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A large printable PDF file representing the world time zones. This map gives an overview of current local times around the world. If you ever asked yourself what time zone am i in, find your answer here.

An amateur radio contest log sheet printable in A4 format, useful for portable operations, free to download PDF File.

A rebuild job on a Heathkit SB-200 amplifier by N4NAB

Useful exercise sheet to learn morse code reception. In A4 format PDF File, it contains groups of 5 characters commonly used while learning morse code reception.

This antenna is intended for the 20-meter Band. There are two Voltage Fed Helical Dipoles, made with 2 slinky that fed with phase shift in 90 degree

Understanding Common Mode and Differential Mode Currents on Transmission Lines by K9YC

Building the double size G5RV antenna, part list, assembly part, dimensions and assembly instruction in a pdf document

This PDF document details the construction of a **70 MHz** Big Wheel antenna, a horizontally polarized omnidirectional array. The design utilizes three full-wave loops, each approximately **2160 mm** in diameter, arranged in a triangular configuration. The resource provides mechanical dimensions for the antenna elements and a comprehensive bill of materials, specifying component quantities and types, such as M8 stainless steel bolts, 15x15x1.5 mm square aluminum tubing for spacers, and 8 mm aluminum rod for the arcs. The central hub is constructed from two 160x160x8 mm aluminum plates, with four 40 mm long polyamide insulators supporting the radiating elements. The feed system incorporates a 50 mm diameter aluminum pipe for mounting and a matching stub constructed from a 120x20x2 mm aluminum sheet, connected via M8x10 mm bolts. The resource includes a diagram illustrating the mechanical dimensions and assembly points, including the N-connector fixing point and the center conductor attachment. The project was published on May 25, 2011, by Peter OE5MPL and Rudi OE5VRL. DXZone Focus: PDF | 70 MHz Big Wheel | Mechanical Dimensions | **2160 mm** loop diameter

Amateur radio good operating practices by KG9OM

VX-7/5R Computer Interfacing by Bas Helman G4TIC

Don't neglect one of the most important parts of your station!

A monster magnetic loop antenna for 160 meters band. This Magnetic loop is optimized for 1840 Khz + 50 Khz. PDF Article published on La Radiospecola 10.22

Enhanced SSB Audio (ESSB) is a specialized operating mode that extends the capabilities of traditional Single Sideband (SSB) voice transmissions. This presentation by K4QKY delves into the technical aspects of ESSB, discussing its advantages and the ongoing debates within the ham radio community regarding audio quality and bandwidth usage. ESSB aims to provide clearer and more natural-sounding audio, which can enhance the overall communication experience for operators. The presentation covers various topics, including microphone selection, audio processing techniques, and the importance of proper equalization. It also addresses the controversies surrounding ESSB, such as the potential for interference and the debate over whether it strays too far from traditional SSB practices. By understanding these elements, amateur radio operators can make informed decisions about their audio setups and contribute to discussions about the future of SSB operations.

The document titled 'Extending the Range of Your Handheld' by WG7S is a guide on how to extend the range of your handheld VHF UHF transceiver by using an external antenna. It provides information on comparing popular models, selecting the right antenna, and resources for amateur radio antennas.

Some basic antenna information for the newcomer

A PDF File of a Maria Maluca multiband HF antenna with schematic diagram, dimension and plan

Ground Plane - 1/4 wave vertical, J-Pole, 3 Element Yagi Beam and simple antenna supports

Learn how to start using ham radio satellites for your DX contacts, PDF presentation by Dave Long

Assembling a Code-Practice Oscillator, a PDF by ARRL

A 50-ohm generator feeding a 50-ohm line connected to a _quarter-wave transformer_ (150 ohms) terminated in a 450-ohm load is analyzed to understand transient behavior. The paper meticulously tracks voltage and current waves, reflection coefficients, and power levels through a sequence of events, starting from quiescent conditions. It details how incident and reflected waves combine and interact at impedance discontinuities, illustrating the dynamic changes in impedance and SWR at various points in the system. The analysis reveals that the impedance at the interface between the 50-ohm line and the 150-ohm transformer changes from 150 ohms to **64.3 ohms** after the first reflected wave arrives. Subsequent reflections cause the impedance to asymptotically approach 50 ohms, reaching **53.22 ohms** after five wave terms. The study also examines the generator's reaction to transient SWR changes, noting that a 3:1 SWR can temporarily reduce generator output to 0.75 watts, but these effects are temporary and diminish as the system approaches steady-state conditions.

Dragoslav Dobricic, YU1AW antennex article on influence of Boom on frequency performance and how compensate it

If you can program split-frequency memories in your dual-band radio, or your dual-band radio has two VFOs, you can work an FM satellite

In this PDF article Zack Lau describe how to homebrew a four element yagi beam antenna for 50 MHz band, including how to build mounting blocks and tubing clamps to hold elements.

Article by VU2GT about VHF antennas, how to evaluate performances and models.

A Compact and efficient multiband beam antenna based on a Modified W8JK Array by K5LJ

ZS6YI modifications for the Icom IC7000

FREE ham radio newsletter The K9YA Telegraph is in full-color and delivered to your computer each month as a PDF.

This project produces a sturdy tripod for small vertical antenna support using readily available electrical metal tubing (EMT) or conduit

An improved feed network for loop-type receiving antennas article published in NCJ October 2009 issue

The electrical characteristics of an antenna that are of interest to obtain by direct measurement are the frequency at which the antenna is tuned, the gain and radiation pattern

Article explain how create your own D-ATV station. By Ken W6HHC & Robbie KB6CJZ on RF Newsletter

A pdf file with drawings and instruction to properly assembly and solder most popular coax cable connectors

Collection of various Dubus articles in PDF format

QST Article on what you should know about matching networks for class C RF power amplifiers

A document about Repeaters what are they and how to use them in a pdf file format

An illustrated and printable introduction to PSK 31 by by Alan J. Gibbs, VK6PG

Many Hams suffer from a cruel obsessive-compulsive disorder. They're driven to achieve the lowest possible SWR even when it is not necessary by WB8IMY

A complete test report on Icom IC-7851 obtained with some lab tests, in a 21 pages pdf file.

Limiting static surges on dipoles, verticals or end fed antennas

Sometimes we need a little more output filtering than traditional designs offer. Look at a new filter that can give you that extra boost. QST article by W3NQN

Third-order Cauer filters can boost performance of multi-transmitter, multi-operator contest stations to the next level. The filters are practical and you don’t need expensive test equipment to align them.

Download the Yaesu VX-8R Cheat Sheet PDF File

Article by N6LF on a top band vertical antenna array system

Here is a simple, self-contained beacon which can run a few milliwatts or as much as a watt depending on choice of amplifier and supply voltage.

Donwload the Kenwood TL-922A user Manual

Get familiar with the basic operating procedures for using the JT65 mode of HF digital communications, a 35 pages PDF file.

QST Magazine Product Reviews - Key Measurements Summary - HF-Transceivers or Receiver and Linear Amplifiers

Project for DXers and experimenters alike. An old article publishes by 73 Amateur Radio magazine in PDF format, where all the components required to build your own HF spectrum analyzer may be found in a well-stocked junk box.

Fixing the IC-7000 noisy audio that can occur when IC-7000 audio output is connected to Hi-Fi earphones or external speaker.

Improving measurement accuracy when low-power analyzers are used.