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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.

The Premier MidWest DX Convention, Illinois.

MacOSX real-time precision signal / waveform generator. Uses native Mac sound Out capabilities.

Aanarad Trabzon department turkey

This is not a sophisticated automatic keyer but it is lot QRP to build and to have fun operatin

All about dipole antenna construction

Shelby amateur radio club's VHF emergency net is open to all within the repeater's coverage area. 146.880 and 147.345 are the repeater frequencies. Shelby Radio Club is the sponsor of the Shelby hamfest.

Features, functions, a howto and opinions by Jason Buchanan - N1SU

Fixing the IC-7000 noisy audio that can occur when IC-7000 audio output is connected to Hi-Fi earphones or external speaker.

Hamradio page with pictures and links

The AB2RA bowtie 80 meter antenna includes also a 40 meter dipole

Cliped tools items for electronics

W5UXH version of OZ1JHM Morse Code decoder project

Operating magnetic loop antennas requires careful consideration of RF safety, particularly regarding near-field magnetic field intensity. This resource presents calculations for magnetic field strength (H-field) at various distances from a magnetic loop, emphasizing that the H-field is significantly higher than the E-field in the near-field region due to the inductive nature of the radiating element. It provides specific formulas and examples for determining safe operating distances based on power levels and loop dimensions, crucial for compliance with RF exposure limits. The analysis compares calculated H-field values against FCC and ICNIRP maximum permissible exposure (MPE) limits for controlled and uncontrolled environments. It demonstrates that even at QRP power levels (e.g., 5W), the H-field can exceed MPE limits within a few feet of the antenna, necessitating greater separation distances than often assumed for electric field considerations. The practical application of these calculations helps amateur radio operators configure their stations to ensure personnel safety and regulatory compliance when deploying compact, high-Q magnetic loop antennas.

HSCW/WSJT meteorscatter/path simulator a first attempt at trying to model meteorscatter events and simulate their transmission characteristics

Chilean amateur radio club

Lithium Lead NiMH NiCad Ion batteries

Hose Company 1 East Rockaway Fire Department Official Page. Scanning FDNY & East Rockaway Fire

This site is dedicated to the repair, restoration, preservation and sale of old collectable radios, both bakelite and wood.

Guide to soldering an desoldering

Yaesu transceiver vx-170 water proof test

A family of small size QRP SSB transceivers for the 15 MHz. Includes a cigarette pocket size QRP transceiver and a larger shirt-pocket transceiver.

Test equipment and tools

Welcome to the Web page of Alpha Yankee SSTV by 14AY03 and 14AY04,many pictures,links of pages and softwares...

The NIDXA is an active DX club affiliated with the ARRL. NIDXA runs the W9 Incoming QSL bureau, a DX Packet Cluster, and the world famous W9DXCC convention.

Spipral antenna principle by a concept of Bill Petlowany, K6NO. Tak Antennas are based on this principle, using spirals as dipole linear wires.

The vertical Double-Zepp 2x7 m is a very simple, effective 8-Band-antenna. The end of the Dipol must be 5-10 m above the ground

iPhone Software to practice taking your Ham Radio Exam

MP3 and Wav files of some stations recorded on HF anc VHF bands by K9MU

Sunstone.com PCB123 PCB download software. Review Sunstone quality pcb design software. Free PCB software download for all of your business needs.

TNC-Pi is a special version of TNC-X designed to interface directly with the Raspberry Pi computer. It can connect to the Pi either via the Pi serial port, or via the I2C protocol.

Amateur Radio in the Blackstone Valley area

Constructing a Compact Low Cost Sprinkler Valve Antenna Launcher

This is another alternative home-brew center connector for a dipole. The parts used are common PVC accesories found at the home supply store.

A project to homebrew a Lightning Detector

Rail Radio Communication Feeds broadcasted from all over the United States and beyond.

ON6MU Low Power amplifier

MARC is dedicated to providing safe and reliable two-way radio communications for selected charity events in their respective regions

Modifications for the Kenwood TS-870S

Using a PC with soundcard as a VLF receiver, how to use your PC as a receiver for narrow-band signals in the VLF radio spectrum by DL4YHF

Testing performances of indoor antenna. A comparison of a magnetic loop antenna vs a classic wire dipole done using wsprlite on 30 meters band.

Hi-Z Antennas offers specialized high-impedance receiving systems, primarily focusing on phased vertical arrays for HF reception. Their product line includes preamplifiers designed for shortened vertical antennas, featuring optimized 15dB gain and array-matched characteristics. These components are engineered to enhance weak signal reception and improve signal-to-noise ratio across the HF spectrum. The company provides controllers for managing multiple vertical elements in a phased array configuration, enabling directional reception patterns. These systems are particularly effective for mitigating local noise and interference, a common challenge in urban and suburban operating environments. Specific offerings include solutions for 160-meter and 80-meter bands, addressing the unique requirements of low-band DXing. Technical details often reference components like the 2N3866 transistor in preamp designs and discuss concepts such as out-of-band attenuation. The focus remains on optimizing receiving antenna performance through impedance matching and active amplification, rather than transmit capabilities.

A workbench instrument capable of testing transistors, diodes, FETs, usefull constructing QRP circuitry.

The Voice of Idaho Amateur Radio Club Website. News and information from Treasure Valley and surrounding area

How to repair a FT1000MP front end, damaged from too much neighbouring RF during contesting

Long Beach Los Angeles county live scanner feed

Loop Antenna Basics and Regulatory Compliance for Short-Range Radio

Small, but growing, group of amateur radio enthusiasts, most of whom are within 90 miles (and more) of Atlanta

Over 45 years of dedicated work by Robert Sherwood, NC0B, culminated in a wealth of technical insights, particularly concerning **receiver performance** and the intricacies of transceiver design. The site provides access to numerous presentations from events like Dayton Contest University and W4DXCC, covering topics such as optimizing rig performance, the evolution of lab testing, and the impact of roofing filters on transmitted IMD and receiver characteristics. These resources offer detailed analyses and practical advice for serious operators and contesters. While product manufacturing, including the SE-3 MK IV synchronous detector and various Drake R-4C accessories like roofing filters and cooling kits, has ceased, the legacy of technical documentation remains. The site details specific products like the Icom IC-781 and R-9000, and offers insights into 455 kHz mechanical and crystal filters, along with DSP protection strategies. Crucially, the site features extensive receiver test data, allowing radio amateurs to compare the performance of various transceivers. This data, often presented in white papers and slide shows, includes detailed measurements and explanations of key performance metrics, serving as a valuable reference for understanding and selecting high-performance HF gear.

Articles about Amateur Radio, own writings and translations: history, DXpeditions, contesting and DXing ethics, Codes of Conduct, Suggestions for Pile-ups, Suggestions for Contesters, the most wanted DXCC entities.