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DSCdecoder decodes the DSC digital signals from ships and coast stations using the sound card in your PC. You need a suitable MF, HF or VHF band radio receiver tuned to one of the DSC distress and calling channels or to one of the Navtex channels

The document is a PDF detailing the construction of the DBJ-1 VHF-UHF Dual Band J-Pole antenna for amateur radio use. It provides instructions on how to build a high-performance dual band base antenna for VHF and UHF bands using a single feed line for less than $10.

A small transmitting loop antenna for 20 metres using a aluminium bicycle wheel rim.

IR-DX HQ website

Amateur radio Services by the Federal Communications Commission.

Mods and articles collected by mods.dk

UHF 3 element portable antenna with gamma match by ON6MU

Psk31 program for Linux, supports up to four simultaneous receive windows.

Demonstrates an online **CW** audio decoder tool, currently under active development, designed for analyzing and decoding Morse code. Users can upload audio files containing Morse code or record live audio input via a microphone, with processing handled entirely in JavaScript using the Web Audio API. The software analyzes the audio, attempting to determine the pitch and speed, and then decodes the message, providing options to compare the decoded output against a predefined message or a perfectly timed version. The interface allows for setting optional comparison messages, character speed in WPM, and Farnsworth speed. It also features interactive charts for visualizing the audio analysis, where users can zoom with the mouse wheel and pan by dragging. Specific buttons highlight different element types such as intra-character space, inter-character space, extra elements, missing elements, and replaced elements, aiding in detailed signal analysis. Built-in test files are available for immediate analysis, allowing users to quickly evaluate the decoder's performance. The tool is noted to work with specific browsers and is presented as a testing platform for user feedback, indicating ongoing refinement of its decoding algorithms and user interface.

Freeware real time DSP filter particularly for applications of amateur radios , IIR, FIR filter, low-pass, high-pass, band-pass filter, band suppressor (notch filter) individually adjustable

An HF QRP CW RTX built around the Arduino open-source electronics prototyping platform

MMVARI is a multi-Mode SoundCard Ham (Amateur) Radio program for receiving and transmitting the RTTY-PSK-FSK-MFSK modes. The program was written to experiment with the efficiency of transmitting Japanese and East Asian languages (HL/BV/BY) using the VARICODE

The AZIMUTH program plots a world map in either azimuth (beam heading) or Mercator projections. If you specify your home location in latitude and longitude, the azimuth projection is centred on your location. The Azimuth map program can display Maidenhead grids - this is useful for 6m, 2m, and UHF DX communication display. Various features of the map are: Azimuth or Mercator projections , Maidenhead grid display, Simple map zooming, Print maps with adequate resolution up to one meter sized map

Excellent guide to using ferrite cores for interference suppression. Understanding and Solving RF Interference and Noise Problems by Jim Brown K9YC Audio Systems Group, Inc. PDF File

An old satellite frequency list from 3 to 8475 Mhz dated 1996

Calculating and building an Eggbeater antenna. InstantTune and push-button Rx. Documentation available in french and english

This tower is easy and inexpensive to build and easy to disassemble for transport.

Acars reformatting and route plotting program

General Mobile Radio Service Frequencies

This project shows how to build a 50-ohm dummy load using non-inductive resistors, oil for heat dissipation, and a simple assembly process. It enables accurate transmitter tuning, testing, and power measurement across LF to UHF bands. The setup allows meter calibration by measuring peak voltage, applying diode drop correction, and calculating RMS voltage and power precisely. Parts are inexpensive and widely available. With proper assembly, this dummy load offers extended service life, accurate readings within 2%, and a reliable alternative to costly commercial wattmeters for amateur radio applications.

Win96 - data management software for the PRO-96 digital trunking scanner

Online Catalog & storefront (NJ) sales of amateur radio & related items.

hamOS is a live and installable Debian based linux respin for Amateur Radio Operators. It is intended for new users with little or no linux experience. hamOS contains a variety of pre-installed applications for amateur radio like logging, homebrewing, digital modes, and more.

Over 40 years of experience inform the reviews and commentary presented on Dave's Radio Receiver Page, covering a wide array of radio receivers and transceivers. The resource details specific models such as the **ICOM IC-R8600** SDR Communications Receiver, which is lauded as Icom's best wide-band receiver, even surpassing the IC-R9500 in performance. Other notable reviews include the ICOM IC-7300 HF Transceiver, highlighting its direct sampling SDR technology and spectrum scope capabilities, alongside numerous models from Japan Radio Co. (JRC), Kenwood, Yaesu, and various portable shortwave receivers. The content provides practical insights into the performance and characteristics of each radio, often drawing comparisons between models. For instance, the early issues with the AOR AR7030 receiver's Bourns mechanical encoders are thoroughly documented, including AOR's eventual switch to higher-quality Alps encoders. The page also features reviews of antennas like the MFJ-1026 Noise Canceling Signal Enhancer and various power supplies, offering a holistic view of radio monitoring setups. The author's "2 ear / 2 eye method" emphasizes real-world listening experiences over laboratory measurements, providing a unique perspective on equipment utility.

How connect a common PC headset with microphone to the Yaesu FY-817, FT-857, FT.897 in italian by I6IBE

Comprehensive list of beacons in the 50MHz band maintained since 2013 by G3USF.

buy and sell a diverse inventory of Navy, Army, USMC, Air Force, Coast Guard and home front related items from WWI through Vietnam.

Version 1.4.6 of _AAVoice_ functions as a digital voice processor for amateur radio, designed to operate on Windows platforms from 9x through 10. This software leverages pre-recorded WAV files for transmission, allowing operators to send pre-defined messages or calls efficiently. Its core functionality includes PTT control, which can be managed through a simple circuit connected to a COM port, providing a reliable interface for radio keying. The program offers extensive macro capabilities, streamlining repetitive transmissions during contesting or DXing. It also features direct integration with the _AALog_ logger, enhancing workflow for those using DXsoft's suite of tools, and can interface with other compatible programs via its COM-interface. Author Alexander Anipkin designed _AAVoice_ to require a working sound card, and it comes with a basic set of sound files. Users can easily create additional WAV files using standard Windows sound recording utilities, ensuring flexibility in customizing audio content for various operating scenarios.

Yaesu FT-817 Portable QRP MF/HF/VHF/UHF Transceiver, an assortment of technical information

Design your own quadrifilar helix, the site even generates a drilling pattern in a PDF file. Several different construction methods are shown.

Real 4:1 Transmission Line Balun with Balanced Load

The ZS6BKW multiband HF antenna, a design by ZS6BKW (G0GSF), functions effectively on multiple HF bands without requiring an Antenna Tuning Unit (ATU) for 40, 20, 17, 12, 10, and 6 meters. This antenna, approximately **27.51 meters** (90 feet) long with a 12.2-meter (40-foot) open-wire feeder, is a direct descendant of the _G5RV_ but offers superior multi-band resonance. It can be deployed as a horizontal dipole or an inverted-vee, with the latter requiring only a single support and maintaining an apex angle of at least 90 degrees to prevent signal cancellation. Performance data, recorded with an MFJ Antenna Analyser, indicates SWR values of 1:1 on 7.00 MHz (40m) and 14.06 MHz (20m), with SWR below 1.3:1 on 17m, 10m, and 6m. While primarily designed for these bands, the antenna can be adapted for 80m, 30m, and 15m with an ATU, preferably at the balanced feeder's base. The use of 450-ohm twin-lead for the feeder is recommended over 300-ohm for improved strength and reduced losses, especially in adverse weather conditions. This design, originally published in _RadCom_ in 1993 and featured in Pat Hawker’s "Antenna Topics," provides a compact and efficient solution for HF operation, particularly for those with limited space or resources.

A Site to help you get started in QRP, including building your own QRP radio.

University of Texas Amateur Radio Club RF-Calculator. This is a main beam power density estimation program intended for use as part of a routine evaluation of RF safety compliance with FCC regulations

Modifications, improvements and setup of the Yaesu FT-2000 at DK3HV

Linking VHF and UHF radios and repeaters around the world using a secure Voice-Over-IP system, with no hackers!

William Hepburn's Daily Tropospheric Ducting Forecast.

The G3TPW Cobwebb antenna covers five bands, 14 - 28 mhz, including the WARC bands

An adjustable VSWR, 2 meter J-Pole

RadioReference.com, scanner frequency and radio communications reference source, with complete conventional frequency assignments, trunked radio system information, frequencies, and talkgroups, FCC License assignments and maps, 10-Code Lists, agency maps, files, downloads, links, and detailed agency information for most public safety, military, and local government activities.

AEA Technology Inc. is a pioneer and leading manufacturer of RF and cable test equipment for the wireless, Telco, CATV, NMR & MRI, RFID, telemetry, aviation, commercial, military, and two-way radio industries. Produces SWR Meters, Pre Amplifiers, filters, power meters and antenna testing products

K0JD's home construction projects, featuring the R2/T2 modules by KK7B

WA5FRF VHF mobile antenna for bicycle installation

Turn your android mobile phone or tablet into an affordable and portable software defined radio scanner

Pictures and homebrew instructions for this collinear 2.4 Ghz antenna

A prototype 2.45ghz antenna for mobile use. This antenna has been u sed for surveying signal strength using a variety of free wlan tools.

DarwinPsk is free to licensed ham radio operators and is a great application for PSK and RTTY communications under MacOSX

Crossed yagi for 437 MHz Satellite antenna, with power divider splitter build.

The Petlowany Three-Band Burner is a simple, low-cost, trapless short vertical antenna which amazingly works on three HF bands (20, 15 and 10 meters). This web page contains pictures, performance data, and enough construction details so you can homebrew your own.

With over 400,00 vacuum tubes in stock, ESRC is a major supplier of tubes for commercial and hobbyist purposes