digital voice

Antena Multibanda Colinear para HF - A W5GI antenna description in spanish

EC2APU multiband wire antenna - Wire antenna for 10-15-20-40-80 meters band, with many drawings and description in spanish

Granta Contest Group - HF amplifier - The Granta Contest Group was founded in 1997 by Mark G4AXX, Colin G4CWH, Simon G4EAG, Andy G4KNO. The Group gets it's name from the River Granta (or Cam), which passes through Cambridgeshire and Essex. Using is a 160-10m "desktop kilowatt" linear amplifier using an Eimac 4CX1000A tetrode

Trusted QSL - The mission of the Trusted QSL Group is to keep eQSL an open and free activity for amateur radio operators by promoting the Digital Signature Standard (DSS).

TwinsLAN Amateur Packet Radio Club - TwinsLAN is Minnesota's only amateur radio club devoted to digital communications

Digital modes sounds - Ever wonder what all those funny sounds are that you come across from time to time on the ham bands

Digi Mode Sound Files - Mp3 and wav files linked from this page are intended to help your understanding of what the different digital modes sound like

AOR U.S.A., INC. - Aor u.s.a web site, manufacturer of base and mobile receivers, handheld receivers, digital voice modems, spectrum display units, frequency monitors and antennas

I-LinkBoards.com - Echolink, EQSO, Echostation, SSTV, WEFAX, PSK-31 other digital sound card modes

Unified Microsystems - W9XT contest card DVK Digital Voice Keyer, morse keyers CW memory keyer, beacon CQ IDer, USB interfaces and more for ham radio operators

RFSM-2400 Digital Mode - A recent digital radio protocol. Based on a freeware soundcard-based Radio Frequency Software Modem. Work under standart MIL-STD-188-110A. Maximum speed 2400 bit/second. Signal bandwidth: 0,3-3,3 kHz (standard mode) and 0,3-2,7 kHz (non-standard mode).

Russia ATV Amateur TV - Digital Amateur Television web sited include a D-ATV transmitter, D-ATV receiver, D-ATV modulator D-ATV schematics by RA3TTS

A Flexible Digital-Mode Interface - One interface, all the software—here’s how to do it simplyand inexpensively. QST article by Jim Mitrenga N9ART

FDMDV - Digital Voice - FDMDV - Frequency Division Multiplex Digital Voice Digital Audio over HF SSB. FDMDV is the latest digital voice mode on HF - it caters to high quality digital voice under poor band conditions, in only 1100Hz bandwidth

EME with or without Signal Processing? - This page contains Contributions to a Discussion on the Moon-Net about the Application of Digital Signal Processing (DSP) Methods in Moonbounce.

Sound Card Packet - This amateur radio web site explains how to use the AGWPE utility program to send and receive packet (a digital data mode) using the sound card of your PC instead of a traditional TNC (Terminal Node Controller), a radio modem.

Voice Repeater Basics - Repeater operating is one of the most popular facets of amateur radio

Tait Electronics Ltd - Asia Pacific - Tait electronics provides advanced and reliable voice and data radio communications products and solutions, specialising in customised solutions for organisations worldwide.

EasyPal - Easypal is a freeware DSSTV software uses the DRM (Digital Radio Mondiale) encoding to allow the sending of image files over voice channels. This mode is known as Digital SSTV

DSCdecoder - 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

Trusted QSL - Open source libraries and utilities to support using digital signatures for Amateur radio QSL system information like eqsl and lotw. Available for windows macos e linux.

Voice descrambler - This program descrambles band inverted encrypted transmissions, usually found on VHF/UHF. It uses a NCO (numerical controlled oscillator) to re-produce the originally inverted audio band. Use it only if legally permitted in your country. I assume no responsabilities deriving from its use. Standard disclaimer applies

QuickMix - Freeware windows program that allows you to store configuration of your audio mixer in a settings file, and to restore the mixer to that state whenever you want. Useful for digital mode operations where different dsp programs may require different audio in and out settings.

A simple VOX circuit - Here is a 3 transistors 6 diodes circuit that is a Voice Operated Tx PTT control as well as an ANTI VOX circuit to stop mis-operation from Rx noise by G8MNY

Mac to transceiver interfaces - This article illustrate different ways to interconnect a macintosh with a transceiver in order to remote control radios and operate digital modes by Kok Chen, W7AY