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A Center-Fed Half-Wave Dipole is probably the simplest of antennas to construct and use. It is usually suspended between two supports, from it's end insulators, and has the feedline hanging from the center.

Equipment and procedures to monitor ACARS

End-Fed Half-Wave Antennas (EFHWAs) are analyzed for their utility in portable QRP operations, emphasizing their simplicity, efficiency, and predictable radiation patterns compared to other portable antenna types. The discussion contrasts EFHWAs with vertical antennas, random length wires, and center-fed dipoles, highlighting the common pitfalls of each, such as ground system dependency for verticals and feedline issues for dipoles. The article details the electrical half-wavelength calculation using the formula L (Ft) = 468/F(MHz) and explains how EFHWAs can be resonant on harmonic frequencies, enabling multiband operation. Various deployment configurations are presented, including the inverted L, inverted Vee, sloping wire, and vertical setups, each with specific advantages for radiation angle and polarization. For instance, a vertical EFHWA offers a low angle of radiation suitable for DX contacts without requiring an extensive ground system. The resource also addresses the counterpoise requirements, suggesting a quarter-wavelength wire or connection to a metallic structure for decoupling. A schematic diagram for a simple parallel-tuned circuit tuner, based on the _Rainbow Bridge/Tuner_ design, is provided, detailing component values for 30 and 40 meters, including a 6 microhenry toroidal inductor and a 20-100 picofarad mica compression capacitor. The tuner's adjustment process for SWR matching is also outlined.

Eighteen-part tutorial on packet radio in HTML and ASCII format from Larry Kenney, WB9LOZ

Experience of band filters, for a contest multi operator enviroenment

The function of the calculator is to give all of the needed sizing to construct a good 5 element quad antenna for amateur radio use.

Active digital mode frequency list compiled by Jason Buchanan - N1SU

This is a base-loaded vertical antenna that mounts on the car's roof. The loading coil is designed as a variable inductor, with a three-legged chariot that travels up and down inside the coil, with grooved brass wheels running on the coil turns, and driven by a slotted rotor tube.

It is very easy to create a simple 1/2 wave dipole, all you need is some lengths of wire such as the core of some mains flex or even a straightened out metal coat hanger, some co-ax cable and a connector for your scanners antenna input

Butterfly capacitors are hard to find, expensive but they can be home made by PY1AHD

An introduction to DIY building of a concrete base for a 45' mast.

Get the most out of the shortwave listening hobby. Follow these steps to get started with your new radio.

A sensitive RF probe is very useful in a situation where an oscilloscope is not available

Cancelling out unwanted noise sources by DL3FP

Build a Low Power 4:1 Balun , by Charles Greene, W1CG with full-color, full-resolution graphics from the pages of QRP Homebrewer

Simple, inexpensive and easy to erect, this antenna provides directivity, low angle radiation and a small gain on a number of HF bands.

A VHF Quad antenna for teh two meters band in italian

A standard 6 elements design scaled for UHF application. All material used in this project are easily obtainable tubes and rods which is limited within a total budget of $18.

Reccomendations and tips for VHF-UHF operation

This DIPLEXER separates 2m from 70cm on the same coax cable, and allows to use 2 antennas over the same cable and permits transmission on one band and simultaneous receiption on the other band by hb9abx

N5IW ideas to build your own antenna in a restricted lot, or a stealth antenna. Includes PPT files of HF and VHF stealth antennas.

CallBook is an Amateur Radio application that allows you to look up call signs via the free WM7D server, the QRZ Online subscription service or the HamCall subscription server and track active APRS stations on www.aprs.fi. Lookup results can be emailed and the QTH can be instantly viewed in the Maps application

An easy to build moxon antenna for portable use. A Moxon Rectangle is a two element beam, where both elements are folded towards eachother.

A multiband end-fed antenna that cover 3.5 to 30 Mhz using a 1:64 Balun based on a FT240-43 core

The ultimate satellite Omni Antenna by Howard Sodja, W6SHP. The Lindenblad antenna consists of four half wave folded dipoles slanted 30 degrees to the horizon, oriented 90 degrees to each other in azimuth, spaced 0.3 wavelength apart

Several projects which will allow you to build your own RF design test equipment.

One of the best antenna values on the market is the LightningBolt Quad. At about half the cost of a tri-band yagi, you get five band coverage with a single coax feedline and excellent performance from a light, low wind load antenna.

Features and specifications for discontinued yaesu ft-100d radio

Conversion notes and amateur radio firmware especially for Finnish PMR radios and cellular phones like Nokia, Mobira and Benefon. Also some information for other European brands (Ericsson, Key Radio/Kyodo, Philips) and an extensive link collection.

The Dual-Band Wire Beam was inspired by L.B. Cebik's (W4RNL) article The Elusive Moxon Nest. Fiberglass tubing spreaders, Flexweave elements, an aluminum hub, and two die-cast aluminum flanges combine to provide a 12/17m Moxon nest with one 50 ohm feed.

Online javascript antenna calculator designed to give the critical information of a particular beam antenna, in this case a seven element Yagi, for the frequency chosen.

The Yaesu FNB-78 Battery plugs into the FT-897/D. It produces 13.2 VDC at 4500 mAh. The radio can hold one or two and one can be in use while the other is charging.

A simple to build Yagi 2 element antenna for 15 or 20 meters band by 9m2mso

How to solder PL-259’s compiled by K1VR

The webpage provides information on a two-element Yagi antenna for 24 Mhz, created by IK4DCS. It includes details on the design and construction of the antenna.

A slightly different 6M antenna project by N1GY, an Off center fed antenna for the 50 MHz.

SerialKey is a Freeware DOS Morse code keyboard that uses the serial port, by Jeff Rowberg (KF6RLU)

AM loop antenna for 75/80 meters band

STSORBIT PLUS, usually known as STSPLUS, will track the space shuttle or any satellite for which orbital data (TLEs) are available. A brief description of the program and several screen capture examples follow the links for downloading the program files.

This resource presents over 100 Q-signals, each with its corresponding question and answer format, as standardized by the International Telecommunication Union. The content delineates how these abbreviations can be expanded with additional groups, call signs, place names, or numerical data to provide specific context. It clarifies that a question mark following an abbreviation or its complementary information transforms it into a query. The document highlights that these operating signals, or Op Sigs, are prescribed for international use across all communication types, including military and non-military applications. It references their inclusion in Appendix 9 to the Radio Regulations Annex of the International Telecommunications Convention (Atlantic City) 1947 for QRA to QUZ blocks, and ICAO publications Dec 6100-COM/504/1 for QAA to QNZ blocks. The page specifically marks Q-signals of particular interest to amateur radio operators in red. The utility of Q-signals for concise communication in radiotelegraphy is evident, providing a structured method for conveying complex information efficiently. The resource serves as a practical reference for operators needing to quickly interpret or formulate messages using standardized codes, particularly beneficial for CW operation and international contacts.

An interface for amplifier to TS-850S

The 40/60/80 is a portable loop that covers 80 meters with a high degree of compromise

The **Black Cat CW Keyer** is a macOS application designed for amateur radio operators to transmit Morse code directly from their computer. It provides functionality for typing text to be sent, either immediately or buffered, and allows for the creation and transmission of pre-defined messages via single-key shortcuts. This software addresses the need for a flexible and accessible CW keying solution, particularly for Mac users who might find fewer dedicated ham radio applications compared to other operating systems. It integrates basic text-to-CW conversion, offering a straightforward interface for generating Morse code signals. Operators can utilize the Black Cat CW Keyer for various CW activities, including casual QSOs, contesting, or beacon operation. Its ability to buffer text allows for smoother transmission, while the single-key macro feature streamlines repetitive message sending, such as CQ calls or contest exchanges. While specific comparisons to other CW keying software are not detailed, its macOS focus provides a niche solution for Apple users. The program's utility lies in its direct approach to computer-based CW transmission, making it a practical tool for those seeking a dedicated **CW keyer** on the Macintosh platform.

An home made 70 cm colinear antenna at M1KTA blog

Quagi 8el 70cm improved 13.77dBi by IK1HGE

Match & display imped of antennas, can graphically visualize and compare two sets of measured impedances simultaneously.

Smith is a professional Computer Smith-Chart Tool and S-Parameter Plot for windows, special price for hams and students by Fritz Dellsperger

An homebrew project for a 3 elements yagi monoband antenna for the 20 meters by 9M2MSO

The Windom antenna was widely used in the 1930s and is named after the amateur that wrote a comprehensive article about it

PA11019 Travel loop antennas, these antennas cover 6.300 to 29.200 mHz , handle 35 Watts and have a packing size of 43 cm, ideal for fieldwork, or mobile operations.