operating the _Icom IC-746_ HF/VHF transceiver often presents specific technical questions, and this resource compiles a comprehensive Frequently Asked Questions (FAQ) document in an ASCII text format. It details common inquiries and solutions related to the rig's functionality, accessories, and potential modifications. The content is structured into distinct sections addressing general information, power supplies, antennas, microphones, keyers, amplifiers, TNC integration, and optional IF filters. The FAQ provides practical guidance on topics such as configuring the internal automatic antenna tuning unit (ATU), selecting appropriate power supplies, and understanding microphone pin-outs. It also delves into advanced subjects like computer control via CI-V, wiring for PSK31 operation, and troubleshooting common issues like low S-meter readings on 2m FM or loose tuning shafts. Specific questions cover the installation of optional IF filters, comparing Inrad versus Icom filters, and optimizing filter combinations for various modes. Furthermore, the document outlines various hardware and firmware modifications, including those for increasing monitor volume, replacing LCD driver transistors, and implementing a "poor man's TCXO." It even touches upon untested modifications, such as replacing PIN diodes in the demodulator. The FAQ also lists manual errata and discrepancies, offering a robust knowledge base for IC-746 owners seeking to optimize their station or resolve operational challenges.

BeaconSpot.uk provides an accurate, real-time picture of microwave and VHF/UHF beacons operating across Europe, alongside a worldwide listing of 6-meter beacons. The platform allows users to retrieve detailed data for individual beacons, facilitating in-depth analysis of signal characteristics and propagation paths. Interactive maps visualize beacon distribution by frequency band and display spot coverage for each station, offering a clear geographical overview of active beacons. The system integrates real-time DXCluster spots, sourced from contributors like Alain, ON4KST, and Pascal, F5LEN, and enables users to submit outgoing spots directly to the DXCluster. Beacon keepers can manage their beacon data, receive email alerts upon being spotted, and track their station's ODX (Outstanding DX) records. For every received spot, the distance to the beacon is automatically calculated and displayed, aiding propagation studies.

A synthesized 2.3 GHz Amateur Television (ATV) transmitter design, conceived by Ian G6TVJ, is presented, targeting broadcast-quality video performance on the 13cm band and extending up to 2.6 GHz. The core of the design utilizes a commercial Z-comm Voltage Controlled Oscillator (VCO) that tunes from 2.2-2.7 GHz, providing a +10 dBm output and simplifying RF alignment. This VCO's stability, originally intended for narrowband applications, readily accepts high-frequency video modulation, contributing to the transmitter's robust performance. The exciter stage, incorporating a Mini Circuits VNA 25 MMIC amplifier, boosts the signal to +16dBm, while a Plessey SP4982 prescaler divides the output frequency for the synthesizer. The synthesizer employs a Motorola MC145151 CMOS parallel IC, favored over the common Plessey SP5060 for its superior video modulation characteristics and ease of programming without microprocessors. This choice addresses issues like LF tilt and distorted field syncs often seen with SP5060 designs, particularly when operating through repeaters or over long distances. The MC145151 divides the signal further, enabling precise frequency stepping, with programming handled by EPROMs for channel selection and LED display. The loop filter network, critical for video integrity, was developed through experimentation to prevent the PLL from reacting to video modulation, ensuring a clean transmitted picture. The transmitter incorporates a Down East Microwave commercial power amplifier module, delivering approximately 1.6W output, driven by the exciter through a 3dB attenuator. Construction involves surface-mount SHF components on micro-strip lines etched onto double-sided fiberglass board, housed within a tinplate box. The design boasts no AC coupling in the video path, preserving low-frequency response, a common failing in other ATV transmitters. Performance tests with a 50Hz square wave revealed no LF distortion, and a calibrated "Pulse & Bar" signal showed a near 100% HF response, demonstrating its capability for high-quality ATV transmissions.

Brugtgrej presents a Danish online classifieds platform specifically for amateur radio operators and electronics enthusiasts. The platform facilitates the buying and selling of used equipment, including transceivers like the Icom IC-7410, various components such as X'TAL FILTER FMT-15A and TRANSISTOR 2SC3019, and accessories like Sadelta microphone capsules and SMA to SMA extenders. Users can post free advertisements for items they wish to sell or acquire, covering categories beyond amateur radio, including antique radios, military radios, and radio tubes. The site lists active advertisements, with 3136 online ads and 167 online users at the time of analysis, indicating a dynamic marketplace. It also features a forum for community interaction, discussing topics like repeater rings on 1297 MHz and FT8 activity. The platform's structure supports both 'Sælges' (for sale) and 'Købes' (wanted) listings across its various sections. Specific items observed include a Miniwatt pentode 4689, various capacitors and coils, and general electronic components, demonstrating the breadth of offerings available to the amateur radio community.

A capacitance meter kit assembled. The meter measures from 1 picofarad to 500 microfarads with an accuracy of up to 1% and less than 2%

Amateur Television (ATV) operations involve transmitting and receiving live or recorded video and audio signals over amateur radio frequencies. Unlike narrow-band modes, ATV utilizes a wider bandwidth to convey video information, often requiring specialized transceivers, antennas, and signal processing equipment. This mode allows hams to share visual content, demonstrate projects, or conduct video conferences, typically on VHF, UHF, and microwave bands due to the bandwidth requirements. The SwissATV resource focuses on the technical aspects and community engagement surrounding ATV within Switzerland. It covers topics relevant to setting up ATV stations, understanding signal propagation at higher frequencies, and participating in local ATV activities. The site serves as a central point for Swiss ATV operators to exchange knowledge and coordinate transmissions, fostering the growth of this specialized amateur radio mode.

Sixty-meter repeaters typically use a 1 MHz frequency separation between input and output, while 2-meter repeaters commonly employ a **600 kHz** split and 70-centimeter repeaters use a **5 MHz** offset. This article details the fundamental technical principles of amateur voice repeaters, explaining how they extend VHF/UHF communication range by receiving on one frequency and simultaneously retransmitting on another. It covers essential components such as receivers, transmitters, filters, and antennas, often situated on elevated locations for optimal coverage. The resource delves into the critical challenge of _desensing_—where the repeater's strong transmit signal overpowers its own receiver—and the engineering solutions employed, including antenna separation and the use of high-Q cavity filters. It also explores various control and timing systems, from basic squelch activation to more sophisticated microcontroller-based boards that manage functions like voice identification, time-out timers, and fault protection. Different access methods are discussed, including open access, toneburst, CTCSS subtone, and DTMF, each offering distinct advantages for managing repeater usage and mitigating interference. Furthermore, the article examines repeater linking, both conventional RF methods and modern internet-based solutions, highlighting how linking expands coverage and promotes activity across multiple repeaters or bands. It introduces less common repeater types such as 'parrot' repeaters, which use a single frequency and digital voice recording, and linear translators, capable of relaying multiple signals and modes simultaneously across different bands, often found in amateur satellites.

The Kentucky Contest Group (KCG) website, maintained by N4GN, serves as a hub for amateur radio operators interested in **radiosport** contesting within Kentucky and southern Indiana. It details the group's dedication to promoting contesting, offers links to KCG officers, membership rosters, and upcoming meetings, and provides access to an active KCG e-mail reflector and Facebook Group for member communication. The site also features a comprehensive list of N4GN's recommended ham radio web picks, covering various categories like contesting resources, DXing, VHF/UHF/Microwave, and propagation information. The KCG's map center coordinates were updated on May 16, 2015, shifting approximately 16.5 miles SSW to 37° 21' N, 85° 39' W. Despite acknowledging current inactivity and an outdated web presence, the group remains operational, exploring options for reorganization, including a potential merger with the Tennessee Contest Group (TCG), which was ultimately rejected. The site emphasizes that membership applications are considered from anyone with a genuine interest in contesting.

A 15-pin data switch, typically a rotary-knob type designed for DB-25 connectors, forms the basis for this microphone selector project. The resource details the conversion process, which involves replacing the original DB-25 connectors with **RJ-45** or **RJ-12** jacks to accommodate modern amateur radio microphones. It specifically addresses wiring for radios like the Icom IC-706 series (including the IC-7000 and IC-703) and Yaesu transceivers such as the FT-857, FT-897, FT-817, FT-7800, FT-7900, FT-8800, FT-8900, FTM-100, and FTM-400. The design ensures all microphone lines are switched straight through, with separate contacts for external speaker/headphone jacks, allowing simultaneous switching. The project emphasizes the practical application of switching between a headset for net control and a hand mic for rag-chewing without repeatedly plugging and unplugging cables. It highlights modifications to the original concept, such as eliminating a separate PTT jack by integrating PTT into headset cables and building the external speaker cable directly into the selector. The article provides guidance on managing the non-color-coded wiring often found in these data switches by soldering wires one by one from old to new connectors, ensuring correct pin alignment. This approach simplifies the conversion, making it accessible for hams seeking a functional and cost-effective mic switching solution.

Operating a modern amateur radio station, particularly for advanced digital modes or microwave experiments, often requires precise test and measurement equipment. This resource from NI (National Instruments), now part of Emerson, showcases a wide array of hardware and software solutions designed for demanding test objectives. Their portfolio includes modular instruments and configurable software interfaces, such as _LabVIEW_ and _TestStand_, which integrate AI assistance via _NI Nigel™ AI_ for code completion and sequence building. For those involved in RF and microwave work, the offerings extend to vector signal transceivers, RF signal generators, software-defined radios, and spectrum analyzers. These tools are crucial for characterizing antenna performance, optimizing transceiver circuits, or developing custom radio systems. The company emphasizes its 50 years of innovation, with 40 years dedicated to _LabVIEW_, highlighting a long-standing commitment to engineering solutions. The site also details products for data acquisition, electronic test, and wireless design, covering components like CompactDAQ modules for precise sensor measurements and various communication bus interfaces. Their events and perspectives sections offer insights into topics such as 5G technology and strategies for breaking out of testing silos, providing a broader context for their measurement solutions.

The San Bernardino Microwave Society, operating under the callsign _W6IFE_, serves as a significant technical hub for amateur radio operators specializing in frequencies above 1 GHz. This organization's influence extends across Southern California, providing a centralized resource for advanced RF experimentation and **regional frequency management** within the microwave spectrum. Its permanent value lies in its extensive archive of technical papers and project documentation, which are critical for operators engaged in high-frequency design and deployment. The society's infrastructure is primarily intellectual, focusing on the dissemination of specialized knowledge rather than a conventional repeater network. It offers a robust collection of technical papers from prominent members like K6PIP, K6BLG, and WA6EXV, covering topics such as Rubidium oscillator data, logging software, and filter design. This resource facilitates advanced amateur radio operations, including participation in microwave contests and the development of custom transverters for bands like 24 GHz. The site also details various member projects, such as the Owens Valley Radio Observatory Project, showcasing practical applications of **RF propagation analysis** and system integration. DXZone Focus: Microwave | Technical Papers | RF Propagation | Contest Results

Low-frequency (LF) radio time signals, operating primarily in the 40–80 kHz range, are broadcast by national physics laboratories for precise clock synchronization. Transmitters like **JJY** (40 kHz, 50 kW; 60 kHz, 50 kW), RTZ (50 kHz, 10 kW ERP), MSF (60 kHz, 15 kW ERP), WWVB (60 kHz, 50 kW ERP), RBU (66.66 kHz, 10 kW), and DCF77 (77.5 kHz, 50 kW) cover vast geographic areas, often several hundred to thousands of kilometers. LF signals offer distinct propagation advantages over higher-band transmissions such as GPS. Their long wavelengths (3–6 km) enable effective diffraction around obstacles like mountains and buildings. The ionosphere and ground act as a waveguide, eliminating the need for line-of-sight and allowing a single powerful station to cover extensive regions. Ground wave propagation minimizes ionospheric variability effects on transmission delay, and signals penetrate most building walls effectively. Robust and low-cost receivers, often priced at 20–30 USD/EUR, are widely used in radio clocks. These receivers typically comprise a tuned ferrite core antenna, a receiver IC (e.g., Atmel T4227, U4223B, MAS1016) for amplification and AM detection, and a microcontroller for decoding the time signal and phase-locking a local clock. Specific components for DCF77, MSF, and WWVB are readily available from vendors like HKW Elektronik and Ultralink.

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.

A cavity backed antenna is a practical slot antenna tipically used in microwave applications

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.

The Utah Amateur Radio Club (UARC), holding the callsign _W7SP_, provides a comprehensive resource for amateur radio operators, particularly within Utah. It details club activities such as Field Day, Winter Field Day, and annual social events like the Steak Fry and Christmas Dinner. The site also lists club resources including repeaters, _IRLP_ information, HF remotes, and a lending library. Information on becoming a ham, exam schedules, and a local repeater list are also available, catering to both new and experienced operators in the region. UARC hosts regular meetings on the second Thursday of each month, excluding July and August, at the University of Utah's Warnock Engineering Building, with presentations on topics like weather and _Skywarn_. The club publishes the monthly _Microvolt_ newsletter and maintains a YouTube channel for meeting playback. Additionally, UARC offers a Ham Hotline for questions and provides access to an "Elmer" list for mentorship, supporting the local amateur radio community.

CW decoder using a PIC microcontroller. This is a morse code decoder made using a PIC(16F88) microcontroller, this project supports displays with multiple controller chips

A data converter for the Tandy WM918 weather station. The Weather APRS data converter project aims to create an interface to interpret data from the popular Tandy WM918 weather station and format it for transmission over packet radio. The South East Radio Group in South Australia has established a network of these weather stations to provide amateurs with regularly updated weather data. However, the WM918's data output is not structured for APRS weather reporting. This project describes a solution using a PIC microcontroller to convert the WM918 data into APRS-compatible strings that can be sent as beacons or connected packets. The interface offers features like position/positionless data, connected/beacon modes, and metric/imperial units. The goal is to create an interconnected weather reporting system for amateur radio operators

Miniature PIC microcontroller based keyer kit with convenient modes. The kit includes PCB, componets, knob and ready programmed PIC microcontroller. Author make available from his web site Circuit diagram, Component layout,List of components and downloadable Software

The PicoFox is a versatile fox transmitter for 2-meter ham radio operators, built around the RP2040 microcontroller. With open-source hardware and software, it can be customized to suit your needs, from APRS to other digital modes. This fully assembled transmitter comes with a rechargeable battery and antenna, ready for use. The design allows for easy addition of features like sensors or interactivity. Modulation is handled in software for smooth FM output, with ample CPU, flash, and GPIO available. Configure your PicoFox by connecting it to a computer via USB and adjusting settings in a text file. Explore the possibilities of this innovative transmitter for your amateur radio projects.

Nuts & Volts, founded in 1980, began as an advertising-based newsprint and evolved into a leading electronics magazine. A major shift came in 1992, introducing content-rich articles, columns, and DIY projects, cementing its role for hobbyists and professionals. Reformatted in 2003 to standard magazine size, it now averages 100 full-color pages on high-quality paper. Celebrating 40 years, Nuts & Volts remains the longest-running U.S. electronics publication, with loyal readers and advertisers since the 1980s. Its diverse topics span robotics, circuit design, automation, microcontrollers, and more, appealing to all skill levels.

This project details an automatic roger beep circuit for VHF/UHF contests. Built around a Microchip PIC microcontroller, the design detects PTT (Push-To-Talk) activation and generates a brief tone upon release, mimicking a "roger beep" to signal the end of transmission. The circuit utilizes readily available components and includes downloadable resources for PCB layout and firmware.

This tutorial demonstrates how to charge laptops or tablets, like the Microsoft Surface, using off-grid 12-volt batteries typically used for ham radio gear. The guide highlights the importance of selecting a reliable USB-C PD adapter, recommending a 15V, 60W minimum with 5–20V, 3–5A capability. Featured tools include a 100W USB-C adapter and a USB multimeter for monitoring power usage. The video also explores the compact, efficient Power Queen 50Ah LiFePO4 battery for portable power solutions.

This project outlines a simple Lead Acid/SLA battery monitor, designed to alert users when battery voltage falls below 10.6V. The monitor, based on a PIC16F1827 microcontroller, checks the voltage of up to five batteries and triggers an alarm if any drop too low. The system operates in various modes, including self-test, monitoring, and alarm. This updated version improves upon the original 1999 design, offering a more modern microcontroller and extended functionality for workshop use, with minimal impact on battery charge.