Search results

The RFzero is a multi function signal platform developed for radio amateurs who wants to extend the Arduino skills in combination with RF. The RFzero board is largely compatible with the Arduino Zero and Arduino M0 boards, however, it has been carefully designed for flexible use in RF applications and with attention to the frequency spectrum and stability performance.

The Cheshire County DX Amateur Radio Club - or CCDX ARC - Has been around for well over a decade. The longest running club ever in this area.

Lake county races/ares, volunteer auxillary communications group working under lake county emergency management agency. offical skywarn site for lake county. VE testing and radio clases offered. not-for profit 501(c)3

Blog site for various home brew projects including antennas, power dividers etc

Spanish ham radio chat

CRAM - Club Centro Radioaficionados Montevideo, CX1CCC, Montevideo, Uruguay

Havering and district Amateur radio club based in Hornchurch, Essex

Demonstrates the fundamental principles for connecting a personal computer to a ham radio transceiver, specifically for utilizing sound card-based digital mode software like those in the MM Hamsoft suite. It details the basic hardware setup, emphasizing the use of shielded leads and proper audio routing from the radio's output to the sound card's input, and from the sound card's output to the radio's microphone or data input. The resource highlights the critical need for transmit attenuation, suggesting a 100:1 voltage divider to prevent overdriving the transmitter's audio stage, and mentions the optional addition of ferrite beads and decoupling capacitors for RFI mitigation. The guide also points to external resources for more detailed pin-outs and interface schematics, such as a specific QSL.net page, and recommends consulting the help files within MM Hamsoft programs for interfacing specifics. It underscores that while the process is straightforward, understanding the audio level management and proper cabling is key to successful operation. The author, VE5KC, provides practical advice drawn from common issues encountered by operators setting up digital mode stations.

South Bay Amateur Radio Club

A cavity filter, often a critical component in _duplexer_ designs, functions as a sharply tuned resonant circuit, allowing only specific frequencies to pass while attenuating others. These filters are essential for maintaining signal integrity in environments where multiple transmitters and receivers operate simultaneously on closely spaced frequencies, such as in repeater stations. The article details how these filters, sometimes referred to as _notch filters_, achieve high Q factors, which are crucial for their performance. Understanding the principles of cavity filters is fundamental for any amateur radio operator involved in repeater operation or designing custom RF front-ends. The discussion covers the basic circuitry and operational characteristics that enable these devices to provide significant isolation, often achieving **-80 dB** or more between transmit and receive paths. This level of isolation is vital for preventing receiver desensitization and intermodulation distortion. Properly tuned cavity filters ensure that a repeater can transmit and receive simultaneously on different frequencies without self-interference, a common challenge in VHF/UHF operations.

Antenna Authority Inc. offers a wide assortment of directional, wideband antennas and other equipment specifically engineered for radio direction finding (DFing) and geolocation applications. Their product line includes _log periodic_, _cavity-backed spirals_, and _Yagi_ antennas, alongside covert antenna solutions for various operational requirements. The company emphasizes its expertise in designing and manufacturing specialized antennas for both overt and covert operations. Beyond standard offerings, Antenna Authority Inc. provides custom design services to meet specific client needs, focusing on tailored RF directional products. Their capabilities extend to developing antennas for vehicles and optimizing their operational performance in diverse scenarios. The firm is located at 3381 W. County Line Road, Douglasville, Ga. 30135-1145. Ferrel Bentley is associated with Antenna Authority Inc., which has been operating since at least 2005, as indicated by the copyright notice.

Ham-Spirit.de amateur radio classifieds from germany

The Radio Amateur Megacycle Society

1500 watts PEP SSB is the power handling capability of the MFJ-989C HF Antenna Tuner, a popular choice among amateur radio operators. Users have shared a wide range of experiences, with some praising its durability and performance over decades of use, while others criticize its build quality and accuracy. The tuner features a built-in dummy load, SWR-wattmeter, and a balun for balanced line feeders, making it versatile for various antenna setups. However, discrepancies in RF power readings and SWR measurements have been noted, with some users finding the dual scale meter to be off by about 20% compared to a Bird wattmeter. Long-term users report that the MFJ-989C performs well with proper antenna setups, but caution against tuning at high power without initial adjustments at lower power levels. Some have experienced issues such as arcing when exceeding 400 watts, while others have had no problems even at higher power levels. The roller inductor and capacitors are functional, though some users have had to perform maintenance like tightening screws or cleaning components to ensure reliable operation. Despite mixed reviews, the MFJ-989C remains in production, suggesting continued demand. It's a tuner that requires careful handling and possibly some DIY fixes to achieve optimal performance.

This document has been produced by examining the data going into and coming out of the TH-D7 HT from Kenwood.

The CQ World Wide DX Contest records document top scores, with the Multi-Multi SSB category showing CN8WW achieving **78,170,508 points** in 2000. These records span from 1948 to 2025, categorizing results by region, operating class (e.g., Single Operator High Power, Low Power, QRP, Assisted), and specific bands like 10M, 15M, 20M, 40M, 80M, and 160M. For instance, EF8R (E77DX) holds the All-Band High Power SSB record with **25,747,775 points** in 2025. Each entry includes the callsign (with operator callsign in parentheses for guest ops), year of operation, and total score. The _CQ WW DX Contest_ also features records for the RTTY and VHF contests, alongside the main SSB and CW categories. QRP records demonstrate significant achievements, such as P40W (W2GD) with 5,097,780 points in the All-Band SSB QRP category in 2000. Multi-Two and Multi-Single categories are also detailed, providing a comprehensive overview of competitive performance.

Review of the X1M HF QRP trasceiver by VE3FAL

Ham radio site with personal info, search facilities and some links pages

Low Country Amateur Radio Club Summerville, South Carolina 147.060+ / 147.030

News/Projects for Amateur Radio

BCHF 14.316 MHz Broadcasters HF NET where radio/tv broadcasters-engineers meet 2300 UTC Sunday's

The first interactive map of amateur radio repeaters and more updated in REAL TIME.

Oost Vlaamse Radio Club Belgium

An interesting article on pedestrian portable HF DXing

Jules Verne's "Around the World in 80 days" is old fashion way. Be an amateur radio I'll bet you'll rounding the world just on a flash!

Diamond Antenna CP22E VHF base station antenna review. This antenna has a remarkable design achieving 5 dBi directivity in a slim low-profile design.

DMR Contact Manager is a Free software package designed to make it easy to maintain channel, zone, contact and call group information in these radios. It is fully compatible with the Ham-Digital and RadioID database systems and allows instant codeplug updates from a wide variety of sources. DMR Contact Manager is designed for use with Connect Systems CS700/CS701/CS750/CS800/CS801/CS800D radios, as well as the Tytera MD-380/390/390GPS, TYT MD2017/MD9600, AnyTone AT-D868UV and AT-D858, Retevis RT3, and similar radios that use the RDT/RDB file formats.

Presentation station,contest,portable,techniques,bidouilles,balises,relais,radioamateurs,swl,technique,infos,reglementation

Amateur radio Quad Antennas manufacturer based in Italy produce HF and VHF Quad antennas, and spare parts.

Ham radio classifieds from holland

A complete guide for newcomers edited by the Radio Amateur Society of Australia Inc. This free PDF includes several basic articles for new hams, with particular reference to Australian regulations, but is however a good guide for those who are aproaching the hobby worldwide.

All ham radio inforamtion needed from M?xico.

Yahoo Group dedicated to the Amateur Radio Community, not the Commercial Sector.

Italian prefix maps and band plans, includes links to antenna plans and many ham radio resources.

A great amateur radio shack desk done with a second hand solid core door, measuring 32 inches wide by 80 inches long.

The Utility DXers Forum (UDXF) provides a centralized platform for exchanging news and information concerning utility radio stations and signals operating within the 0 to 30 MHz spectrum. It specifically excludes broadcasting, pirate, and amateur radio transmissions, concentrating instead on a diverse array of other signals. The resource details the types of stations covered, including maritime coastal and ship stations, aeronautical ground and aircraft communications (voice, HFDL, Selcalls, Volmet), military operations, various beacons (NDB, driftnet, propagation, pirate, high-frequency), fax transmissions, numbers stations, diplomatic communications, clandestines, and other unusual signals. Further content addresses radar systems such as Over-the-Horizon, Ocean Wave, and CODAR, alongside ionosondes, chirpsounders, ALE-systems, Selcall-systems, and tone calls. Experimental stations and standard frequency and time stations are also within its scope. The forum also acknowledges utility radio-related amateur events like the International Lighthouse Weekend and Night of Nights, providing a broader context for listeners. The site offers sections for modes, hardware, software, a utility radio archive, digital BC & HF conditions, and a utility radio club archive, along with QSLs and pennants.

Details on projects by WA3TFS published in QST magazine over the past few years. Includes an online shop with several ham radio kits, circuit boards, simple SDR transceivers

Distributed Antenna Systems technology used for gaining better coverage and using a lower power.

Online calculator for J-Pole antennas. The J-pole antenna consists of a short and a long vertical pole with a feed point near the bottom. The antenna looks like the letter J, hence the name J-pole antenna.

International supplier of radio astronomy products

On March 27, 2017, the FCC adopted final rules for the USA 630-meter band, detailed in Report and Order FCC 17-33, which required PLC coordination with the Utilities Telecom Council before amateur operations could commence. This resource documents the WD2XSH experimental group's activities, including authorized stations, band plans, and frequency assignments within the 465-515 KHz range, with many stations operating between 495-499 KHz and 501-510 KHz. The site also highlights the WRC-12 decision on February 14, 2012, which granted a new **7-kilohertz-wide** secondary allocation between _472-479 kHz_ for the Amateur Radio Service worldwide. The group's efforts included operating with a maximum ERP of **20 Watts** across 45 stations in the continental USA, Alaska, and Hawaii, using emission modes such as CW, PSK-31, FSK-31, and MSK-31. The site provides links to download FCC 17-33 in PDF and DOCx formats, and offers a station location map, a list of stations by callsign and frequency, and an archive of news updates. Reception reports for any 600-meter station are encouraged to help the amateur radio community understand propagation and repeatability on this challenging band.

Adding a Software Defined Radio to an SO2R station

Topeka, Kansas

Sioux empire amateur radio club - wØzwy - sioux falls, south dakota

The Denton County Amateur Radio Association is located in Denton, Texas

China

Examines Radio Frequency Systems (RFS), a manufacturer specializing in high-performance cable solutions for diverse communication infrastructures. The company, with over 120 years of heritage, focuses on designing and producing robust, long-life connectivity systems, including _low loss foam dielectric RF cable_ and _premium radiating cable_. RFS's product range supports critical applications in cellular networks, microwave antenna systems, and specialized installations within buildings and tunnels. The resource highlights RFS's commitment to innovation, addressing emerging industry standards like _FRMCS_ for railway communication and advanced fiber solutions for data centers. It also details the company's manufacturing capabilities in Hannover, Germany, emphasizing the quality and reliability associated with _Made in Germany_ products. The content covers various connectivity landscapes, from urban solutions for connected cities to private 5G credentials and future plans. Specific product categories include _fiber, power & hybrid cable_, and _low loss high power air dielectric RF cable_, showcasing their broad portfolio for complex RF environments.

A simple freeware scanner program for the Kachina DSP505. The software does NOT control the radio thru the interface port - it works in conjuction with the Kachina control software using the file interface