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MorseMaker is an up-to-date replacement for the Morse Machine shown further down this page. It has been re-written using a different programming language and is now entirely 'stand-alone' requiring no run-time support files. This version also works with Windows XP and can use the soundcard but please note that, unlike its predecessor, it does not split the alphabet into smaller 'learning' blocks and does not incorporate the Morse reader.

Proppy: Online HF propagation predictions using the ITU Recommendation P.533-13 Propagation Prediction Application.

This circuit provides an interface between the Yaesu 920 transceiver and IBM computer sound card which allows data transfer and control of PSK31, RTTY, KEYBOARD CW, and SSTV modes for Amateur Radio

Microphones, headsets and accessories for amateur radio and professionals

Setting up and testing a sound card packet radio interface by KD5ZUG

Article on PC to radio interfacing by Paul Umbdenstock, WA1VOA

Deciphering weak or noisy **CW** (Continuous Wave) signals often presents a challenge for amateur radio operators, particularly in contest environments or during DXpeditions. CWLab04X addresses this by providing a software solution that leverages **DSP** (Digital Signal Processing) capabilities of a soundcard to decode Morse code. It functions as both a receiver and a sender, supporting traditional CW and a unique "CCW" mode designed to enhance copyability of signals struggling against high noise floors. The program offers two installation methods: a Windows-specific installer for straightforward setup or a zipped package compatible with Windows and Linux systems running Wine. Users must first download and review the accompanying PDF documentation, CWLab04.pdf and CWLab04_Hardware.pdf, which detail the software's operation and the necessary soundcard interface circuit. The hardware PDF outlines a direct connection from the receiver audio output to the soundcard input, with optional conversion of the soundcard output for hard-keying or microphone input. CWLab04X is intended as an operational aid rather than a replacement for skilled human copy, particularly highlighting the effectiveness of its CCW mode in adverse signal conditions. The software was last revised in April 2009, with installation requiring the LV Runtime 602.

Have you ever wanted to listen in on a serious SO2R DX contest effort? hear what the low bands sound like from New England? enjoy a contest without having access to a radio? This is your chance!

Morse Pilup Audio tapes available also in Real Audio format.

Learn the Morse Code. Learn from random text or simulated QSO (contact) sources. Create character sequences that you find difficult. Compare your results with what the program sent and view error statistics. Take simulated tests. Sound card not essential. Evaluation version not time limited.

CWRX, a freeware Windows application, decodes Morse code (CW) signals directly from a sound card's audio input, presenting the decoded text on screen. It supports various receive bandwidths and filtering options, allowing operators to optimize signal reception in different QRM conditions. The program's core functionality focuses on robust CW decoding algorithms, crucial for weak signal work and contesting environments. Developed by OZ1IVA, Lars Harbo, this utility provides a straightforward interface for real-time CW interpretation. It integrates basic logging capabilities, enabling users to record decoded transmissions for later review or contest submission. The software is specifically tailored for the Windows operating system, ensuring compatibility with common shack computer setups. Its design emphasizes ease of use for amateur radio operators seeking a dedicated CW decoding solution. The program's small footprint and direct functionality make it a practical tool for both casual listening and more intensive operating sessions, without requiring extensive system resources.

A Simple Serial and Sound-Card Interface for the Yaesu FT-857D

SignalGen is a free (GPL) Linux (Xwindows GUI-based) utility that generates relatively low frequency signals with the use of a PC sound card. It is an entirely suitable replacement for a hardware signal generator if one doesn't require signals of a frequency higher than about 50 KHz. SignalGen creates any frequency between a fraction of one Hertz and an upper limit determined by your sound card's capabilities.

The resource provides a specific wiring schema for adapting a Kenwood PG-4S cable to be compatible with Kenwood TH-F6A, TH-F7E, and TH-G71 handheld transceivers. It details the necessary pinout modifications, illustrating how to convert the existing PG-4S cable, which is typically used for data transfer or programming, into an interface cable for these specific HT models. The content focuses on the electrical connections required to achieve this cross-compatibility, presenting a practical solution for hams who already own a PG-4S and wish to avoid purchasing additional dedicated cables for their TH-F6A, TH-F7E, or TH-G71 radios. The adaptation process involves reconfiguring the connections to match the audio and data port requirements of the target handhelds. This technical information is particularly useful for operators seeking to interface their Kenwood HTs with sound cards for digital modes or for programming purposes, leveraging existing hardware. The page offers a direct, functional approach to hardware modification, emphasizing reusability and cost-effectiveness for Kenwood transceiver owners.

Chip64 mp3 file

Windows open source packet radio decoder. Decodes AFSK1200, AFSK2400, HAPN4800, and FSK9600 packet data with a radio connected to your pc sound device.

This program demodulates the telemetry data signal transmitted by the AO-40 satellite (aka Phase III-D) using the PC sound card

This is a packet radio software developed for amateur radio operators to provide IP communications. You can chat, send/receive e-mail, surf the web and so on via radio depending on your bandwidth. You don't need a TNC. You might have all of TNC features via SoundCard using SoundModem.

Processing a single RTTY signal from a transceiver's 3-kHz audio, GRITTY employs _Bayesian statistics_ for superior decoding accuracy compared to traditional trial-and-error methods. This approach not only decodes 5-bit Baudot codes but also calculates the probability of error for each bit, enabling features like color-highlighting unreliable characters and smart squelching based on error probability rather than signal amplitude. This allows decoding of very weak signals while suppressing strong, undecodable interference, resulting in minimal garbage text. The program intelligently analyzes decoded text, comparing similar callsigns bit by bit and merging probabilities using the Bayes formula. This often allows GRITTY to determine the correct callsign and place it on the call stack even when all received copies are corrupt. The same methodology is applied to correct errors in exchange numbers and CQ/DE keywords, and to fix incorrect shift states. GRITTY offers an open API interface, documented in its Help file, for integration with other programs, allowing them to receive decoded data and mouse click events.

Information and digital audio samples of various modem modulation types

The KK7UQ computer to radio interface, sound card interfaces, IMD meters interface products

Few recordings of difficult qso's

Generates dial tones using the Soundcard. A neat tool for sending out short sequences of DTMF tones.

Audio and waterfall images of some sounds found on the RF spectrum

Sounds of Space Weather by S. McGreevy, N6NKS

PTT and soundcard interface schematic by ON6MU

IC820H or other Icom Radios Soundcard interface for VHF EME use by DF9CY

The Peaberry SDR is the first and only do-it-yourself transceiver that doesn't require adding sound cards to your computer.

Need to interface both a TNC and the computer soundcard? This is a ICOM 756PRO ACC1 audio/keying/FSK interface by WA0SXV

VoiceKeyDeluxe (VKD) will convert your sound card into a powerful and versatile digital voice keyer for contest or EME operations by N7QJP

Useful pages of longwave operations, includes a lot of reference files, beacons list, sounds and pictures

Adjusting audio output of your soundcard to obtain a perfect PSK signal from your transmission. A project to help you tuning your PSK31 emission.

Sound Byte is a voice keyer for contests as well as general ham radio use. Windows and Mac, commercial by Black Cat Systems

This interface is intended to be used with all the popular digital modes like PSK31, RTTY, Olivia, etc., which modulate a continuous carrier.

Echolink, EQSO, Echostation, SSTV, WEFAX, PSK-31 other digital sound card modes

Description, frequencies and sound samples of most popular amateur radio digital modes by DG8FBV

Amateur Radio Projects & Kits for homebrewers, includes DDS,sound card interface,programmers, hamcom, frequency counter, RF Power Meter, modems and more.

Generates Morse tones using the Soundcard. A neat tool for sending out short sequences of Morse tones.

The SDR-908 is a software defined radio designed specifically for portable use, without the bother of being tethered to a PC or soundcard for the modulation/demodulation processing performed in this kind of radio.

Beacons recorded audio files by kl7fdq

A morse tutor that drives any Linux supported soundcard.

DarkIce is a live audio streamer. It records audio from an audio interface (e.g. sound card), encodes it and sends it to a streaming server. Works on Linux and MacOSX

Audio files to help identify rf noise (rfi). Identify the RFI that interferes with your reception. RFI Noise identification.

Sound Card Interfacing for RTTY, PSK31, and SSTV

The Elecraft K2 transceiver requires specific modifications for optimal soundcard digital mode operation, particularly for PSK31. The original article, circa 2001, details initial challenges with manual PTT and speech compression settings. A key modification involves adding headphone audio and a compression disable signal to the K2's microphone jack, utilizing pins 4 and 5. The **COMP0** signal, active low, is shorted to ground via a non-inverting open collector switch circuit, comprising two resistors and two transistors, mounted on the SSB board near U3. This circuit provides effective control of an analog signal line with good noise immunity. The switchbox itself repurposes a computer COM port switch, using only two of its original connectors and four of the nine poles. It integrates a microphone preamplifier, a PTT circuit built with 'flying leads' construction, and RCA jacks for soundcard connections. A trimpot adjusts the audio drive to the K2. The central DB9 connector links to the K2's mic connector via a shielded RS232 serial cable, ensuring proper grounding and signal routing. An external footswitch PTT jack is also included. Further enhancements include a **noise-canceling microphone** preamp based on a QST December 2000 article, adapted for Heil mic elements. This preamp, built with pseudo-Manhattan style construction, provides a gain of approximately 2 by changing emitter resistors (R9 and R16) from 680 ohms to 330 ohms. A 10-ohm series resistor and 47 µF capacitor on the +5V supply mitigate noise spikes.

This voice-keyer-interface connects between a Yaesu FT1000MP and a PC's sound card & COM port. It can be used as a voice-keyer with Contest Voice Blaster and as a voice-keyer and CW-keyer with Writelog.

Located in the Owen Sound,Ontario area. Meetings are the 4th Tuesday of the month except for summer.

Some sound samples of received signals mainly on VHF-band

Dedicated to 50MHz and 144MHz. Online 2m and 6m logs. Real Audio sound clips of Tropo, Aurora, Sporadic E, Meteor Scatter, TEP and F2 Propagation.

Enhanced SSB Audio (ESSB) is a specialized operating mode that extends the capabilities of traditional Single Sideband (SSB) voice transmissions. This presentation by K4QKY delves into the technical aspects of ESSB, discussing its advantages and the ongoing debates within the ham radio community regarding audio quality and bandwidth usage. ESSB aims to provide clearer and more natural-sounding audio, which can enhance the overall communication experience for operators. The presentation covers various topics, including microphone selection, audio processing techniques, and the importance of proper equalization. It also addresses the controversies surrounding ESSB, such as the potential for interference and the debate over whether it strays too far from traditional SSB practices. By understanding these elements, amateur radio operators can make informed decisions about their audio setups and contribute to discussions about the future of SSB operations.