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Simple implementation of the ARRL Antenna Book design equations for the axial-mode helical antenna.

Dire Wolf is a software soundcard modem and APRS encoder/decoder. It can be used stand-alone to receive APRS messages, as a digipeater, APRStt gateway, or Internet Gateway (IGate). It can also be used as a virtual TNC for other applications such as APRSIS32, UI-View32, Xastir, APRS-TW, YAAC, UISS, Linux AX25, and many others.

A one-tube battery-powered regenerative receiver.

Remote Control Antenna Switch made with two circuits board

SIGINT Systems. Provides the Harvester database system, a professional SIGINT Collection toolkit for radio enthusiasts.

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.

Ham Radio T-Shirts, Caps, Mousepads, also vintage designs! Designs include logos from Amperex, Collins, Eico, Eimac, Gonset, Hallicrafters, Hammarlund, Heathkit, Johnson, Knight, Mars, National, Swan, Skywarn and others.

A ranking of receiving antennas based on noise being evenly distributed in all directions. These rankings are most accurate in the frequency range of AM broadcast, 160 or 80 meter bands

Our company provides quality QSL printing service for affordable prices.

This amateur radio world map resizes the countries based on the number of licensed operators

A reference matrix of Kenwood Microphones by models with connector specifications and transceiver compatibilty.

For radio amateurs engaged in propagation studies and DXing on the 6-meter band, understanding the distribution of active beacons is crucial for assessing band openings and signal paths. This resource presents a static map compiled by _Carl-Axel Lindberg, SM6NZV_, illustrating the geographical placement of European beacons operating on the 50 MHz band, which is vital for monitoring sporadic-E, F2-layer, and other propagation modes. The map, last updated in April 2002, serves as a historical reference for beacon locations, allowing operators to correlate observed signal reports with known beacon positions. While not real-time, it provides foundational data for analyzing past propagation events and understanding typical beacon coverage areas across the European continent. Operators can use this information to identify potential receive stations or transmit points for future _DX contacts_ on the _Magic Band_.

Solution to your OEM needs and can meet your design or vended antenna requirements for antennas from 400MHz to 10 GHz.

QRPme offer QRP kits, tuna tin kits by W1REX

A 2-way remotely operated HF antenna switch, based on an idea supplied by G3YEU

These pages are entirely devoted to the Kenwood TS570 series Transceivers. Specifications & Brochure, Pictures, Schematics, Reviews, Manual and Modifications.

The DXrobot, operational since 1999, offers a free, non-commercial service primarily for the VHF ham radio community. It specializes in automatic real-time E-skip warnings for **144 MHz** in both Europe and North America, delivered via email or SMS. Additionally, the system provides automatic aurora alerts for _50, 70, and 144 MHz_ openings through the same notification methods. Beyond real-time alerts, the DXrobot facilitates the reception of the latest DX-cluster spots via email, a feature useful for operators without immediate WWW or cluster access. The service also displays recent E-skip and aurora spots detected by the DXrobot on 50, 70, and 144 MHz, with updates every five minutes. Historical data includes lists of all DX spots from the previous day on 50, 70, and 144 MHz, updated daily. Key propagation data, such as MUF timeline, Solar X-rays, Geomagnetic Field, and Estimated Kp index, are also presented.

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

Amateur Television (ATV) operations, particularly within the Arizona region, require dedicated resources for technical information, operational guidance, and community engagement. This club provides a focal point for hams interested in transmitting and receiving video signals on amateur bands. Members engage in local ATV repeaters, participate in technical discussions, and share knowledge on video modulation schemes, antenna designs, and station configurations. The club supports activities ranging from local simplex contacts to wider area repeater usage, fostering skill development in this specialized mode. The organization maintains a roster of club officers and offers membership opportunities to local amateurs. It also curates offsite links to other ATV resources, expanding the knowledge base available to its members and the broader amateur community. The club's emphasis on ATV helps propagate interest and technical expertise in a mode that combines traditional RF engineering with video technology.

mods for the Yaesu FT-100 by radiomods.co.nz

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.

Tombone VHF antenna for 146 MHz ad designed by YB8EIP

Here is how to adjust this popular tuner circuit so it transfers maximum power to your antenna without going snap

Great pages about KB1SG rhombic antennas collected by EI8IC.

A vertical half-moxon for the 7 Mhz by F6IRF

The Fan dipole antenna offer a easy to setup and efficient HF multiband antenna that does not require tuners or antenna switches, diagram by YC8PVU.

Allow 9 bands and 1300 Watt output on the TL-922 amplifier with this document by PA0FRI

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!

List of commnly used abbreviations in radio telegraphy communications

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.

Summarizes a portion of the FCC rules 47 CFR 80.371(c) and 80.373(f)

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

Build yourself a postage stamp 40 meter wire dipole antenna that fits in a space a little over 20 wide and works reasonably well at low heights

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

A very compact receive antenna made with ferrite bars by PA0FBK

F5RDH project of a transverter, that can receive input in HF and convert output to 144 Mhz in french

An easy to build spectrum analyzer

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

K6SGH introduce the hamloop antenna L7 series

Ham Radio 20 / 40 meter short Coax Trap dipole antenna designed with the coax trap design calculator program

A quarter wave vertical end-fed antenna for the 40 meters band. As all vertical antennas, also this aerial requires a good earthing system. In this project the ground is composed by twelve 4, wires buried in the lawn by using a spade to create a slit to drop the wire into.

A multiband antenna that can work from 80 to 10 meters in this illustrated docuemnt by G8ODE

A simple antenna that can be erected very fast, only need one center support, and do not take up much storage room. Works from 40 to 10 meters band

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.

Radio Norway International web site

Amateur Radio Dealer in Germany dealer for Icom Kenwood Yaesu Alinco and more.

This program simulates a HF link, using sound card and WIN95 by Michael Keller, DL6iAK