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The recognition of telegraphy masked by noise at 40 and 80 signs/min telegraphy speed was studied in 10 normal-hearing subjects at different sound pressure levels (25-85 dB SPL in steps of 5 dB) as well as at different test frequencies (2000, 1000, 800, 630, 500 and 250 Hz). The ability to recognize the signs varied with varying SPL. Recognition for most of the subjects was best at an SPL close to 70 dB. All subjects improved their recognition as the frequency was lowered to 500 Hz, some even at 250 Hz. These facts should be taken into consideration when training telegraphy operators as well as in the construction of radio receivers to permit listening at low frequencies. Furthermore, the critical ratio was calculated at the different test frequencies.

Single-sideband (SSB) radio enhances spectral efficiency but poses challenges with audio intelligibility, particularly in noisy conditions. A microphone audio compressor addresses these issues by dynamically managing the audio signal’s dynamic range. It amplifies quiet sounds and attenuates loud ones, ensuring consistent audio levels for improved clarity. Benefits include increased intelligibility, higher average power, and reduced spurious emissions. While essential for optimal SSB performance, careful parameter adjustment is crucial to balance natural sound quality and effective communication across various operating modes.

CWoip (CW over internet protocol) Full Duplex morse code audio with high fidelity sound. Allow to conduct morse code CW over the internet. Fast, Full Break-in Qsk, due to low latency, free software. With the ability to conduct an audio CW QSO between 2 to 100 iCW OPS

This page provides a detailed guide on how to build your own radioless Allstar node for ham radio operators. It includes information on power supply, components needed, wiring instructions, and tips to avoid common issues like ground loop hums. The author shares personal experiences and recommendations for specific components like microphones, audio amps, and sound fobs. Whether you're a beginner or experienced ham radio operator, this DIY project can help you set up a cost-effective and functional Allstar node for communication purposes.

The Greencube Terminal Program enhances communication with the Greencube/IO-117 satellite by enabling message exchange via a PC's soundcard and integrating with multiple loggers like ACLog and Cloudlog. It supports new contact identification through an ADIF file, featuring a color-coded "Dupelist" for tracking unconfirmed contacts and grids. The software is compatible with voice notifications for efficient satellite communication management.

The ICOM IC-745 is a durable 1980s HF transceiver, ideal for enthusiasts who enjoy restoration. While lacking modern serial control, it supports digital modes with modifications like sound card connections and frequency stabilization. Enhancements like an RTL-SDR panadapter can also be added, making it a versatile and valuable radio for contemporary use.

MyWaveRecorder is a lightweight utility designed to capture and save any audio played on your computer. Whether it’s sounds generated by programs like CW_PLAYER, WX_PLAYER, MyWaveRecorder itself, your microphone, your sound card, or even streaming audio from the internet, this tool records them all with a single click.

Morse News reads RSS/Atom messages and translates them into Morse code, playable as CW radio tones, spark-gap sounds, telegraph clicks, or via a physical telegraph sounder. It supports Farnsworth effects, natural American Morse timing, and realistic audio enhancements. Twitter integration allows user-generated Morse messages.

The N7YG Digital Engine, functions as a streamlined digital modem, supporting **PSK**, **RTTY**, and **MFSK** modes. It eliminates many ancillary logging and awards features found in other software, focusing instead on providing a dedicated digital interface. The software is specifically engineered to complement the N3FJP logging suite, offering a simple digital modem with a floating waterfall display that can coexist on the same screen as the logger. The application includes support for PSK Reporter, EXTFSK, TinyFSK, and K1EL Winkey FSK, enhancing its utility for various digital operations. Key features comprise a separate waterfall window, a main GUI with operational controls, receive and transmit display areas, and 10 Macro Buttons across 10 user-definable macro banks, totaling 100 macros for general and contesting use. Configuration options include sound card selection, digital gain (0-32767), AFC Level (0-100), AFC Width (in Hz), and COM Port TX keying for VOX/SignaLink or direct port control. Input and Output Mixer buttons provide direct access to OS audio mixer controls for precise level adjustments. The software is digitally signed with a security certificate, aiming to prevent conflicts with antivirus programs.

How to record the full contest audio into .mp3 file(s). t is possible to record the receiver's audio through the USB sound card in the radio (USB Audio CODEC), but only the transmitted SSB audio can be recorded, unfortunately not the CW.

Learn about Amateur Television (ATV) on the 23 cm band (1240-1300 MHz) in this article from the September and October 2000 issue of Mégahertz magazine. Discover how ATV adds a new dimension to QSOs by allowing hams to visit stations, transmit real reports on antenna installations, follow signal paths on camera, and have simultaneous sound transmission. Explore the world of ATV experimentation, comparison, and innovation, made easier by existing equipment in many ham radio operators' homes. Find out about the ATV bands, bandwidth requirements, and the 23 cm band as a starting point for ATV activities.

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.