A Combination CW Keyboard and Paddle Keyer. It uses a single Atmel microprocessor, the ATmega328P from the AVR family, and a 4 row by 20 column LCD display module.

An end fed antenna winder design that also contains the necessary matching toroid. This would be just the thing to throw in your backpack for portable operation.

This antenna build was strongly inspired by the well known PAR end fed antenna. The matcher box uses a T82-43 Fair-Rite core.

Three cell Lipo batteries for the FT-817 work really well, although not really sure about taking them on aircraft. The Lipos intended for use on RC Electric airplanes generally have a very low internal resistance and no internal protection against short circuit.

Helix antenna 432/435 MHz 14 turns. This 50 ohm impedance antenna allows, when fed with 25/50W of SSB RF, to join the orbiting satellites like AO-40 and AO-10 very easily

Adding a custom GPS receiver to the Yaesu VX-8DR

Kenwood TS590 memory management software for windows

Spitfire Collinear Arrays for 160 meters band at UA2FW

Article on portable HF antenna where author diverge about antenna efficiency versus size based on his personal experience on using HF antennas during portable operations

Comparison of Kenwood Ts590 v Elecraft K3. Comparing the TS590s to the Elecraft K3 as far as ease of use, receive characteristics etc. Forum thread at QRZ.com

A complete set of pages about the Yaesu FTDX3000 Yaesu transceiver, including USB Driver informations, voice keyer details, complete menu group informations, remote control and CAT control program, SDR Play and FTDX3000 configuration, firmware links and manuals

Kantronics Pinouts with information on Icom, Kenwood Motorola, Yaesu and Vertex radio connections.

How to verify what Com Port you have on your computer running WIndows XP or Windows 7. Installing the Proper New Prolific PL-2303 Drivers and how to verify the prolific drivers are correctly installed.

Make your own programming cable for the Kenwood TH-F7E handheld transceiver

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

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.

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

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