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Roger, G3XBM, shares his extensive experience in **QRP** (low-power) amateur radio operation, detailing various aspects of transmitting with minimal power. The resource provides insights into VLF (Very Low Frequency) reception techniques and the construction of simple **crystal radio sets**, reflecting a foundational approach to radio experimentation. It includes links to external resources covering QRP clubs, online receivers, manufacturers, and technical references, offering a curated collection for enthusiasts. His page serves as a hub for those interested in the challenges and rewards of QRP, often comparing the efficacy of different low-power setups. The practical application extends to understanding basic radio principles through hands-on projects like crystal sets, which G3XBM has explored. The collected links provide a starting point for further research into specific QRP equipment or operating practices, drawing on G3XBM's long-standing engagement with the QRP community.

Download free skins for PowerSDR, a SDR client appliction. Skins provided by W1AEX

Web based VHF-UHF RF planning powered by SPLAT! and Google Maps. Access via website, Android App or dynamic Google Earth interface.

WI ham club partecipate in Field Day, sponsers an annual Swapfest held in August, and provides various repeaters.

The _National Contest Journal_ (NCJ) serves as a dedicated resource for amateur radio contesters, providing in-depth articles, operational strategies, and technical insights. Published bimonthly by the ARRL, it covers a wide array of contesting topics, including antenna systems, station optimization, operating techniques, and rule interpretations for major events like the NA Sprint and various QSO Parties. The journal aims to enhance the competitive edge of participants across all skill levels, from casual operators to serious multi-operator teams, by sharing experiences and data from high-scoring stations. NCJ content frequently includes detailed analyses of contest results, offering breakdowns of scores, participant statistics, and comparisons of operating strategies. Readers can find practical advice on improving their contest performance, such as optimizing logging software usage or maximizing **run rates**. The journal also features columns on specific contest modes like RTTY and provides updates on rule changes and upcoming events, helping contesters prepare for future competitions and achieve better results, often leading to **top 10** finishes in their respective categories.

Cobalt Pet is a weblog focusing on shortwave radio. It features shortwave reception reports, product reviews, photos, listening tips, and links. International broadcasters and amateur / ham radio operators are monitored and discussed.

Homebrewed handheld RF powermeters for various sensors by DL5NEG

The lists are the most comprehensive compilations of frequencies for the Greater Cleveland area

A 4 AMP / 18V regulated power supply schematic, designed by _ON6MU_, provides a detailed circuit diagram for constructing a robust power source. The design focuses on delivering a stable 18-volt output at up to 4 amperes, crucial for powering various amateur radio equipment. This resource presents a clear visual representation of component interconnections, including rectifiers, filter capacitors, and voltage regulation stages, essential for DIY enthusiasts building their shack infrastructure. The schematic's clarity facilitates understanding the power flow and component roles within the circuit. This circuit design offers a practical solution for hams needing a reliable 18V supply, potentially useful for driving specific transceivers, amplifiers, or accessory circuits. While specific performance measurements or comparisons to other designs are not detailed, the schematic itself serves as a foundational blueprint. Builders can adapt or modify the _power supply_ to suit their particular needs, such as integrating overcurrent protection or fine-tuning the output voltage with adjustable regulators. The straightforward presentation makes it accessible for those with basic electronics knowledge to assemble and troubleshoot.

A novel approach to contruction of a gamma match.

6-Meter Solid-State 100W Linear Amplifier complete documentation German and English

Elongated Terminated Loops, usage and details by K9AY Lewallen

Presents a curated collection of newsletters dedicated to _Earth-Moon-Earth_ (EME) communications, primarily focusing on the 432 MHz band and higher microwave frequencies. The resource details various EME DX experiences and news contributions from operators like K2UYH (W6/PA0ZN), offering insights into successful moonbounce contacts and operational strategies. It serves as an archive of specialized content for those engaged in or interested in extreme weak-signal propagation via the moon. The newsletters provide practical information on achieving EME contacts, often including details on station setups, antenna arrays, and signal reports from challenging DX. For instance, operators might report achieving contacts over **750,000 km** round trip, demonstrating the feasibility of long-distance communication on UHF and microwave bands. The content differentiates itself by concentrating on the unique technical and operational aspects of EME, which contrasts significantly with terrestrial DXing, providing a specialized knowledge base for advanced amateur radio operators.

A good overview article on power supplies by Karl Shoemaker AK2O of the Spokane Repeater Group

C & Ku band satellite equipment - LNBs & LNBFs - MPEG-2 dvb receivers - dishes & More.

Codec2 is an open source low bit rate speech codec designed for communications quality speech at around 2400 bit/s. Applications include low bandwidth HF/VHF digital radio.

Blackford and surrounding counties Police, Fire, EMS, and EMA.

Configurations of the vertical antenna arrays used at 6Y2A

Solving Ignition Noise RFI article. Help on removing noise interfences caused by ignition

Pirate radio recordings, addresses, links and QSLs

Coupling the Duracell DR36 battery to the FT 817 The main advantages on this system are, the weight, size, quick battery changing and no stress to the FT 817 power connector

Intended for portable long-term usage and also good for Field Day Events article by By Steve KB1DIG & Kim KB1GTR

A simple simple sweep generator circuit design where the sawtooth is generated by the PNP transistor and a 555

Live DX spots are presented through a _web cluster_ interface, utilizing both a world map and a Google Maps display for visualizing amateur radio propagation. The system provides real-time spotting data, enabling operators to track active stations globally. Users can observe current band conditions and station activity, which is crucial for optimizing contact strategies across various amateur bands. The platform's utility extends to contest operations and general DXing, offering a visual representation of where stations are being heard. While the primary function is DX spotting, the site also includes technical articles, such as instructions for interlocking two Flex Radios for single-transmitter compliance in contests, and a guide for constructing a simple **5KW** 1:1 balun for **160m/80m** dipoles using RG400 cable. This combination of live data and practical technical content supports both operational awareness and station improvement.

This is a "techie" site, dedicated to presenting service manuals, parts lists, schematic diagrams and other information of value to restorers and technicians who try to keep these radios working

The following very comprehensive list was produced by G6DOF and has been extracted from the amateur radio packet network

Solartech Power Inc. manufactures, distributes and sells high efficiency solar panels and wind power turbines.

What is an EWE Antenna, comparisons, performance and homebrew plan

The ITU, headquartered in Geneva, Switzerland is an international organization within which governments and the private sector coordinate global telecom networks and services.

Audio files to help identify rf noise (rfi). Identify the RFI that interferes with your reception. RFI Noise identification.

Professional & amateur observations

UK dealer for pmr audio accessories, batteries and cases, audio accessories and airwave tetra products

Scanning railroad communications in the toronto area

Listen to the Baltimore City Police radio feed, carries all of the police districts in Baltimore City (BPD)

Comprehensive information page about bi-directional Beverages, including applications, construction details, and tips.

Two meter band antenna

Approximately 1,500 unique DX spots are typically visible on the _ODXC Web Monitor_ at any given time, providing real-time intelligence for amateur radio operators seeking DX contacts. This service aggregates spotting data from the _RW3XA-8 Obninsk DX Cluster_ node, presenting it through a straightforward web interface. Users can monitor current activity across various HF bands, identifying stations calling CQ DX or reporting rare entities. The platform supports both traditional telnet access for those using dedicated cluster clients and a Java-based web interface, catering to different operational preferences. It serves as a practical tool for contesters and DXers to track propagation, identify active stations, and plan their operating strategies. The cluster data includes callsigns, frequencies, modes, and spotter information, crucial for effective DX hunting. Integration with other spotting networks like _RBN_ and _PSK Reporter_ enhances its utility.

Interesting article on how build your own field day antenna

How track and solve electrical interference from you computer

VE3CVG 222 MHz (1.25m) 6 element plumber's delight yagi antenna

Sherwood Engineering Inc. (SEI) offers a repository of technical presentations and white papers focused on optimizing amateur radio transceiver and receiver performance. Content includes detailed analyses of _roofing filters_, transmitted IMD, and receiver characteristics, with specific discussions on products like the Drake R-4C and Icom IC-781. Presentations from events such as Dayton Contest University (2008-2014) cover topics like "How To Optimize Rig Performance," "Transceiver Performance: 10 Years of Change," and "Choosing a Transceiver: Far from Simple." Additional white papers address HF mobile antenna efficiency, ground screen alternatives to buried radial systems, and common receiver problems with solutions. The site also provides historical product information for items like the SE-3 MK IV synchronous AM detector and various 455 kHz mechanical and crystal filters, though many products are no longer in production. Receiver test data and alignment tips for the R-4C are also available, offering insights into rig modifications and performance enhancements.

Article on how use Genesys sowftware to design RF power amplifiers

A moon tracking software capable to drive the rotation of your antennas in azimuth and elevation

Jason is a weaksignal communication program, especially tailored for LF work.

5 webcams from ATV-Relais DB0MIN

Chino, Montclair, Ontario, Rancho Cucamonga, Upland San Bernardino County police radio scanner

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.

Converting a PC Switching Power Supply to 13.5V by AA3SJ

This is the 195-foot tall rotating Rohn 55G tower at W8JI with yagis for 40 20 15 and 6 meter bands.

This calculator is designed to give the vertical length of a quarter-wave ground plane antenna, and the length of each of the four radials for the selected frequency you have entered