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Complete guide to build Jpole antennas with online dimensions calculator.

U.S. Government's military handbook on grounding in pdf format

F6EZX presents a detailed account of constructing a compact, multi-band _Levy antenna_ for portable holiday operations, specifically addressing issues with local QRM from a previous _Deltaloop_ setup. The article outlines the design criteria, including multi-band operation on 40m, 30m, 17m, 15m, 12m, and 10m, a symmetrical configuration to reduce interference, and a low take-off angle for DX. Construction involves 2x 10.3m radiating elements and a 15.3m open-wire feeder (ladder line) with 7cm spacing, made from 1.5mm2 copper wire and foam pipe insulation spacers. Theoretical calculations, referencing F9HJ's "_Les antennes Levy_" book, guide the determination of element lengths and feeder impedance characteristics, aiming for a good match across bands with a commercial antenna tuner. Initial field tests with the _VCI Vectronics VC300DLP_ tuner showed a 1:1 SWR from 80m to 10m, with some difficulty on 17m. The antenna, mounted as a 45-degree slopper with the high point at 12m, successfully facilitated DX contacts to South America, particularly Chile and Argentina, suggesting a lower take-off angle compared to the previous Deltaloop which favored Brazil. The Levy antenna significantly reduced TVI/RFI, attributed to its improved symmetry and greater distance from the QRA. While signal reports on 15m and 20m were 1-2 S-points lower than the Deltaloop, its performance on 40m and 30m was comparable, fulfilling the design goals for a portable, low-cost, multi-band solution.

U.S. Marine Corps in PDF format

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.

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.

LOGvrr, a **freeware logging software** developed by IN3VRR, provides amateur radio operators with essential tools for managing their contacts. The resource details various downloadable components, including the core LOGvrr application, an international callbook with approximately 1.8 million callsigns, and utility programs for installation and data conversion. It supports functionalities like logging QSOs, managing awards, and interfacing with PacketCluster systems, with specific instructions for installation on Windows operating systems, including compatibility notes for Windows 10 and 11 using Hyper-V or DOSBOX. The site also offers external tools and documentation, such as the FAQ_VRR.PDF manual which covers installation, printer configuration, ADIF conversion, and Packet setup. It references third-party software like Mercurio and BV QSL Management for QSL printing, and ADIF2QSL for label printing, highlighting LOGvrr's ability to export QSOs in **ADIF format** for integration with services like LoTW. The resource includes historical updates, with the latest core component update in August 2014, and notes on the CallBook's maintenance up to 2015.

Helical antennas have long been popular in applications from VHF to microwaves requiring circular polarization, since they have the unique property of naturally providing circularly polarized radiation. Paul Wade W1GHZ

Some printable logbooks or logsheets, made to use whilst operating portable. Download free PDF files in landscape and portrait A4 Format.

The Resonant Feedline Dipole (RFD) HF antenna design utilizes a single piece of coaxial cable and a stranded wire section, forming a 1/4-wavelength radiator. This configuration, based on a 1997 ARRL Handbook design (page 20.17), functions by RF traveling on the inside of the coax shield and returning on the outside, creating the second half of the dipole. A choke wound into the feedline prevents RF current from flowing back down the feedline. Construction details include using RG-58a/u coax for a 75m version, with a 1/4-wavelength section of stranded wire soldered to the center conductor. The document provides choke dimensions for RG-213, RG-8, and RG-58 coax across 3.5 MHz to 28 MHz, specifying cable length and number of turns. Dipole dimensions are also tabulated for frequencies from 3.6 MHz to 28.4 MHz, listing overall length and individual leg lengths. Field tests included deployment near Bryson City at 5 feet off the ground and as a sloper during WCARS Field Day in Asheville, yielding successful local and regional contacts.

A scanned PDF of this interesting book on HF Dipole antennas published by Stanford Research Institute

Ebook by Akira Matsuzawa Tokyo Institute of Technology, Building blocks in RF system and basic performances, Device characteristics in RF application , Low noise amplifier design, Mixer design and Oscillator design

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

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

Facilitates logging of amateur radio contacts directly within a web browser, enabling seamless operation across various devices including Windows, macOS, Linux, iOS, and Android. This web-based application stores all log data securely in the cloud, providing accessibility from any internet-connected location. It supports importing existing log data via CSV files, with future plans for _ADIF_ file import, and offers a robust QSL card generation feature, producing print-ready PDF files in standard 148mm x 100mm dimensions. The platform integrates with Japanese government databases to automatically populate callsign-related information such as station location and license issue dates, streamlining data entry. It also assists with JCC/JCG searches for accurate QTH logging. The service leverages SSL encryption for all communications and benefits from security oversight by certified information security professionals. Users can register using email/password or existing Facebook/Google accounts, and the beta version is currently available for free. The system has processed over **5,297,881** logs, with **28,369** logs recorded in the past 24 hours.

Free pdf book on Nicola Tesla. He is the true unsung prophet of the electric age; without whom our radio, auto ignition, telephone, alternating current power generation and transmission, radio and television would all have been impossible

The W0IS resource outlines methods for finding historical US amateur radio call signs, particularly for genealogical research. It highlights the comprehensive collection of digitized call books from 1906-1996 available at leehite.org, stored as searchable PDF files. These resources significantly simplify what was previously a laborious manual search through physical call books, which were typically indexed by call sign rather than name. The guide details specific search techniques for various eras. For early radio days (1913-1923), government call books are readily available and searchable online via Google Books and hathitrust.org. For the period between the 1930s and 1980s, when private publishers like "Radio Amateur Call Book Magazine" dominated, the resource points to archive.org for scanned editions (1938, 1940, 1948, 1972) that support full-text OCR searches, despite potential scanning errors requiring flexible search terms. It also provides strategies for navigating Google Books' "snippet view" for the 1952 call book, including searching by name or address and interpreting often illegible snippets. The resource suggests cross-referencing findings with hamcall.net for call sign verification from 1921, 1954, 1960, 1969, and 1983 onwards. Additionally, it lists physical call book collections at institutions like the Pavek Museum of Broadcasting and individuals like W3HF, offering avenues for deeper research when digital methods fall short.

Free to download PDF book about operating The VHF/UHF bands written in the early to mid-1990s by a team of experienced VHF/UHF DXers and equipment developers, in an effort to pass on their knowledge and stimulate further developments.

The AN-55A ATV Handbook PDF is a document providing information and guidance on Amateur Television (ATV) for hams interested in setting up and operating ATV systems. The handbook covers topics such as equipment, setup, operating procedures, and technical details related to ATV transmissions. It is a useful resource for hams looking to explore the world of ATV and engage in video communications through amateur radio. The content aims to educate and inform hams about the intricacies of ATV technology and operation.

Free PDF book to start learning morse code and to improve your proficiency, freely available in four languages english, german french and italian.