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Home Brew 6 Meter Amplifier with a single 4CX250B by W4NFR

N1HFX project to improve PL tone encoder providing a more stable frequency

H.E.A.R.T. Serving Pinellas County

Icom IC-7300 english brochure, technical specifications and product description

Homebrewing a vhf bicone antenna with 8 clothes hangers and 4 feet of Sch40 non-metallic rigid conduit

Having Fun & Fellowship since 1955. The Keystone VHF Club has extensive facilities right outside Rocky Ridge Park just northeast of York, PA.

Review of the popular Heil PR-781 mic, connected to an Icom IC-7800 by k3dav

Evaluation of various microphones on-air using an Icom IC-7700 by VA7JW

For over 50 years, Communications Specialists Inc. has been a cornerstone in specialized radio frequency solutions, initially gaining prominence with their **CTCSS** and **DTMF** tone signaling products widely used in amateur radio repeaters and commercial two-way radio systems. My own experience with their tone boards in various repeater builds confirms their reliability and ease of integration, a testament to their engineering. The company's legacy in tone encoding and decoding is well-established, providing robust solutions for access control and selective calling. Beyond tone signaling, Com-Spec has diversified into niche markets, including wildlife telemetry, pet tracking collars, and specialized tracking systems for model aircraft and rocketry. Their product line features compact transmitters and receivers designed for specific tracking applications, demonstrating a commitment to precision and durability in challenging environments. While some legacy products are no longer available, Com-Spec continues to innovate, as evidenced by the new R-30M receiver, which ships within five days. This focus on specialized RF applications, from tracking Alzheimer's patients to law enforcement, highlights their unique position in the radio communications industry.

A web site for those interested in ham radio Software Defined Radio (SDR). SDR Zone provide forums, reviews and user blogs relating to any type of SDR

Featuring Eddystone, Classic British receivers (a history from 1898 - 1973) and Hubble-Bubble a personal web page

This is a neat little adapter that allows the use of a cell phone type Headset with your Amateur Radio.

DTMF Remote Controls, DTMF tone generators and broadcasting products, remote broadcasting via cell phone, cell phone mixer and remote phone keypad

Designer and supplier of tower reinforcement systems to the wireless industry.

ARRL page dedicated to AM operations

K1JJ presents a compilation of insights regarding vertical radial ground systems, specifically applied to 160m vertical arrays. The resource details 19 distinct observations and recommendations, emphasizing that ground radials primarily reduce ground losses rather than influencing pattern formation. It explains that RF current flows inefficiently through average soil, necessitating copper radials to create a low-resistance path back to the antenna base. The content suggests that **50-60 radials** are generally sufficient to achieve optimal efficiency, with diminishing returns beyond that number, and that radials should be laid on the surface for best performance. The discussion also addresses practical aspects such as wire gauge, installation techniques using 'U' shaped staples, and methods for connecting radials in multi-element arrays. It highlights the importance of radial length, stating that 1/4 wave radials are a crucial minimum, and that for 160m, radials should be at least _100 feet_ long. The resource critically examines the efficacy of elevated radials versus ground radials, noting that while a few elevated radials may suffice for VHF, HF applications, particularly on 160m, require extensive ground radial systems to efficiently collect RF currents in the near field. It also touches on the impact of radial systems on parasitic elements and the significance of symmetrical radial patterns for minimizing losses. Further practical advice includes wire type recommendations, proper soldering and weatherproofing techniques for radial connections, and considerations for integrating steel towers into the ground system. The author shares personal experience with installing 60 quarter-wave and half-wave radials under each of three in-line verticals, expressing satisfaction with the results.

Dedicated to the fine art of DXing, The DX Notebook offers a comprehensive collection of news and other items of interest to the DX community.

The Association of Carabinieri Force Amateur Radio from Italy

A CW sidetone bypass for the NESCAF audio filter, a small and low cost circuit that works great.

Electronic and RF components for the hobbyist

Helps you study for the Ham Radio & FCC GROL exams. Often times, test questions are worded in ways; that fool you. RadioTelephone Tutor drills on missed questions, till you know the answers backwards and forwards. Can take entire question pools in straight, or random order. Creates a practice test; which represents what you would be given in a real exam.

An operating guide for the com IC-2720H VHF/UHF Radio, includes Turning the power On or Off, Selecting the Output Power, Activating Memory Mode, Operating in Memory Mode

Selecting appropriate coaxial cable and wire for demanding amateur radio applications, particularly those involving high power or harsh environmental conditions, is crucial for maintaining signal integrity and operational safety. This resource details Harbour Industries' specialized offerings, which include Mil-Spec and commercial designs such as NEMA HP3/HP4 and SAE AS22759, suitable for aerospace, military, and industrial sectors. Their product line addresses the need for robust conductors capable of withstanding extreme temperatures and mechanical stress, often encountered in antenna systems or amplifier interconnections. The company highlights its AeroPOWER® Firezone M25038/3 cable, specifically engineered for high-temperature environments like aircraft engines. This particular product exemplifies their focus on solutions for critical infrastructure where reliability under adverse conditions is paramount. Such cables are relevant for hams building or maintaining stations in challenging climates or those operating high-power amplifiers where internal wiring must endure significant thermal loads. Harbour Industries also provides a range of high-performance cables designed to meet stringent specifications. Their expertise in high-temperature and high-performance cable manufacturing positions them as a supplier for specialized wiring needs beyond standard off-the-shelf options, ensuring durability and performance for advanced amateur radio setups.

Announcement of the Icom IC-7610 during the Tokyo Ham Fair, August 20 2016.

HF/50 MHz 100W All Mode Transceiver. The FT-891 provides stable 100 W (25 W AM) high power output

Official aprs.fi iOS app, immediate real-time visibility to APRS traffic near you and around the world.

Article on Yagi and Log periodic antennas by Tom, K1JJ

Amateur radio repeaters extend communication range for mobile and remote stations by retransmitting signals on a different frequency, often for emergency communications. The resource details various repeater bands, noting that 2 meters and 70 cm are primary for activity, with 10-meter repeaters offering potential national and overseas coverage. It specifies **18 channels** on 6 meters and **31 channels** on 2 meters, along with a new 70 cm offset of _7 MHz_ adopted in 2015. The content explains how repeaters can be linked via dedicated transmitters/receivers, landlines, or Internet VoIP systems like _IRLP_ and Echolink, enabling global connections. It also describes simplex gateways for multi-band operation and the use of CTCSS subaudible tones for access control and interference mitigation. The document highlights specialized repeaters for modes beyond voice, such as SSTV and ATV, particularly on 70cm and higher bands. Operational guidelines for efficient and courteous repeater use are referenced, along with links to Australian repeater listings and band plans.

Documentary and seminar videos for and about Amateur Radio, on DVD and online. Some make excellent club meeting programs.

Baofeng UV-5R dual band handheld transceiver, features, pictures, movies, links and manual.

Decode DTMF from your iPhone. Hold your smartphone close to a DTMF source and this app will decode the numbers being dialled.

Show CQ and ITU Zone in an interactive clickable map based on google maps. Additional locator tool tip can be displayed by clicking on points, and a search function it is also available to locate addresses, and locators.

Schematic diagram for a high voltage power supply by W4NFR

The Kenwood MC60A with preamp, suffers from RF feedback, a search on the web reveals the extent of the problem. This document explain how to fix this problem.

A voice keyer completely integrated into the standard Yaesu MH-31 amateur radio microphone

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.

Mic online calculator , Microphone Dynamic Range Calculator, Microphone Sensitivity Calculator

ASAP Semiconductor is a premier source for all long lead-time, hard to find, and obsolete components.

Maintaining vintage Eddystone receivers often presents unique challenges, as detailed by Victor Jenkins in his refurbishment of an EA12, where his deep understanding of RF circuits ensures optimal performance for daily shortwave listening. Similarly, Gerry O’Hara VE7GUH, a prolific contributor to the EUG website and a trustee, meticulously documented his restoration of an Eddystone S830/2, even addressing an unusual instability issue with a follow-up postscript article and YouTube videos demonstrating the fix. His work, along with numerous other articles on the "Restorations" page, showcases a master's approach to bringing vintage sets back to factory specifications or better. Beyond technical restorations, the EUG also shares compelling historical narratives. One such story recounts the discovery of a long-lost 78rpm recording featuring Eddystone Radio Ltd.'s founder, George Stratton Laughton, and other key figures discussing the company's wartime and post-war contributions to shortwave communications. This six-minute BBC production, transcribed into an MP3 file by Peter Carney, offers a rare auditory glimpse into the company's legacy, highlighting its role in supplying equipment to police, ministries, and expatriate British workers. The community aspect thrives through shared experiences, like Roger Trickett's anecdote about his Eddystone EC10, which has been continuously powered for 50 of its 54 years, traveling across continents and enduring various modifications. Another intriguing account from Roy GM4VKI details the "S640 Identity Crisis," where a seemingly standard S640 receiver turned out to be a masterfully engineered 80/20-meter SSB transceiver built into the original chassis by GI3ZX, showcasing incredible ingenuity from a bygone era of amateur radio.

AM and vintage radio forum

A Kenwood TM-D710A microphone (Model MC-59) is producing crackling and intermittent, poor audio so John took a peak inside to have a look around.

Traveling Wave Tubes , Conventional Traveling Wave Tubes, Microwave Power Modules manufacturer

Serving Akron, Ohio, Summit County and the surrounding area since 1981

An improved version of the audio interface commonly used to connect a computer soundcard to a transceiver\'s receive and transmit audio circuits

VB2C VC2C VB2V VB2R

YRC the Yellowstone amateur radio club

Electronics components, rf connectors worldwide dealer

New Club Site For Maidstone YMCA ARS

A mailing list in spanish to exchange shortwave dx i nformations

Weak Signal Audio 160m, choosing a headphone for weak signals reception