Search results

Launching a balloon or kite supported tall vertical or protracted inverted L.

Picture and specifications for Yaesu VX-7R

This page describes a simple way to determine the main RF characteristics of a Wifi (IEEE802.11b/g wireless LAN) antenna.

ARRL index of document about trapped antennas and notes on traps usage

Article on rhombic antennas, radiaton patterns, disvantages, and more info on rhombic aerials

This doubet antenna is a half wave dipole antenna easy to build, in french

Experiments with phased wire vertical antennas on 40 meters at VA7ST

Presented here is a high-performance, circularly polarized omni-directional antenna that is easy to build, easy to tune, inexpensive, and will work all the mode J Low Earth Orbit (LEO) satellites

Presents the design and construction of the OK2FJ Bigatas, a portable, automatically tuned vertical antenna covering 80 through 10 meters. It details two distinct control systems: one utilizing BCD band data from Yaesu FT-857/897 transceivers, and another employing voltage level sensing for the Yaesu FT-817. The resource provides specific instructions for building the antenna's radiating element, loading coil with switchable taps, and the control circuitry, emphasizing the use of readily available components. The article outlines the physical construction of the antenna, including the use of duralumin tubes for the radiator and a PVC tube for the coil form. It specifies coil winding details, tap points, and the integration of radial wires for ground plane operation. The control electronics section provides schematics and component lists for both the BCD decoder (using a 74LS42 IC) and the voltage comparator (using an _LM3914_ bargraph driver), enabling rapid, automatic band switching without the minute-long tuning delays common in other systems. Crucially, the antenna achieves rapid band changes, with typical SWR values centered on common operating segments, such as **3.7 MHz** for 80m SSB. It also discusses modifications for CW operation on 80m and the trade-offs between antenna efficiency and full-range automatic tuning on higher HF bands, where manual adjustment of radiator length is suggested for optimal performance on 15m, 12m, and 10m. The resource includes construction photos and a discussion of cable requirements for reliable operation.

Double bazooka antennas

HF pedestrian operation using loop antennas by PY1AHD

Articles and original manuscripts on RF power amplifiers

Windows freeware database containing frequencies, locations, and a small logging program capable or recording audio

Overview, summary, tutorial about the log periodic antenna or aerial used for wideband RF antenna applications

Vortex Antenna Systems, radio communication antenna aanufacturer and supplier of antenna related hardware. Ham radio HF and VHF Antennas, antenna parts, mast and mounts.

This workbook was developed to support training for the Goldstone-Apple Valley Radio Telescope, but is a resource applicable to all radio astronomy.

D-PRS converts these position reports from remote D-STAR radios to an APRS format. Windows .net application

A scanner resource for the Dallas-Fort Worth Metroplex including trunk information and a live scanner feed.

VHF Optimized Yagi Antenna for the 6-meter band (50 Mhz) by ON6MU

Linux-based amateur radio logging software, _CQRLOG_, integrates a Firebird database for robust data management and offers radio control via _Hamlib_ libraries. It provides essential features for DXers and contesters, including DX cluster connectivity, _QRZ_ callbook lookup, a grayline map, and support for the ON6DP QSL manager database. The application incorporates a country resolution algorithm, developed by OK1RR, which is noted for its accuracy in identifying DX entities. The software's design prioritizes operational ease and maintenance, making it suitable for active logging. Its country resolution algorithm, based on meticulously maintained country tables, aims to minimize errors in DXCC credit. The integration of _Hamlib_ ensures compatibility with a wide array of transceivers, simplifying rig control for various operating modes and contest scenarios.

Macintosh morse code software, Fast Morse will convert any text you enter into the original Morse code equivalent, and play it on your speakers. The speed can be adjusted to anything from 1 to 35 words per minute if your computer can keep up, allowing you to send Morse signals at a rate your friends and fellow Morse enthusiasts can follow!

FindU.com operates as a robust database archiving **APRS** (Automatic Packet Reporting System) data, including weather, position, telemetry, and message reports. It integrates data from both amateur radio APRS systems and the internet-based Citizen Weather Observer Program. This substantial 58 GB database is hosted on dual servers utilizing data replication, processing approximately 20 new reports per second to provide constantly updated information. The system supports various applications, such as displaying weather reports, tracking position data, and facilitating long-term vehicle tracking. A notable function involves forwarding over 100,000 near-realtime weather observations daily to the National Oceanographic and Atmospheric Administration (NOAA) for accuracy checks and use by NOAA and the National Weather Service. Additionally, it archives APRS reports from the International Space Station. Access to the database is primarily via dynamic web pages, with a comprehensive list of available CGIs detailed on a dedicated server page. While direct URL parameter editing is possible for advanced users, alternative web pages with forms simplify query submission. The platform utilizes **PNG** images for dynamic graphics, a choice made due to past GIF patent issues, ensuring broad browser compatibility.

An analysis of the cebik dipole and other small limited space dipoles fed with open wire ladder line.

Also known as Magnetic Loop Antennas, by AA5TB. Excellent article on construction tips and tecniques of a Small Loop antenna

Rhombic antenna for shortwave radio broadcasting, general description and radiation patterns

K6SGH introduce the hamloop antenna L7 series

This is an attempt to build an Antenna rotator controller using Arduino Mega 2560 with a nice user interface showing the actual position of the antenna.

Lets you listen to your scanner across your own network, or via the internet. Shoutcast/ICEcast compatible broadcasting for Uniden and GRE scanners. Broadcast your audio from your PC. ScannerCast is a specialized broadcasting solution that enables users to stream scanner audio feeds over the internet. This software supports both Uniden and GRE scanner models with tag information capability, while providing audio-only functionality for other scanners. Compatible with standard streaming protocols, ScannerCast allows remote listening via common media players without requiring specialized client software. The program features customizable tag display, adjustable bit rates, and seamless integration with Radio Reference. Its efficient design replaces multiple legacy applications while improving tag/audio synchronization. ScannerCast operates efficiently across various Windows environments, making remote scanner monitoring accessible from any location with internet connectivity. Scannercast is no more supported or developed by it's author.

Supplier of amateur radio equipment for 50MHz and above in New Jersey

Download chip64, freeware windows digital mode by IZ8BLY Nino

MARS, Israel's Antenna and RF System manufacturer, flat antennas for cellular, military broadband, multiband MF high power antenna

A 2.4 GHz WiFi antenna that can boost your WiFi signals for many miles. It\'s an easy to build Yagi antenna project done with some popsicle sticks, paper clips and glue.

A COM component for transceiver/receiver CAT control. Not a complete program, but rather a component tool that allow software developers to connect their program to a supported transceiver.

Display solar activity forecast for next 27 days, display A-index, Sunspot Numbers and Flux forecast including graphs for solar activity and geomagnetic forecast. All forecasts are updated daily.

Manufacturers of high performance low power am transmitter products: sstran amt3000, bc-100, and the mw-250. for home and professional use.

The National Radio Club is the world's oldest and largest Medium Wave DX club, founded in 1933.

Free Morse Code CW training software for Android supporting the Koch method by IZ2UUF David

Custom built amateur radio adjustable antennas and accessories. Screwdriver antennas, antenna controllers

A simple, cheap, efficient tv antenna that you can make yourself.

A 5/8 vertical groundplane antenna for 50 mhz

20m 2-element light-weight Yagi antenna

Hints about Jpole Yagi and Quad antennas

This project outlines the construction of a 3-element reversible quad antenna specifically designed for the 40-meter band. The materials required include pushup towers, pressure-treated posts, insulated wire, and various electrical components such as relays and a balun. The construction process is straightforward, beginning with the installation of the posts in a straight line, followed by the assembly of the antenna elements and their elevation to the desired height. The antenna's design allows for directional signal reception, making it ideal for operators looking to enhance their communication capabilities on the 40-meter band. The project includes detailed instructions on tuning the antenna for optimal performance, ensuring that operators can achieve the lowest SWR possible. Additionally, the design can be adapted for other bands by extrapolating dimensions, providing versatility for amateur radio enthusiasts. Overall, this reversible quad antenna project is suitable for both beginners and experienced operators, offering a practical solution for improving signal strength and directionality in 40-meter communications.

Designs and manufactures a comprehensive line of microwave communications equipment for television broadcast, video, telemetry, and electronic surveillance applications.

Orange County Sheriff Live Audio Feed at radioreference. Florida USA

Why 6 meter hams design the best antennas

A low-level voltage meter and could even be used for audio purposes.

D3+ High Performance Antennas for Field Day. This article describes versatile broadband wire antennas. These antennas will double your effective radiated power over a dipole, will be easy and inexpensive to build and install, and will be simple to match.

Stream your radio audio output with free version on unreal media server. Support live audio and video broadcasting via internet

Band-pass filters can be critical components in competitive stations. This setup may help put your station on the map.