Search results

a portable 2 elements tri band yagi

G8ODE 160 m Top Band Inverted L Antenna made of 33m horizontal wire in the garden

The ITU and CQ Zones Map is a printable two-page PDF provided by Icom, displaying the world divided into ITU and CQ Zones. The purpose is to assist radio amateurs in identifying and understanding these zones for communication purposes.

Simple gain antennas for the beginner, a 2 element HF yagi antenna

The K4VX linear-loaded dipole for 7 MHz, simple and practical way to make a short but efficient 40-meter dipole.

Includes the PDF file of the General Class study guide by Dan Romanchik KB6NU free to download.

A Parasitic Lindenblad Antenna for 70cm by Anthony Monteiro, AA2TX. This is the official 16 pages PDF File published by AMSAT about the 70cm Parasitic Lindenblad Antenna.

Make your own rf step attenuator

Do your multiple-transmitter field day or contest efforts suffer from intrastation interference ?

Demonstrates the construction of a **homebrew spectrum analyzer** designed by Wes Hayward, W7ZOI, and Terry White, K7TAU, enabling radio amateurs to build a capable test instrument without significant expense. The resource details a _double-conversion superheterodyne_ circuit, employing intermediate frequencies of 110 MHz and 10 MHz, and covers essential blocks such as the time base, logarithmic amplifier, resolution filters, and local oscillators. It highlights the use of hybrid and monolithic ICs, including mixers, amplifiers, and VCOs, to simplify construction while maintaining performance. The design supports useful measurements in the 50 kHz to 70 MHz range, with methods outlined for extending capabilities into VHF and UHF. The authors emphasize that this analyzer, while simple to build, is intended for serious measurements, requiring careful control of signal levels to avoid spurious responses. It uses an oscilloscope for display, with specific instructions for calibration and adjustment of various stages, including the log amplifier and IF gain. The guide provides detailed schematics and component lists for each section, such as the 110 MHz triple-tuned band-pass filter, which achieved **90 dB** image rejection, a significant improvement over double-tuned circuits. Practical advice on alignment and troubleshooting is included, drawing on the authors' extensive experience in RF circuit design.

An air cored 1:1 balun for 3.5 to 30.0 MHz

Operating within the amateur radio HF spectrum requires adherence to established band plans and considerate practices. This guide from the ARRL outlines commonly accepted frequency ranges for specific modes and activities, spanning from 1.800 MHz to 29.680 MHz. It delineates segments for **CW**, **SSB**, RTTY/Data, SSTV, Digital Voice, and AM operations, including dedicated QRP calling frequencies and DX windows. The document emphasizes that these are not regulatory mandates but rather widely recognized conventions, acknowledging that high-activity periods like DXpeditions or contests may lead to temporary deviations. It explicitly references Section 97.101(b) of the FCC Rules, asserting that no station holds exclusive rights to any frequency. The guide also lists frequencies for IBP/NCDXF beacons and automatically controlled data stations. Practical advice is provided regarding frequency selection, stressing the importance of checking for existing use before transmitting. It also mentions ARRL band plans for frequencies above 28.300 MHz, directing operators to additional resources.

A homemade Magnetic Loop antenna from a spare 3m length of RG213 working from 30m to 15m with a 130pF tuning capacitor

This free PDF file contains two Worldwide grid square maps. The first map displays the fields (first two letters of a maidenhead locator) while the second includes also squares (third and fourth digit) and it can be useful to determine what is your ham radio grid square. PDF file can be enlarged and scaled to A3 and higher dimensions.

This PDF document, authored by KT4QW in October 2004, details the construction and modeling of a dual-band, horizontally polarized hanging rectangular loop antenna for **10 and 17 meters**. The design, adapted from *The ARRL Handbook*, utilizes _NEC4WIN95_ software for scaling and optimization, targeting a 50 ohm feedpoint impedance. The resource includes a bill of materials, step-by-step construction instructions, and a discussion of the antenna's radiation characteristics. It presents NEC-generated elevation and azimuth patterns, comparing the loop's performance to a half-wave horizontal dipole at the same height and frequency. The 17-meter element is centered at 18.140 MHz for low SWR across the phone band, while the 10-meter element is centered at 28.500 MHz. Construction involves 14-gauge stranded copper wire and Schedule 40 PVC spreaders, with the total wire length calculated by the formula: Length in feet = 1005/MHz. The feedpoint impedance can be adjusted by modifying the rectangular aspect ratio. The document specifies hoisting the antenna to at least a half-wave above ground for testing. It notes that a balun was tested and found to have no measurable effect on SWR or radiation characteristics. A 2-meter scale model is presented to illustrate the physical design, and a "rotator" string is incorporated for directional adjustment up to 90 degrees.

G8OFZ multi-band antenna for 80-10m, this antenna appears to be a derivative of the Doublet and the Classic G5RV

1993 QST Article of a 2 meter beam antenna by WB0CMT

Article shows how to develop a good external ground system to complete your station's protection.

Technical questions answered about grounding techniques, in pdf file

5 Band 1/4 wave Telescopic Antenna. The 20m to 10m, antenna is simple and cheap to make, and has a performance that matches commercial antennas but at cost considerably lower. The design was purposely based on a telescoping fibre glass fishing rod as this allows it to be easily stowed away in the car.

G8ODE antenna project, where the 40m & Short 80m antenna was deployed as a sloping wire antenna using the 10M fibre glass fishing pole and a hook on the house's gutter-board

If you can't get on the air from home, the Internet may provide the answer. By Brad Wyatt, K6WR. Pdf File.

A free to download and print, paper log sheet for shortwave listerners in PDF format.

Bill Orr W6SAI ham radio techniques. Improving ground connection, computer analysis of the antenna, modelling sample antennas pdf file

If you are looking for an easy antenna for your favorite band, you can't go wrong with an halfwavelenght dipole, all you need is 3 insulators and some wire

Doublet multiband antenna for 80 to 10 meters band by

Compiled by Dan Stegner KC0OBU from FISTS CW Club member tips, amateur radio morse code procedures

The Arrow Antenna is a design classic: it combines light weight, compact design and functionality in a single package for operating FM dual band satellites such as AO-27, UO-14, SO-41 and SO-50

Contest LogChecker is a set of contest tools for Microsoft Windows, combining advanced text editing with keyword highlighted, and the ease and flexibility of import, export, statistics and charting utilities. With LogChecker you can edit, fill in the log, check Cabrillo Format and Header, convert files from the most popular logging software to Cabrillo, print customizable files, calculate statistics and export logs to RTF, PDF or HTML for publishing. You can examine a log in many different ways by highly interactive methods. LogChecker includes a Master Callsign Database tool for managing databases, which have been generated from actual contest logs. Commercial

N1TEV high performace regenerative receiver design

Theory, Modeling, and Practical Applications By W5JCK, presentation in PDF File. This presentation focuses on Near-Vertical Incidence Skywave (NVIS) antennas, which are crucial for short-range radio communications, particularly in military and emergency contexts. It explores NVIS theory, antenna models, and installation criteria while debunking common myths about reflectors. Key topics include usable frequency bands, optimal installation heights, and the impact of soil quality on performance. The presentation outlines the best bands for daytime and nighttime use, emphasizing the importance of understanding propagation characteristics to enhance communication effectiveness within 200 to 300 miles.

The free pdf book is a compilation of articles congenial to QRP published on 2003- 2005 years at free e- magazine AntenTop. 17 Mb pdf file.

ARRL pdf file on how remove car noise from your radio. Modern vehicles are RF noisy environments. Come learn how to identify and silence yor mobile noise sources, by WA6PDP

Adalet wireless document on antenna basics in a four pages pdf file

In this designs G8ODE explains different methods to builds a choke balun

Free Donwload of the PDF file of ITU and CQ zones of the world, made available by Icom America

Here is how to adjust this popular tuner circuit so it transfers maximum power to your antenna without going snap

A multiband antenna that can work from 80 to 10 meters in this illustrated docuemnt by G8ODE

By ON4CFC Pascal, describe how to build a Sperrtopf or Sleeve antenna for the 144 Mhz, PDF File by antennex

A 40 80 dipole antenna design by WA6ESC PDF File

Here is a very simple and practical way to make a short but efficient 40-meter dipole. The K4VX Linear-Loaded Dipole for 7 MHz

List of mods for the ICOM IC-7000 with many PDF Files

A monoband yagi for 14 MHz a PDF article from 73 amateur radio magazine by AB4GX

Band-pass filters can be critical components in competitive stations. This setup may help put your station on the map.

The AMRAD Active LF Antenna. You can tune into LF activity with this easy-tobuild and erect active antenna. As a bonus, you get MF and HF coverage, to not to mention world-class performance

This attenuator is worth your attention. Built like the proverbial brick outhouse, it's one you can easily duplicate by N9SFX Pdf file

A Comprehensive roundup of the most popular QRP transceiver kits on the market in recent years in PDF format

A different approach can help you optimize attic-bound aerial by W6HPH

High speed silicn diodes work well as RF switches. This article describes how to use diodes for selecting two or more filters ARRL QST article by W1FB

TL922 Service manual