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VHF channel usage, making a mayday call, and related informations

Comparing the ICOM IC-7600 and the Yaesu FTDX-3000

An information paper by the International Amateur Radio Union, History of 40m allocation, propagation properties of 7 Mhz band

There are many designs for building preamps each with their own advantages and disvantages. In this PDF Article author reviews several different types.

Presents the **BayCom** packet radio system, detailing both its hardware and software components specifically designed for amateur radio use. The resource offers insights into the technical specifications and operational aspects of the BayCom modem, which has been a staple for many German packet radio enthusiasts. It covers the integration of these components within a typical amateur radio station setup, enabling reliable digital communication. Further, the site provides a broader context by including general information about the German packet radio network. This encompasses network topology, operational protocols, and historical developments relevant to packet radio in the region. Users can find details on how to connect to and utilize the existing infrastructure, fostering participation in the local digital amateur radio community.

Complete guide to receive weather satelite images with a RTL SDR dongle and free software

German contest club

A 160W linear amplifier for 4 meters band based on GI0GDP

A presentation of the NBEMS and the importance of data transmission in Digital EmComm.

The W6NL Moxon Yagi is a high-efficiency two-element 40m Yagi that uses cross elements to provide both loading and Moxon coupling, addressing the challenge of deploying a directional antenna on the 40-meter band. This resource details the transformation of a _Cushcraft XM240_ Yagi into this Moxon configuration, replacing the original loading coil LCA sections with four new assemblies. The guide provides comprehensive instructions for building the boom and elements, including specific dimensions for new sections and tee loading elements, along with detailed drawings and a full parts list for the conversion. Performance data indicates the converted antenna achieves **10.73 dBi** gain at 7.050 MHz with 99.5% efficiency and a high front-to-back ratio. The VSWR bandwidth is over **300 kHz**, ensuring good performance across a significant portion of the 40m band. Construction involves reinforcing element sections, attaching tee loading elements with U-bolts, and implementing element guying using materials like _Phillystran_ to manage sag and maintain structural integrity.

1.2 to 30 Volts 1.5 Amps Power Supply

Kennedy Safaris, cheap,well organized and ham radio friendly

The Araucaria DX Group, based in Brazil, functions as an amateur radio club specializing in **DXpeditions**, **contesting**, and organizing various related events. The group actively sponsors contests and provides resources for DX enthusiasts. Its primary focus is on facilitating and participating in long-distance radio contacts and competitive operating events, contributing to the global amateur radio community. The group's activities include coordinating expeditions to rare DX entities, participating in major international contests, and fostering skill development among its members. By sponsoring events, the Araucaria DX Group supports the growth of amateur radio in South America, encouraging participation in competitive operating and promoting the pursuit of DX. The group's initiatives aim to enhance operational proficiency and expand the reach of amateur radio communications.

Popular italian amateur radio forum by ARI Fidenza include a section dedicated to swap and sell

Chart that present results of impedance measurements made on a variety of common-mode choke implementations across the frequency range 1MHz to 30MHz by G3TXQ

Have you ever thought of setting up a portable HF station for an activity ?

Marshall G. Emm, N1FN, meticulously examines iambic keying, dissecting its historical introduction in the late 1950s with transistorized electronic keyers and its purported advantages. The resource defines keying systems, electronic keyers, and various paddle types, including single-lever and dual-lever paddles, clarifying the distinction between iambic keyers and the iambic sending technique itself. It details the two main types of squeeze keying: true squeeze for alternating dot-dash strings and character insertion for specific elements within a character. N1FN critically evaluates the actual efficiency gains of iambic keying, referencing Chuck Adams, K7QO's, keystroke analysis. While a straight key to bug transition yields a 34.1% reduction and a bug to non-iambic keyer offers 16.1%, iambic keying provides only an 11% theoretical improvement. However, considering typical QSO text and Morse code's inherent optimization for common letters, the practical efficiency gain is estimated at a modest 4-6%. The article also highlights how iambic keying's reliance on precise timing gates can impose a speed limit, making it less effective above 40 WPM, where many operators revert to non-iambic methods or single-lever paddles.

A presentation of the Yagi Antennas, and other interesting tid-bits by Brian Mileshosky. The document provides an in-depth exploration of the Yagi-Uda antenna, detailing its historical development, design principles, and performance characteristics. Originally described in the 1920s, the Yagi antenna features a driven element and parasitic elements, including reflectors and directors, which collectively determine its behavior. The document highlights how element lengths, diameters, and spacing influence gain, impedance, and directivity. It also discusses the antenna's reciprocal nature and presents data on typical gain values for various element configurations. Additionally, the text covers practical considerations, such as the construction of a "Tape Measure Yagi" for amateur use, and touches on related antenna types like dipoles and their application in Near Vertical Incident Skywave (NVIS) communication.

Technical supplement manual of the Yaesu FT-8800R in english

The TransWorld Antennas TW4040 The Adventurer Monobander™ is a portable HF antenna designed for rapid deployment in field operations, including **SOTA** and **POTA** activations. This manual details the antenna's assembly, tuning procedures, and operational guidelines for optimal performance on the 40-meter band. It outlines the specific components, such as the telescoping whip and base unit, required for proper setup. Instructions cover mast erection, radial wire deployment, and impedance matching to achieve a low **VSWR** across the designated frequency segment. The document also provides guidance on antenna orientation and environmental considerations for portable use. It specifies the antenna's power handling capabilities and physical dimensions when fully deployed and collapsed for transport.

Non-profit public foundation dedicated to providing research and educational access to optical and radio astronomy. Located in Rosman, North Carolina.

Manual of the BD-35 Dual Band VHF UHF RF power amplifier by Mirage Amp

Modification leaves nearly all of the existing Omni agc circuitry intact, simply add an audio detector which modifies the delay characteristics of the original system by G3IXQ

Comparison of all the oscilloscopes available for hobbyists, digital oscilloscopes that you can get for under $500, or oscilloscopes that you can build yourself.

A dual band portable inverted V antenna for 80 and 40 meters band with dimensions for other bands and several assembling instruction

A homemade band pass filter for the 30 meter band based on the original VE7BPO design

Arizona near space research - promoting science and education by exploring frontiers in amateur radio and high altitude balloons.

Elecraft K3 vs. ICOM IC-781 vs. Kenwood TS-850: comparative Measurements and Experience

The _Letter Post Regulations_ article RL 128 defines specific dimensional requirements for address placement on envelopes, crucial for efficient postal processing. The addressee's address area must be positioned at least **15 mm** from the right and bottom edges, and at least **40 mm** (with a 2 mm tolerance) from the top edge, extending no more than 140 mm from the right-hand edge. These precise measurements ensure rapid optical reading and facilitate manual sorting and delivery by postal services. Adherence to these Universal Postal Union (UPU) standards prevents interference with indexing, coding, and address detection areas, which must remain blank. While individual countries may adapt these values, they must maintain a minimum address area width of 74 mm. Proper placement avoids extraneous markings to the right, below, or within a 15 mm wide area to the left of the address, extending from the first line to the bottom edge, and a 15 mm high by 140 mm long area from the bottom-right corner.

Keyclicks and NB modifications for the Yaesu FT-1000MP Mark-V HF transceiver

Antennas are influenced by the effect of the ground and by the type of conductors from which they are constructed. Effects of various types of grounds on a 1.825 MHz horizontal 0.5 wave dipole

The Central Arizona DX Association is an ARRL-affiliated club.

A custom manual for the Yaesu FT 450 owners, tha includes system controls, factory reset procedure, procedural uses, memory management, programming and many more

Activities, legal infos, technical articles, photos, vendors, software, and links

Homebrewing portable antennas for field day operations

How manage and quantify ground loss in vertically-polarized antennas by VE3VN

AudioXplorer is a sound analyzer software designed for Mac OSX, provide a real-time analysis window where you can visualize the sound spectrum and sonogram

A Personal Museum of Military Radios - Spy Radios - Tubes by Antonio Fucci

Calculate how to set call signs

Icom IC-51A out of the Box Programming Instructions PDF file by dstarinfo.com

Home page della Sezione ARI di Gorizia

The Associazione Radioamatori Italiani (ARI) Bergamo section provides a local hub for amateur radio operators in the Lombardy region of Italy. This resource details upcoming events such as the annual _Panettonata di Natale_ and important administrative updates like the 2026 membership renewal process. It also highlights special operating activities, including a commemorative radio activation for the 101st anniversary of the Gleno Dam disaster, which involved operators from both the Bergamo and Vallecamonica ARI sections. The site serves as a central point for local hams to stay informed about club activities and operational opportunities. Members can find information regarding payment methods for annual dues and event schedules. The Gleno Dam activation, for instance, is a significant event, demonstrating the club's engagement in historical remembrance through amateur radio. Such activities foster community spirit and provide opportunities for members to participate in public service and special event operations, often generating **hundreds of QSOs** and promoting the hobby.

Ari Lecce official web site

The Hexbeam is a great little antenna! It should be high on your list of options if you want a design that can be multi-banded, exhibits useful gain and directivity, is very lightweight, has a small turning radius, and which lends itself readily to Do It Yourself construction.

Two different ways to create autotransformer for end fed half wave wire antennas, by using ferrite or air core.

A homemade 23 cm transverter project with several building steps and pictures

ARI Macerata Official Web Site

Maritime Mobile Service Net for disaster help on high seas on foreign lands

Amateur Radio on the International Space Station european web site

DXpedition by Rene/DL2JRM, Bodo/DL3OCH, Dan/DL5SE, Daniel/DL5YWM & Anett/DO6XX