Наиболее удачные публикации по радиолюбительской тематике во всём мире за неделю — в обзоре ТОП радиолюбительских ресурсов. Этот обзор полезных интернет ресурсов представлен как выпуск лучших радиолюбительских сайтов недели «Top Amateur Radio Websites – Issue 1815».
См. лучшие сайты радиолюбителей — Выпуск 1815:
The Japanese-made Maldol MFB-300 HF vertical antenna offer extremely wide-band performance, with a specified frequency range of 1.0-60 MHz.
Free windows world map application display current time, sunrise and sunset, greyline map, dx stations, requires windows 7 or higher. The program includes three resized Natural Earth maps which have been resized to 4k or slightly less. By Simon Brown G4ELI better known as the inventor of Ham Radio Deluxe.
NVIS antennas, also known as Near Incident Vertical Skywave antennas have a high angle of radiation. Something on the order of 60 degrees, to straight up to 90 degrees. A portable, easy to setup and cheap nvis antenna project.
Portable, outdoor, trail friendly, low power HAM radio transceivers and kits for sale
Introduction to NVIS antenna and NVIS propagation. A simple NVIS antenna can be constructed as shown in this article
A homemade VHF/UHF vertical antenna made essentially with RG58 coax cable, with a 9 turns choke balun to prevent the shield acting as a RF Radiator.
DXCluster spots rendered on a Real-Time Azimuthmal Map centered on a custom callsign
Sort of similar to the one of the 6m omni. Instead of using twin-lead, this design makes use of a more or less regular double bazooka antenna (coaxial dipole). Your attention shall be drawn to the available standart literature, such as Rothammel. In order to “compute” the dimension, Karl Rothammel mentioned that the total length of the dipole shall be 95% of the free-space wavelength. The short-circuit bridges (closing the folded dipole) are to be placed at a distance-fraction being equal to the velocity factor of the coax cable used, which will be 66% using RG-58 or RG174.
Inches and meters Javascript Wavelength Calculator allow to input a frequency in MHz and calculate wavelenght in several units considering also fractions of wavelenght and the velocity factor. Includes an usefull inch to meter converter
How to limit unwanted harmonics from your raspberry Pi radio transmitter by introducing filters.
Project for DXers and experimenters alike. An old article publishes by 73 Amateur Radio magazine in PDF format, where all the components required to build your own HF spectrum analyzer may be found in a well-stocked junk box.
A 2m 70cm Dual Band J-Pole antenna for 35 USD. An excellent performing J-Pole type antenna, constructed from readily available materials.
A home made end-fed half-wave antenna coupler with antenna lenght calculator and counterpoise calculator based on center frequency. Includes pictures and drawings along to antenna homebrewing instructions with a home made on air wound transformer
A page describing how to setup a magnetic loop antenna with the DIY Magnetic Loop Starter Kit produced by Chamaeleon Antenna. Includes a video and a detailed instructions to setup.
An end-fed half wave antenna matching unit made of 3:24 turns ratio on a FT140-43 toroid with a 150pF capacitor across the input.
This is a Solid State Amplifier Project. It uses 4 MRF150 MosFet Power Transistors. The Power Supply Voltage is 50 VDC at 21.5 Amp. The max power available is 1,075 Watts. The Efficiency is about 65% +/- and runs Class AB Solid State.
A selection of speakers or headphones for use with amateur radio equipment. Includes an interesting paragraph comparing Dynamic and Electret Condenser Microphones, but also about audio Equalization.
An interesting article about a homemade LiFePO4 battery pack for ham radio operations, a 10Ah LiFePO4 based on Headway 38120 Cells
Bobcalc is a simple windows software to calculate the air core coils, the most widely used in RF circuits and may use the software to determine the data to build a coil, knowing that the inductance of this coil.
The ultimate Keyhole Markup Language (KML) plugin for Google earth. Keyhole Radio is a unique and powerful RF planning interface, accessed by loading a Keyhole Markup Language (KML) overlay in Google earth.
A polarity checker is a very useful item to have around the shack and in a go-kit. This project, inspired by a QST article on powerpole connector protection illustrate how to build a polarity checker.
A guide to choosing the right hardware and a guide on how to install DXSpider on a Raspberry Pi3. This article include a video and a PDF guide about the installation.
Batteries for portable radio operation are always an interesting subject for discussion. Review of some LiPo (Lithium-ion polymer ) batteries for amateur radio use.
