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An article edited and published by Michael Mandeville on correlation of sunspot peaks and global events, like recessions or human conflicts. This document include solar cycle charts since Solar Cycle 1749-1751

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.

Main High Frequency Antennas from the 2009 LARC FARL Field Day, Ford Amateur Radio League. A document comparing antenna performances and flexibility among a G5RV an Carolina Windom and a Cushcraft R7 vertical antenna.

If you like building good antennas, this one is for you. The J-pole is a slim, omnidirectional, half-wave antenna fed at the end through a quarter-wave shorted transmission line. Its predecessor is the famous Zepp antenna developed for the Zeppelin airship.

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

Amateur radio map of Italy with WW locators, provinces abbreviations and Call sign Prefixes, in a A3 size PDF file free to download, made available by IU3KJL Davide

Using Chokes and Traps: how to make them, how they work.

Dubus article about DL6WU long yagi antennas for 23 cm band Article is both in german and english. Yagi antennas are valid alternative to dishes for troposcatter operations. This article explains design and mechanical data for 1296 MHz Yagi Antennas

Read more about the purpose, policies, and procedures of The National Traffic System in this 48 pages PDF File

This EXCEL Program Worksheet calculates the common-mode impedance of a 1:1 Guanella (current) balun which is placed at the feed point of a balanced antenna system fed via coax.

A low cost, low power microwave transverter so that you can operate easily on 70cm band even with a HF or VHF transceiver

In this article, author examine stresses placed on common-mode chokes (aka baluns) as hams use/abuse them, examine the efficiency of simple dipole multi- band antennas and their feed systems. Stressing a Balun.

This article is about a home made project of a whip antenna for 2 meters band. Includes lenght of whip for all frequencies from 140 MHz to 151 MHz both in mm and inches

An inverted V Dipole antenna for HF bands, working on 10 20 40 and 80 meters band. PDF Presentation

The ICOM IC-7610 SDR HF/50MHz Transceiver Basic Manual in English PDF File 13 MB

Roach pole vertical antenna for 40 and 30 meters band featuring good performance on short skips contacts compared to wire dipole

The N1HFX thermal cooling fan controller project details a practical circuit designed to manage cooling fan operation based on temperature, a common requirement for high-power amateur radio equipment. This build utilizes a **LM34** temperature sensor, providing a linear voltage output directly proportional to Fahrenheit degrees, simplifying the control logic. The circuit's core functionality involves a comparator that activates the fan when a preset temperature threshold is exceeded, ensuring efficient cooling and reducing unnecessary fan noise. This controller is particularly useful for amplifiers, power supplies, or transceivers that generate significant heat during operation. The design incorporates a _TIP120 Darlington transistor_ to drive the fan, capable of handling up to 5 amps, making it suitable for a range of fan sizes and current requirements. Field results indicate stable temperature regulation, preventing thermal runaway in enclosed environments. Construction involves readily available components, making it an accessible project for hams looking to optimize their station's thermal management.

Adapted from a similar project by NA4IT. Made with one quarter wave 2 meter radiating element pointing upward and it is surrounded by four 70 cm elements.

Presents the Bullitt Amateur Radio Society (BARS), KY4KY, detailing its organizational structure, meeting schedule, and operational activities. The resource outlines regular club meetings held on the second Tuesday of each month at Pioneer Village City Hall, providing specific dates for upcoming gatherings in March and April 2026. It also highlights the weekly BARS 2-Meter Net operating on 146.70 MHz, noting its suspension on meeting nights, and provides information on the club's participation in W1AW/4 operations for Kentucky, including specific UTC time slots for March 2026 and a contact for coordination. Details for becoming a member, contributing to the repeater fund, and joining the email list are available through quick links. The resource also offers practical information for prospective hams, such as exam test locations and BARS dues. It includes directions to the meeting location at Becknell Hall (Pioneer Village City Hall) from I-265 and Preston Highway, specifying the address as 4700 Summitt Drive, and mentions the club's presence on Facebook for activity updates.

A Quick start guide to NPR New Packet Radio on 70 cm band by the NPR author Guillaume F4HDK. This presentation introducte basic concepts of this niew digital protocol, and guide the user to the first modem configuration both of client and master modems. Includes a final recap of commands.

Demonstrates the community-driven mission of the McKinney Amateur Radio Club (MARC), a North Texas organization dedicated to advancing amateur radio. The club actively promotes continuous learning, encouraging technical innovation among its members, and provides avenues for public service engagement, skill enhancement, and global connectivity with fellow operators. MARC hosts weekly breakfast discussions every Saturday at 7:30 AM at IHOP in McKinney, Texas, covering diverse topics and offering a Q&A forum. The club emphasizes emergency communication preparedness, antenna design and tuning, and the science of global radio wave propagation, crucial for clear amateur radio contacts. Furthermore, MARC explores modern radio technologies, including digital modes and _Software-Defined Radio_ (SDR), blending traditional amateur radio with cutting-edge advancements. The club also facilitates license testing sessions, hands-on training, and participates in events like _Field Day_ to hone emergency communication skills.

Supporting wire antennas with squid poles

A classic document originally presented in Proceedings of the Institute of Radio Engineers in 1937 and is, still today, the standard referenced by the FCC, text books and many amateur radio publications.

Utility-Driven Tradeoff Analysis, if you want to geto on the microwave bands , you will have to choose the proper antenna for your operating conditions. How to decide is not always easy, and you may also decide to build your own antenna.

A light and sturdy Quad for 10 and 15 meters. Basic Quad antenna design considerations. Building and assembling a dual band HF QUAD antenna, designing and joining cross-arms and boom, assembling spreader and element wire installation notes. QST article.

This resource provides a discussion group platform for amateur radio operators interested in APRS within Argentina. It facilitates technical discussions, sharing of operational experiences, and coordination among users of the Automatic Packet Reporting System in the region. The group serves as a central point for exchanging information on local digipeater networks, IGate deployments, and mobile tracking applications, covering both hardware and software aspects relevant to APRS implementation. The forum enables members to post questions, offer solutions, and disseminate news related to APRS activities specific to Argentina, fostering a community-driven approach to problem-solving and knowledge transfer. It supports the collaborative development and maintenance of the APRS infrastructure, allowing for real-time interaction on topics such as frequency usage, network topology, and integration with other amateur radio services.

A very well done presentation about End-Fed Half-Wave antennas. This PDF document contains a summary of experiences in how to build custom EFHW antennas. Includes an interesting comparison table of UnUn configurations with recommended toroids, Wire size, turns and capacitors. An useful recap on common errors in building homebrew EFHW Ununs completes the document.

Building an amateur station for competitive radiosport involves a number of critical steps, regardless of the band or bands you focus on. These include, but are certainly not limited to: Station layout, Equipment interconnection and switching, Inter-station interference, Antenna selection. Radio interface with the logging program, CW and voice keyer integration, Rotator control

A PDF Presetation from the W0DXCC Forum on how to improve the performances of the popular Yaesu FT-2000 transceiver

Acom 1010 operating manual in english PDF File

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 two element beam antenna for ten meters band. This home-brew two-element beam is the perfect introduction to rolling your own gain antenna

This tutorial provides background information on the decibel and instructions for performing calculations involving decibels. This tutorial combines information from several authors, including Bob DeVarney, W1ICW; Walter Bahnzaf, WB1ANE; and Ward Silver, NOAX

This article will explain a few of the ways author use an external SDR and Linrad to enhance his K3 experience. Linrad is one of many available SDR receiver programs. The same could be done with any radio that lets you access its IF frequency output. Article from NCJ Nov Dec 2019

Article appeared on 73 amateur radio today in 1999 on how to unlock the secrets of sending precise Morse Code. Article contains hints on how use the stright key and the sideswiper key, but even the electronic keyers or the semiautomatic keys.

Can Home Solar Power and Ham Radio Coexist? It is possible, with minimal interference from the solar power system, provided you make some modifications.

A complete guide to start operating EME. In this document, that is the result of several years of experimenting, the author summarize the steps to begin on Earth-Moon-Earth communications

6 Elements on 50 MHz / 6 metres

A compact high G/T Yagi with bent Drive element by DG7YBN

Optimizing the Performance of Harmonic Attenuation Stubs

A folded dipole is an antenna, with two conductors connected on both sides, and folded to form a cylindrical closed shape, to which feed is given at the center.

A trap antenna dipole covering two differen bands made reusing an old 160/80m inverted vee antenna.

Six Steps for Programming your IC-2100H from the front panel of radio. Using these steps you should have no trouble entering either simplex or repeater frequencies and saving them.

A practical guide to program Chinese Radios like Baofeng UB and BF series hanheld trnsceivers

What is VSWR and why you should care, formal definition of VSWR and SeaSonde Measurements, formulas

Icom IC-703 HF + 50 MHz transceiver, english official instruction manual available in PDF File to download.

A practical guide on hombrewing Yagi antennas, including notes on Driven Element, Transformation & Symmetrising Coax Lines, Full Boom length vs. electrical length, Elements & Insulators on Boom and additional tips and tricks, in English and German

Operating in the **microwave** spectrum, Response Microwave, Inc. specializes in the design and manufacturing of RF and microwave signal processing components and subsystems. The company's product line encompasses a wide array of offerings, including Connectivity Series components, rotary joints, phase shifters, cable assemblies, surge protectors, terminations, Hybridline/Couperline products, circulators/isolators, directional couplers, quadrature hybrids, attenuators, custom assemblies, filters/diplexers, DC blocks & bias tees, power dividers/combiners, laser diodes & drivers, high-frequency connectors, and precision test accessories. This extensive catalog supports various applications requiring precise signal manipulation and transmission at elevated frequencies. The resource provides access to a comprehensive product catalog and a dedicated connector catalog, detailing specifications for components like **high-frequency connectors** and test cables. While specific performance data or comparative analyses are not directly presented on the main page, the breadth of products indicates a focus on providing foundational building blocks for microwave systems. The company emphasizes customer service and aims to be a reliable source for RF/Microwave/Optics product requirements, serving a growing customer base with its specialized component offerings.

From 1921 to 1924, radio amateurs experimented with transmitting across the Atlantic. Everyday Engineering magazine organized the first sending test with English amateurs prepared to listen for signals from the US

A Rig control CAT interface schematic suitable for both the Yaesu FT-817 and FT-100 transceivers.