An excellent guide to homebrewing multi band end-fed antennas. The article, embed several drawings including diagrams and detailed pictures, illustrating the basic funcionality of end-fed antennas. The author gives some basic hints on how to build a half size antenna for 80 40 to 10 meters and a 6 meter to 40 meter configuration. It is also well described how to build the impedance transformer and the loading coils for lower bands.
A very well done presentation about End-Fed Half-Wave antennas. This PDF document contains a summary of experiences in how to build custom EFHW antennas. Includes an interesting comparison table of UnUn configurations with recommended toroids, Wire size, turns and capacitors. An useful recap on common errors in building homebrew EFHW Ununs completes the document.
The program can be used to calculate inductors (coils) and their number of turns on ferrite cores, ferrite shells and air coils. These can be used for baluns, Ununs, bandpass filters, low pass filters, resonant circuits, and more. The technical specifications of the cores are already integrated in the program. Application is free and runs on Windows 32 bit versions only. To make it run on Windows 10 64 bit need to be unzipped in a single folder.
Excel spreadsheet that help calculating dimensions of a high efficiency magnetic loop antenna for HF bands. Giving in input the loop perimeter, loop diameter and loop conductor will calculate electric characteristics, bandwidth, and efficiency
The antenna handles 250 watts and covers 40 through 10 meters, with an optional add on coil for 80 and 60 meters. The author in this pages includes an interesting video in which describes the antenna setup, and the importance of the shunting coil on lower bands like 40 and 80 meters. SWR curves diagrams are also included and demonstrate the influence on resonating frequency of the shunting coil.
An inductance and capacitance meter, measuring range is from 0 to >0.1uF for capacitance and 0 to >10mH for inductance. A project by Phil Rice, VK3BHR
Log Online of the DX-Pedition to The Order of Malta’s Italian Relief Corps (CISOM)
Personal web site by Joe PS8ET an active amateur radio operator from Brazil very active both on HF bands and on Ham Radio Satellites.
This unique online tool helps Ham Radio operators to choose the right rotator for medium and large HF antenna systems. The algorithm implemented in this calculator is the result of 40 years of experience in the HF Antenna sector. Given the Wind Speed, the total antenna square area, and the boom length, it will return the calculated torque value.
A tutorial on how to setup a receiver capable to decode SSTV signals with a small RaspberryPi version 2 and a RTL-SDR dongle. The author explains how to install the needed software to interface the RTL-SDR and a step by step guide to install the QSSTV software used to decode the signals.