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SSTV freeware software for Windows by Mako JE3HHT. MMSTV is a free software application designed for transmitting and receiving SSTV (Slow Scan Television) images over HF bands. It allows radio amateurs to share still pictures using sound-card interfaces and a transceiver. The program supports popular SSTV modes (Martin, Scottie, Robot, etc.), real-time RX/TX monitoring, and easy image editing. Its user-friendly interface and reliability make MMSTV a favorite choice among ham operators worldwide. Ideal for showcasing QSL cards, shack photos, or technical diagrams over the ai An excellent SSTV program that requires only a computer with soundcard, no expensive TNC required. Works on all Windows version including Windows XP, Vista and Windows 7.

Demonstrates a comprehensive logging and contest program for Windows, _UCXLog_, designed to assist amateur radio operators in managing their QSO records and participating in competitive events. It integrates essential features such as transceiver control for single-operator two-radio (_SO2R_) setups, CW keying via COM/LPT ports, and SSB/RTTY operation through soundcard interfaces. The software also provides DX cluster connectivity via packet, internet, or Telnet, alongside robust statistics tracking for awards like _DXCC_ and _IOTA_, locator management, and greyline map display. Enables operators to efficiently handle log import/export functions, print QSL cards, and maintain detailed records of their contacts. The program's network capability facilitates multi-operator environments, while its support for various digital modes and rig control protocols enhances operational flexibility. Regular updates, including beta versions, are provided, ensuring ongoing development and feature enhancements for the amateur radio community.

Presented here is a transceiver to computer sound card interface complete with automated transmit key function. A sound card interface is simply the audio coupling of a computer soundcard and a transceiver to allow various computer applications that send and receive SSTV, RTTY, PSK31 and other similar modes based on soundcard generated signals.

SDR-RADIO.com is a Windows console for SDR receivers and transceivers. Designed for the commercial, amateur radio and short-wave listener communities, the console provides a powerful interface for all SDR users. Many SDR owners have made their radios available over the internet. Just look at the Web Servers page for a list of the radios you can use. You do not need a licence to use this sodftware with RFSPACE, FUNcube Dongles, Soundcard (SoftRock) and low-end SDRs.

MultiKeyer is a dedicated computer keying program designed for amateur radio operators engaging in specialized operating activities such as Earth-Moon-Earth (EME) and Meteor Scatter, as well as general contest operations. It provides distinct modes for both CW and Phone transmissions, enabling automated message sequencing and playback of pre-recorded audio files. The software's interface shares a similar "look and feel" to the popular WSJT Meteor Scatter/EME program, facilitating ease of use for operators familiar with that platform. For CW operations, MultiKeyer offers an EME Auto mode for sending timed messages crucial for EME and Meteor Scatter, alongside a Contest mode that handles automatic CQ calls and preprogrammed messages. On the Phone side, it features a Sequenced Phone mode for transmitting prerecorded .wav files during Meteor Scatter events and an Auto Phone mode for contest use. The program leverages serial COM ports for CW and PTT signaling, and the soundcard for .wav file playback, with configurable PTT interrupt options. MultiKeyer integrates with TRX-Manager for PTT and CW keying, and can send callsigns for logging. It also supports WSJT-style "callsign.txt" files for lookups and adheres to the SO2R protocol for parallel port connections. Designed for Windows 98 and NT, it generally functions on Windows 95, ME, XP, and 2000, requiring a 133 MHz Pentium-class processor.

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

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.

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.

PTT and soundcard interface schematic by ON6MU

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

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

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.

Computer Control and Soundcard Interface for the Icom IC 706

A simple PSK31/digital interface which can connect your transceiver to a PC soundcard for digital modes.

Homebrew your PC sound card to radio interface with this circuit obtained from the pages of Ernie Mills WM2U.

Practival project that contains two isolation transformers, one for AF from the tranciever to the line in on a soundcard, and one from the audio out of the soundcard back to the mic / data input of the radio. Both of which are variable inside the interface via two preset resistors.

Interfacing the IC706MKIIG for Soundcard & TNC modes

An improved version of the audio interface commonly used to connect a computer soundcard to a transceiver\'s receive and transmit audio circuits

The sudden explosion of new digital modes has taken the Amateur Radio world by storm. New modes such as PSK31 FT8 JT65 FSK441, ISCAT as well as established modes such as RTTY, SSTV, Hellschreiber and others have rocketed in popularity. In order to use these modes all that is required is a simple computer-to-radio interface which couples the computer soundcard to the radio

Simple soundcard interface that can satisfy several requirements like totally isolated AF interface, Totally isolated PTT and CW Key interface, Extend Accessory connector to interface to allow easy connection of TNC and provide a solid PTT or SEND connection

A SSTV interfsace (soundcard) to minimize RF feed back and a soundcard limiter to prevent over driving the soundcard

MLog 0.8d is a freeware logging software designed for Windows operating systems (NT, 98, ME, 2000, XP) that facilitates the logging, management, and analysis of amateur radio QSOs. It features a customizable input mask for rapid contest logging, a robust search function for existing contacts, and immediate data storage in CSV format to prevent data loss. The software also includes a double-check mechanism against reference logs during callsign entry, integrated DXCC information, and a "magic field" for streamlined data input, all within a single-window interface. Key functionalities include graphical QSL card management via _QSL-Collection_, CW output through soundcard or PC speaker, and direct access to _Radio Amateur Callbook_ data. MLog supports transceiver control via _Ham Radio Deluxe_ URLs, offers a detailed world map with locator conversions, and can launch _VOACAP_ through _HamCap_. It provides extensive data analysis options for QSLs, _Locator_ large fields, _DOKs_, _DXCCs_, QSO counts, and user-defined contest evaluations, alongside flexible import/export capabilities for various log formats.

This resource details an Arduino-based solution for instant switching between a paddle and a straight key on an Icom IC-7300 transceiver. The project addresses the IC-7300's limitation of requiring eight menu presses to change keyer type, a feature found on more expensive Icom rigs and comparable transceivers like the Kenwood TS-590SG. It also allows setting two power levels without interacting with the rig's controls. The system utilizes the IC-7300's CI-V bus (Computer Interface 5) via the classic 3.5mm connector, leaving the USB connection free for CAT control and the built-in soundcard. The CI-V bus is a single-wire TTL level bus. The project is suitable for CW operators who frequently switch between different keying methods and seek to streamline their workflow. The author rebuilt and expanded the project in 2023 to use all 8 buttons of a Nintendo controller.