Make and automatic antenna tuner based on Arduino and using economic card. This ATU Project can be installed outdoors and controlled remotely by an rs485 link

Choking balun for lower HF and MF bands. (1.8MHz – 10MHz). Requiring a choking balun to isolate the potential RF pick up on the coax cable as it runs past equipment such as computer within the radio room at lower HF and MF frequencies a simple method of winding RG58 coax onto a Powdered Iron Toroid Core was constructed.

A complete guide for newcomers edited by the Radio Amateur Society of Australia Inc. This free PDF includes several basic articles for new hams, with particular reference to Australian regulations, but is however a good guide for those who are aproaching the hobby worldwide.

What is antenna polarization, and why does it matter. Horizontal versus Vertical versus Circular polarization. Undestanding how antennas perform better with different polarizations.

UK based manufacturer of digital mode PC fully isolated interfaces. Includes several types of interfaces including USB interfaces for CW and Digital modes

How to improve your transmitting antennas for very low solar activity periods, vertically polarized 160 meter antennas, horizontally polarized 80 to 10 meter antennas, single or stacked yagis, multi-tower stations

Ferrite-shop is an on-line shop for ferrite toroids, cable cores and cable clamps based in The Netherlands

The interactive Smith chart enables users to navigate their way around a Smith chart, using simple discrete element impedance matching. This page allows users to try using the Smith chart, for education and interest purposes, without installing any software. Try changing the value in the load box to see the location of the impedance on the chart.

Cable for connecting APRSdroid to a Baofeng UV-82 Radio (APRS via RF)

An home made VNA made with Arduino Nano. This project features an LCD display 4×20 works from 1 MHz to 60MHz, can use bluetooth connection with Blue VNA android app.

A multi-band portable vertical antenna can be built with relatively ordinary components obtained from the local hardware store, including replaceable loading coils

Select the toroid by material type and dimension of the toroid, the desired inductance and you will get the numbers of turns

An online morse code trainer application that allows to select the digits and play them at the wpm speed you desire. While decoding will evaluate the results and will indicate your proficiency level

Military time notation is based on 24-hour clock. A time of day is written in the form hhmm, where hh (0-23) stands for full hours that have passed since midnight, mm (00-59) is the number of minutes that have passed since the last full hour. To convert hours greater then 12 to 12-hour clock just subtract 12 from the given hours and that will give you the PM time

KM Rover is a rover logger software for BIG 4 VHF UHF contests and generic, Spring and Fall Sprints, GPS interface, beam heading CW PTT DVK functions. Works on Windows

This utility will convert any amateur radio logbook that has been stored in Microsoft Access MDB format and convert the file into either a delimited CSV file or to an ADIF formatted file

Notes on how to properly install a Mini Whip receiving antenna in an noisy urban environment.

T2FD is a 600-900 ohms folded dipole, terminated with resistor. Feed impedance is coupled with 50/600 ohms voltage balun. It is a wide band antenna with rather low SWR over the full designed frequency range: antenna tuner is seldom needed.

Can Home Solar Power and Ham Radio Coexist? It is possible, with minimal interference from the solar power system, provided you make some modifications.

A folded dipole is an antenna, with two conductors connected on both sides, and folded to form a cylindrical closed shape, to which feed is given at the center.

This utility program shows the impedance and reflection coefficient parameters (SWR, reflection coefficient magnitude Rho, or Return Loss RL in dB) at both ends of a transmission line and the details of power loss in the line. It includes built-in specifications for approximately 100 different line types. You can modify the specs to see how small changes affect the results or to specify custom lines. All program inputs may be changed directly or you can use spin buttons to make the changes.

This is a WebSDR receiver, located in Friedrichshafen, Germany (at Lake Constance) using a multiband dipol and a FUNCube Dongle Pro+.

WebSDR receiver located near Krizevci, Croatia with 0-2 MHz, 60-80 meters band and 40-49 meters band

The Micro24 is a ultra compact microsize QRP SSB transceiver for the 20 meters amateur radio band. This transceiver is so small that it fits into one hand.

Homemade moxon antenna for the 40 meter band. This article is not very descriptive but includes some very detailed images

The receiving antenna setup for the top band, made with a 9 elements vertical antenna array, remote controller and remote relais.

How to make a dual-band VHF/UHF handheld Moxon Antenna to work satellites

In this article the author shows the receiving loop antenna for 160 meters band installed at his QTH. Diagram and movie available. Article in in Turkish but can be translated in english

A homemade simple and inexpensive portable antenna support, handy for quick trips to the field and other portable operations

The NanoVNA is a very compact handheld Vector Network Analyzer. The NanoVNA is tiny and portable analyzer, and it offers a high performance capabilities with an embedded lcd display.

This article describes the construction of a high performance transmitter and receiver for SSB (voice) communication covering the 14MHz (20 meters) high frequency amateur radio band with output range 15 to 20 watts and a top audio sound quality both on transmit and receive.

This software connects to a NanoVNA and extracts the data for display on a computer, and for saving to Touchstone files.

DK7IH QRP transceiver for 14 MHz. This small and compact home made transceiver with a max power output of 5W, the VFO module is based on the clock oscillator chip Si5351A by Silicon Labs ATmega168 and OLED 1306

A home made RDF 3 elements Yagi that can be used for fox hunting. The particularity of this antenna is that it can be folded, in order to save space while travelling. In Dutch.

Horizontal polarized omni directional 50MHz Antenna. This antenna is intented to use in a contest station as a second system beside the stacked yagi beam system. An omnidirectional systeem can be an advantage when it comes to short openings on wich the operator must react quickly.

A half-wave antenna can be end-fed or center-fed. An end-fed half-wave antenna may offer mechanical and construction advantages over a center-fed antenna. The radiation pattern for an end-fed half-wave antenna is no different than a center-fed half-wave antenna.

Digirig is an open-source integrated digital modes interface for amateur radio. As a differentiating feature, Digirig only requires a single USB connection to the computer with all the digital goodness packed in a single small enclosure. The internals include a USB hub, audio codec, a fully featured serial CAT (Computer Aided Transceiver) interface, and potentially other modules such as GPS receiver for time synchronization.

A home made battery charger 110-220 v AC providing from 1.25-24 v DC Adjustable at 8 Amps output power, with Short Circuit Protection Over Load and over charge Protection.

Open Two Radio Switching Protocol Antenna Selector on ATMEL ATmega8 microcontroller

TNXQSO.com is created for the information support of DXpeditions and special stations. You don’t need to create account unless you want to use this website for your DXpedition/station.

On-line log for Z21RU DXpedition to Zimbabwe

Summit Prowler 6 is a pocket-sized SSB/CW transceiver for 80, 40, 30 and 20m

20W portable handheld SSB transceiver for 20 meters band

Ultimate HAM Radio LogBook for Windows for both beginners and experienced Dxers. It features several functions like complete logbook with powerfull search capabilities, FT8 and LoTW integrations, DX cluster. Cat Interface to control your radio, licence is based on yearly subscription.

DxCalendar news from DX international scene. DX Bullettin with DX Stations calendar

A pocket-sized homebrew 40m CW QRPp/QRP transceiver

A windows program to learn Morse code and doing QSO in CW. The training course contains 39 Lessons based on Koch method. It can sends only letters, only numbers, only punctuation

This page describes a printed circuit board that you may use to build a QRP keyer.

Building a Windom HF Antenna. A PDF file presentation about homebrewing a windom antenna for the HF bands with formulas for 40 and 80 meters bands and step by step guide on making a 4:1 balun to feed the antenna.

A collection of ham radio clip art royalty free. Additional amateur radio clip art can be found changing the search terms.

Online HF Communication prediction system provided by the Australian Governament Buerau of Metereology allow to predict usable frequency rage for radiocommunications between two stations allowing to specify frequency and date range. This tool allow calculation with different methods and algorithms

The yearly, black, up to 1750, and monthly red, from 1750 up to now, sunspot numbers provided by the Royal Observatory of Belgium SILSO

This page displays the current ionogram and tries to determine the nearest digisonde report to your location. Data coming from this sondes are used to determine the MUF for oblique propagation on HF spectrum

This paper presents the method of calculating the maximum usable frequency (MUF) and field strength of radio waves reflecting 2 times at the F2 ionosphere layer under inhomogeneous conditions of the ionosphere. The comparison between predicted and measured MUF has shown that the proposed method significantly increases the accuracy of calculation MUF.

This article provides details on building a 6 Meter J-Pole antenna using PVC pipe for an enclosure.

A family of small size QRP SSB transceivers for the 15 MHz. Includes a cigarette pocket size QRP transceiver and a larger shirt-pocket transceiver.

An interesting article on basics about Baluns, intoducing the skin effects on radio frequency currents and its effects on receiving and trasmitting article by VE7FO

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

The MiniTioune receiver project, developed by Jean-Pierre F6DZP, consists of the home constructed MiniTiouner hardware which interfaces via a standard USB 2.0 port to a Windows PC running the MiniTioune software. It can be used to receive satellite broadcasts transmissions making it ideal for use on Q-oscar 100 Es hail-2 without any external frequency converters.

Building equipment for AMSAT P4A geostationary Es’hail-2 Quatar OSCAR 100 Satellite

Artwork Created in Verve by Michael A. Maynard K4ICY includes some nice amateur radio related paints

Getting started on receiving the QO-100 satellite using standard satellite LNBs and a 60cm dish

Annual poll for radio amateurs – the good, the bad, the ugly! This is an annual survey conducted among the online community, and it represents the status of amateur radio. The authors ask to hams several questions, from the most used operating modes, to the typical ham radio lifestyle habits.

Hairspray-can EH Antennas for shortwave and online programs. Small magnetic (H) antennas (Loops) have a good efficiency for the upper bands (20/15/10 meter band) and also in contrast to E-antenna a defined radiation direction.

The build was an experiment to see if a tube receiver could be stable enough to receive digital shortwave radio broadcasts. The tube acts as both an oscillator and mixer, so the receiver is a type of direct conversion receiver.

This KX3 go-box weights 1,6 kg including the components and the KX3 with its ATU and filter-option installed (no internal batteries) and a light-weight headset

DMRconfig is a free utility for programming digital radios via USB programming cable. DMRConfig support several DMR transceivers by TYT, Baofeng, Anytone, BTECH, Zastone, Radtel.

Amateur Radio enthusiasts who are interested in the LF and MF bands may be familiar with WSPR and WSJT JT9. Used as a propagation probe or beacon, WSPR allows very weak signals to be detected, frequently as weak as -27dB SNR.

Learn morse code with this online version of the popular morse machine. This version is currently working on Chrome browser only. This program teaches you to receive Morse code. It starts with a few letters and adds more when it sees that you are ready.

This online web application allows you to train the decoding of Morse code by copying random QSO sentences that can be looped or even mixed.

Send and receive wireless messages adding a small 433MHz radio to your Raspberry Pi, without the need of a WiFi connection and operate remote-control main sockets

FSQ is a Fast Simple QSO mode designed specifically for HF. It works well under NVIS and sunrise/sunset conditions on the lower bands, and also works well for short skip and grey-line on higher bands and can be used also on VHF FM.