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Audio Spectrum Analyser Spectrum Lab or Speclab started as a simple FFT program running under DOS a long time ago, but it is now a specialized audio analyzer, filter, frequency converter, hum filter, data logger and more. Can be used for MTHELL QRSS, DFCW, PSK, MSK, Castle. Spectrum Lab is a free audio analysis tool, lets you see the hidden world of sound. It analyzes live audio or recordings, showing you the exact frequencies present. Watch sounds change over time with a waterfall display. Need to clean up your audio? It can filter out noise in real-time. Even play with radio signals by decoding and creating special modes! While ideal for amateur radio enthusiasts, anyone can explore the science of sound for free.

Vox Recorder is a specialized Windows utility designed for amateur radio operators, and radio listeners particularly those who use radio scanners. This software allows users to record audio from various sources, but it only activates when an audio signal is detected. This feature is particularly useful for avoiding the capture of silence or background noise, which can be common in radio scanning. By focusing on the audio signals, users can create cleaner recordings that are more relevant to their interests. The utility is user-friendly and tailored for hobbyists who want to document their radio listening experiences without the hassle of editing out silence later. Vox Recorder is an excellent tool for anyone involved in amateur radio, as it streamlines the recording process and enhances the overall experience of monitoring radio frequencies. Whether for personal use or for sharing with fellow enthusiasts, Vox Recorder helps ensure that every important transmission is captured effectively.

The JACK Audio Connection Kit provides a robust, cross-platform solution for routing audio and MIDI data between various software applications with minimal latency. It addresses the common challenge of directing the output of one program, such as a digital mode decoder or SDR application, into the input of another, like a logging program or audio recorder. Jack audio is a multi platform application, runs on Linux, Windows and MacOS. This virtual audio cable functionality allows for complex signal flows, enabling users to simultaneously send audio from a single source to multiple destinations and even loop it back for recording or further processing within the same or different applications. For amateur radio operators, JACK facilitates advanced configurations for digital modes, contesting, and signal analysis. It supports intricate setups where a single radio's audio output can feed multiple decoders, spectrum analyzers, or recording utilities concurrently. The API is designed for real-time performance, crucial for applications requiring precise timing and minimal delay in audio processing.

Cybercorder 2000 was a versatile audio recording software that allowed users to capture audio from various sources, including radios and internet streams. It functioned similarly to a VCR, enabling users to schedule recordings and save them in WAV or MP3 formats on their PC. Although the software is no longer sold or supported, it provided a range of features that made audio recording easy and efficient. Users could listen to audio being captured in real-time and utilize a built-in sound editor for editing recordings. As Cybercorder 2000 has been retired, users are encouraged to consider Total Recorder Professional Edition as a suitable replacement. Total Recorder offers enhanced features such as scheduled recordings, background recording, and the ability to convert and edit sound files. With its user-friendly interface and robust functionality, Total Recorder remains a popular choice for those looking to record audio from various sources, making it a valuable tool for amateur radio enthusiasts and audio recording professionals alike.

Loop Recorder, a Windows-based software, offers continuous audio recording capabilities, specifically designed for capturing broadcasts from radio or internet radio sources. It features a **looping buffer** that prevents missing the beginning of desired audio segments, such as songs or specific transmissions. The application supports various audio formats including **MP3**, WMA, Ogg Vorbis, and WAV, allowing users to save recordings in their preferred codec. The software provides functionalities for scheduled recordings, enabling automated capture of content at predefined times. It caters to a range of users, from radio enthusiasts monitoring air traffic and scanner amateurs archiving communications, to professional environments requiring 24/7 broadcast storage or call center monitoring. The Pro version extends these capabilities for more demanding, continuous operational tasks. Compatibility spans multiple Windows operating systems, from Windows 9x up to Windows 10, ensuring broad usability across different system generations.

Capturing intermittent radio transmissions efficiently requires a robust audio recording solution that can intelligently manage disk space. Scanrec, a freeware Windows application, addresses this by providing a **Voice Operated Exchange (VOX)** control feature, enabling the recorder to activate only when audio signals exceed a user-defined threshold. This functionality is particularly effective for **FM communications** due to their strong squelch characteristics, minimizing recordings of static or noise. The software supports recording radio communications, air traffic control, and infrequently active channels, preserving disk space by pausing when no sound is detected. It incorporates an anti-clipping feature to ensure the beginning of audio events is not lost, a common issue with mechanical VOX systems. Output files are saved in WAV format, compatible with standard Windows Media Player. Scanrec operates on older Windows systems including Win95, Win98, NT, W2000, and XP, requiring minimal resources like a 486 PC, 4 MB RAM, and a sound card with line or microphone input. While optimized for FM, its VOX gate can be challenging to set for HF ham bands and World Band radio due to their poorer signal-to-noise ratios.

Captures any audio from the Internet, records audio from CD, microphone, line-in, converts any sound formats to WAVE and MP3. Total Recorder records streaming audio, Mic input, Line-in input as well as CDs and DVDs, allows users to schedule any number of future recordings

AudioCapture recorder software for Windows, Runs in the background, and starts recording when sound is detected from the microphone input.

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.

AutoRec is windows freeware time based automatic recorder - player for radio broadcast. Auto Recorder will record or play wav audio files, and execute batch or other executable application programs at scheduled times. The primary use for Auto Recorder is automatic, unattended recording and playback of network or other satellite-delivered radio station program material.

BroadWave Streaming Audio Software facilitates the broadcast of live and pre-recorded audio content over the internet, operating as a server on Windows PCs. It supports streaming from over 40 audio formats, automatically converting files for optimal delivery. The software allows for up to 8 separate live audio streams from a single PC and can serve up to 500 simultaneous listeners, contingent on available internet bandwidth. Listeners access streams directly through standard web browsers, eliminating the need for specialized client software. The free version, available for non-commercial applications, includes most features and does not expire. It supports recording live audio streams to WAV files and displaying the number of connected users. The professional version offers additional capabilities such as custom banner displays and integration with Zulu DJ Software for live mix streaming. System requirements specify Windows 7/8/8.1/10/11, with older versions compatible with earlier Windows OS releases. The application is designed for internet radio broadcasting, podcasting, and sharing live events, providing a direct method for **audio distribution** to a global audience without complex setup.

Lots of sounds recordings

NU9N recomendations for processed SSB, ESSB, AM Hi-Fi, Mid-Fi, Amateur Radio Audio Setup for transmiters, receivers and Amateur Radio Recording/Playback

Vox Recorder is a Windows utility wich allows recording sound from an audio source only when an audio signal is present; its main purpose is to avoid the recording of the silence eventually present at the input.

Windows freeware database containing frequencies, locations, and a small logging program capable or recording audio

Recorded scanner radio traffic from police and fire department communications. Stockton Police scanner recordings of pursuits, fights, shootings, officer involved shootings, in progress high intensity calls.

Xcorder is a windows Freeware audio recorder written by MM0BFF, designed to work mainly with radio receivers but may be used also in several different ways for audio recording needs.

About numbers stations, and their criptic transmissions, where to listen to them and some audio recording samples by fascinating shortwaves

EME operation news, typical moonbounce audio recordings

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!

The page provides a utility to record QSOs for amateur radio operators, allowing them to send the recorded signal back to the other station. It addresses challenges with VOX capability in radios and offers solutions for different radio models.

Shortwave Monitoring Station in Berlin: DX news, HF propagation, greyline, DRM news, QSL gallery, audio recordings and more

For amateur radio operators engaged in **radio direction finding** (RDF) and **transmitter hunting** (T-hunting) activities, this resource provides a catalog of printed circuit boards (PCBs) for constructing various DF and foxhunt-related projects. The offerings include PCBs for 80-meter fox transmitters and receivers, UHF fox transmitters with audio recording capabilities, and several designs for general-purpose radio direction finders. Specific projects like the "Simple 80M ATX-80 Transmitter" and the "N0GSG DSP Radio Direction Finder" are listed, along with attenuator boxes and specialized components for Doppler DF systems. The catalog details PCBs for projects published in prominent amateur radio magazines such as *73's*, *CQ*, *QST*, and *PE*, indicating their origin and design pedigree. For instance, the "Montreal Fox Controller" is sourced from the *Homing-In* column by Joe Moell, K0OV. The resource also lists components for advanced Doppler DF systems, including main boards, LED display boards, and antenna switch boards, with options for programmed PIC microcontrollers. Pricing for each PCB is provided, allowing hams to acquire the necessary components for their DIY RDF endeavors.

This project hereby presented is a complete HAM radio simplex 'smart' repeater, built around a Motorola GM-350/950, Arduino NANO board and a WINBOND audio recording integrated circuit

Over 100 amateur radio beacon audio files are presented, offering a direct auditory experience of propagation conditions across a wide spectrum of frequencies, from 1.8 MHz to 47 GHz. These recordings, primarily captured by IW3FZQ and IK3NWX, document signals from beacons such as DK0WCY, IY4M, GB3RAL, and S55ZRS, providing a valuable resource for **propagation study** and **beacon monitoring**. Each entry in the list specifies the beacon's callsign, its operating frequency in kHz, and the recording operator. This compilation includes signals from beacons located in various grid squares like JN55VF, JO44VQ, and IO91IN, illustrating diverse geographical origins. The frequencies covered span the 160m, 80m, 40m, 30m, 20m, 17m, 15m, 12m, 10m, 6m, 4m, 2m, 70cm, 23cm, 6cm, 3cm, 1.2cm, and 6mm amateur bands. Users can listen to these recordings to identify characteristic beacon tones and observe signal strength variations. The resource also invites other radio amateurs to contribute their own beacon audio files, fostering a collaborative archive of propagation data. The last update to this collection was on March 24, 2009, indicating a historical snapshot of beacon activity. Accessing the files requires the Real Player software.

VK3OT audio recorder qsos.

The Roma2 WebSDR provides remote access to a software-defined radio receiver situated in Rome, Italy, enabling users to listen to various amateur radio bands. It features a user-friendly web interface with controls for audio gain, DSP filtering, and bandwidth selection, including options like **2.4 kHz**, **3.0 kHz**, **4.0 kHz**, and **6.0 kHz** filters. The system supports both desktop and mobile device access, with a dedicated mobile version available for optimized performance. Operating as part of the _ROMA SDR Network_, it logs user activity, automatically recording time, frequency, and DXCC information for each session. The platform also addresses common browser-specific audio issues, such as white noise in _Chrome_, by suggesting workarounds like muting/unmuting or using alternative browsers like Firefox.

This resource provides a unique historical audio archive of 50 MHz DX contacts, documenting significant F2 and Es propagation events experienced by PA2S (formerly PA2HJS) since 1978. The collection includes recordings of beacons and two-way QSOs with stations across North America, South America, Asia, Australia, Europe, and Africa. Specific entries detail contacts with rare DX entities such as ZS6PW, VE1AVX, C5AEH, J52US, TR8CA, LU8MBL, VK8ZLX, and various Japanese stations, often noting the mode (SSB or CW) and propagation type. The archive also highlights challenging pile-up situations and frustrating near-misses during major openings. The recordings, initially in RealAudio format for solar cycles 21 and 22 and later in MP3 for cycle 23, offer a practical illustration of 6-meter band conditions over several solar cycles. The content allows hams to listen to actual signals from different continents, observing signal characteristics like typical TEP fading from 5H3RA or strong F2 backscatter from OZ1BVW. It provides a comparative perspective on propagation effectiveness between solar cycles, noting that cycle 23, while not as robust as previous cycles, still yielded interesting openings. The archive serves as a valuable educational tool for understanding real-world 50 MHz DXing and propagation phenomena.

Details the construction of an **HF converter** designed by M1GEO, George Smart, specifically to extend the frequency range of the FunCube Dongle Pro (FCD) for amateur radio reception. The FCD natively covers 64 to 1,700 MHz, but this project enables reception from 0 Hz to 64 MHz by up-converting signals to the FCD's operational range. It employs a **double-balanced mixer** with a 100 MHz local oscillator (LO) to translate incoming HF signals; for instance, a 1 MHz signal appears at 101 MHz within the FCD's passband. The design incorporates a 7th-order Chebyshev low-pass filter with a 62 MHz cutoff frequency at the input to mitigate image frequencies, ensuring cleaner spectral presentation. George provides the schematic, PCB masks, and Gerber files for replication, noting that Far Circuits also offers PCBs. The resource includes test results for the low-pass filter and measurements of LO leakage, identifying -36.8 dBm at 100 MHz as a potential sensitivity concern. M1GEO discusses potential improvements, such as adjusting the mixer's LO drive, adding a balance pot, or incorporating a post-mixer high-pass filter to reduce LO breakthrough. Audio recordings from 40m and 17m demonstrate the converter's performance with WRplus SDR software.

Windows PC control program for the Icom IC-7300 transceiver. Power-on and Power-off by software BktNetInterface for JTDX and WSJT-X, audio recording, memory management, cw keyer management, Interface for other software

A very informative review of the Icom IC-7300 direct RF sampling transceiver, including audio samples, recordings and a comparison vs the Elecraft KX3

The Shortwave Radio Audio Archive is a collection of shortwave radio recordings in both the form of a podcast and blog with embedded audio. The collection grows every day and includes both historic and modern day shortwave radio audio recordings

An overview of digital HF radio operating modes includes a sample audio recording of each digital mode by WB8NUT

Contest audio recording for N1MM. external "plug-in" which adds a QSO audio recording function.

The _Icom IC-7300_ transceiver, a popular SDR rig, can be readily configured for digital modes like FT8 using _WSJT-X_ software. This guide details the necessary steps, from downloading the correct version of WSJT-X to configuring the radio's USB audio and CAT control settings. It emphasizes a straightforward approach, aiming to simplify the often complex initial setup for new digital mode operators. K0PIR shares his practical experience, outlining the specific menu settings on the IC-7300, such as USB SEND/DPT and USB MOD LEVEL, which are crucial for proper signal modulation and transmission. The resource also covers the integration of WSJT-X's built-in logging capabilities, streamlining the process of recording digital contacts without needing external logging software immediately. This setup allows for efficient operation on various HF bands. Two embedded videos further illustrate the configuration process, providing visual aids for each step, from initial software installation to making the first FT8 contact. The author's method focuses on minimizing common setup hurdles.

An article by CT1BOH about recording amateur radio contests. Recording contests is a great tool to detect problems and improve operating efficiency

QSO Recorder Indexing service. This site allows radio amateurs to share their contest and DXpedition audio recordings, usually made with the N1MM Logger+ and the Qsorder plugin

A collection of audio recordings of some DX Peditions used as case studies to evaluate dxspedition operatios behaviour and calling stations. These audio files are excerpts from real pileups recorded directly off the air in MP3 format

The *SPACE* Amateur Radio over Internet Protocol (RoIP) system offers public audio transmissions from NASA Mission Control and astronauts, primarily for educational purposes. This service streams NASA public media sources, including *Artemis II* and the ISS public audio channel 2 feed, which predominantly features English communications. Astronaut activities on the ISS typically occur between 0700 UTC and 19:00 UTC, with transmissions most common during early mornings USA time, alongside special events such as launches or spacewalks. Users can connect to the live stream via EchoLink to the *SPACE* conference, via IRLP to the 0100 experimental reflector, or via Allstar to node 516221. EchoLink connections utilize the GSM CODEC, while IRLP and other connections default to uncompressed or u-law CODEC. The service notes that long periods of silence are common, and NASA audio sources can be periodically unavailable or noisy. Daily recordings of these transmissions are published at space.rfnet.link/recordings/, available as .ogg audio files for direct playback or .m3u8 playlist files for network streaming in applications like VLC. Each playlist file provides a list of timestamped audio transmissions, allowing users to review specific segments of interest.

From the sortwave radio audio archive, a collection of recordings of several spy numbers stations, russian, spanish, cuban audio recordings

SWLTools, an iOS application for iPhone and iPad running iOS 17+, provides real-time decoding of various digital modes. It automatically locks onto CW tones, measures sending speed, and collects callsigns, distinguishing valid entries from misreads for a reliable log. For RTTY and SITOR-B, the app allows users to set shift and speed, then automatically tunes to the two tones for text reception, supporting marine bulletins, press agencies, and NAVTEX. The application also decodes WEFAX, building charts line by line for direct saving to the photo library, and processes ACARS aircraft messages, including CRC checks for data integrity and mapping of position reports. Beyond decoding, SWLTools integrates a GPU-accelerated FFT spectrum analyzer, a scrolling waterfall display with frequency cursors, and an adjustable FIR bandpass filter to isolate signals. It supports IQ signal analysis from receivers via two-channel audio interfaces, correcting mirror images. Flexible audio input options include the built-in microphone, USB audio dongles, and Bluetooth sources, with diagnostics for audio routing and buffer status. The app records audio, plays it back, and converts recordings into shareable videos, while decoded texts and charts are also savable and shareable, with all timestamps in UTC.

Learn about the HAMTV Digital Amateur Television (DATV) transmitter on the International Space Station (ISS), transmitting video and audio in MPEG-2 format using the DVB-S protocol. Discover its history, installations, failures, and repairs, as well as the current status and live video feed. Explore the technical details and challenges of the HAMTV transmitter, including power output, polarization, and antenna location. Find recordings of previous transmissions and understand the potential signal reflections caused by various ISS components. Stay updated on the latest developments and activities related to HAMTV from the ISS.

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.

Home page of CE3SAD with information on his activity and progress expecially on the six meters band with audio recordings of some 50 MHz QSOs.

QTC-CrossCheck 1.5.0 is a free offline Windows tool for reviewing WAEDC CW QTC traffic. It analyzes QTC groups from local WAV recordings and supports comparison with UCXLog QTC data. Integrated audio playback helps verify individual QTC rows and resolve discrepancies. The portable application requires no installation or internet connection. Download the Windows ZIP archive and extract it fully before running QTC-CrossCheck.exe. A SHA-256 checksum is provided for download verification.