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Superfast analyzer for audio and radio signals. Examining radio signals is the original idea of Analyzer2000. Simply connect the AF-output of your receiver to the input of your soundcard and see, what you hear. Use SSB and you will have a feeling like using an expensive IF panorama adapter. Support for this version has been discontinued.

Galaxy DX 47HP and DX 99V2 models are highlighted, showcasing the manufacturer's current offerings in both amateur and Citizens Band radio transceivers. The site details several amateur models, including the DX 29HP, DX 44HP, DX 55HP, DX 98VHP, DX 33HP2, and DX 94HP, catering to different operational needs and power levels. For CB operators, a range of models like the DX 2547, DX 979, and DX 929 are presented, with specific features such as _StarLite_ front panel lighting for low-light conditions, as seen on the DX 929 and DX 979. The DX 979 is noted for its compact form factor and SSB capability, making it suitable for installations where space is a constraint. Conversely, larger models like the DX 939, DX 949, and DX 959 are available for those with more room, offering features such as blue lighting and integrated frequency counters. The DX 939, for instance, combines aesthetic appeal with functional design, providing clear readouts and robust audio performance. A downloadable CB radio shopping guide is also offered, enabling users to compare Galaxy's product specifications against other radios on the market, facilitating informed purchasing decisions.

Over 30 distinct shortwave (SW) receiver models are reviewed, offering insights into their performance, features, and user experiences. These evaluations, contributed by readers of the Usenet newsgroup **Rec.radio.shortwave**, cover a wide array of portable and tabletop radios, including popular units like the Grundig YB-400, Sony ICF-SW77, and various Realistic DX series models. Each review details aspects such as frequency range, tuning steps, SSB functionality, antenna performance, and construction quality, often comparing them to other receivers or ham transceivers like the Icom 725. For instance, the Grundig YB-400 review highlights its 144-30000 kHz AM/SSB coverage, direct keypad entry, and 40 station memories, noting its useful narrow bandwidth and tone switch for adjacent signal separation. It also discusses the **SSB mode** stability and the limitations of its 1 kHz frequency resolution for precise zero-beating. The review further details antenna performance, including the effectiveness of the built-in whip, the provided 7m reel antenna, and the potential for overload with larger outdoor antennas. Other reviews delve into specific issues, such as the Sony ICF-SW77's frequency display inaccuracies and timer malfunctions, or the Realistic DX-342's compact size and surprisingly good MW DXing capabilities despite its analog tuning. The collection provides practical, user-generated feedback on sensitivity, selectivity, audio quality, and ergonomic features, helping shortwave listeners understand the real-world performance and quirks of these receivers.

SIMPLEX is a free windows program which transforms any transceiver into an audio repeater. It works on HF, VHF, UHF etc with SSB, CW, FM, packet, SSTV and every modulation mode.

Voice Shaper is a freeware windows speech pre-processor for SSB transceivers. It receives the voice signal from the microphone connected to the soundcard, and sends the processed audio back to the soundcard in real time by Alex Shovkoplyas, VE3NEA

Presents Telstar Electronics as a manufacturer specializing in amateur radio accessories, detailing its history since 1995 and highlighting key product offerings. The resource specifically mentions the _VoiceMax Transceiver Speech Processor_, designed to enhance audio fidelity and punch for SSB transmissions, and the _SkyWaveDX350_, indicating a focus on signal processing and reception improvement for DX operations. The company's product categories span ham radio accessories, microphones, and RF amplifiers, catering to various aspects of a station setup. The site implies a direct-to-consumer model for these specialized components, providing technical solutions for Icom, Yaesu, and Kenwood transceivers, and supporting homebrew enthusiasts with components and technical references.

Using Hi-Fi Audio with FT-1000. Includes many FT-1000D modifications too by K6JRF

Two live MP3 audio streams provide real-time reception of meteor forward scatter signals, allowing listeners to hear radar echoes from meteoroid disintegration. The system operates on **67.25 MHz**, utilizing an Icom PCR-1000 receiver with a 6-element Yagi antenna pointed skyward. This setup detects reflections from ionized meteor trails created at altitudes of 80 to 130 km, using distant Channel 4 TV transmitters in the southeastern USA as signal sources. Scientists Rob Suggs, Bill Cooke, and Jeff Anderson of the Marshall Space Flight Center Engineering Directorate developed this experimental radar to monitor near-Earth meteoroid activity. A typical day yields about one meteor ping per minute, with significantly higher rates during meteor showers. The optimal listening period is generally around dawn, from 0800 to 1400 UT, due to Earth's orbital motion encountering more space dust on the dawn side. The system's **CW demodulator** processes the 67.250 MHz signal, presenting it at approximately 700 Hz with a 3 kHz bandwidth and AGC off, inverting the passband for Doppler shift analysis.

When one operates at low power on SSB, speech processing becomes almost essential to get through the QRM. The circuit is a low cost speech processor that will perform well with a minimum of construction effort.

HotPaw MorseDecoder, an iOS application, provides real-time translation of Morse Code audio signals into plain text, leveraging the device's microphone or headset input. It incorporates a DSP narrow-band audio filter, adjustable from 300 to 2400 Hz, to mitigate background noise and QRM, enhancing signal clarity for decoding. The application offers both an automatic decoding mode and manual controls for fine-tuning parameters such as audio filter frequency, WPM dot/dash speed, noise threshold, and Farnsworth timing. The WPM detection automatically adapts from 8 to 40 WPM, with a QRQ High Speed mode extending this range to 30-80 WPM for faster code. A built-in spectrogram aids in identifying the precise audio frequency of the CW tones. User feedback indicates effective performance with various transceivers like the Yaesu FT-857 and Icom IC-R8600, particularly when manual settings are optimized. The app's ability to visually tune stations within the passband and decode speeds beyond an operator's manual capability has proven beneficial during contests and general QRP operation.

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

CwType v2.35 provides a dedicated terminal interface for **CW operators**, facilitating Morse code transmission from a Windows PC. Users can input characters via the keyboard or a connected paddle, supporting iambic keying. The software manages transceiver control, including PTT and CW keying, through COM or LPT ports. It offers adjustable speed, dash/dot ratio, and inter-letter spacing, with real-time speed display in LPM and WPM calculated by the "PARIS" method. The program includes features like MOX mode for automatic TX on/off, configurable weighting to compensate for transceiver element clipping, and programmable F-key macros for sending predefined text or special sequences. CwType can integrate with logging software such as AALog (V1.0.3 and later) for data transfer, and supports various character sets including English, Russian, and Swedish. A beacon mode is also available, executing the Alt-F12 macro periodically at a user-defined interval. Audio output for monitoring can be routed through the internal PC speaker or a sound card, with options for sine waveform and smooth envelope generation for SSB transmitters. The software is compatible with **Windows XP/Vista/7/8/10** and is distributed as freeware.

This circuit consists of microphone amplifier and a high pass filter. Suitable to improve signal readability.

Audio setting and improvements for Yaesu FT-2000 by k6jrf

Yaesu FT857D No TX Audio, video on reparing and yaesu Mic modification, with audio improvements for SSB and FM

VE2ZAZ and distorted audio in SSB on some models prior 2006

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.

Demonstrates the _SQUIRL Field Day Logger_, a specialized software tool designed for efficient contact logging during the annual ARRL Field Day event. The resource details its core functionality, which includes real-time logging to easily readable text files, with filenames structured by callsign, band, and mode (e.g., K8DAA-20M-SSB.txt). It highlights features such as a real-time history grid of previous contacts, a dynamic USA and Canada map displaying contact locations, and a duplicate checker that provides audio notifications and pre-fills class/section data for previously worked stations. The software also includes an ADIF export function, enabling users to transfer logs to other general-purpose logging programs. The software's design emphasizes simplicity and ease of use, allowing for rapid on-the-spot training, as noted by users like W4CMB. It supports various operating systems, including Windows 98 through 8, and has been successfully run on Linux via _Wine_. Key usability enhancements include a "double-size" feature for improved readability and a "Space Mode" for quick field navigation. The version history indicates continuous development from 2001 to 2013, with significant additions like the real-time Field Day Map in 2003 and ADIF export in 2004, which allows for seamless integration with other logging platforms.

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.

For over 20 years, bhi Ltd has specialized in digital signal processing (DSP) technology to mitigate noise and interference across various radio channels. Their product line, including the _ParaPro EQ20 Audio DSP_ units, focuses on enhancing receive audio quality, even for operators without significant noise issues, by offering precise parametric equalization to suit individual hearing preferences. The core offerings are noise-cancelling speakers and in-line modules, specifically engineered for amateur radio applications, but also adapted for commercial, PMR, and marine radio systems. The company provides audio demonstrations, such as a 20m SSB example and a 14MHz band filter comparison, allowing users to hear the effectiveness of their DSP units against common QRM sources like plasma TV interference or diesel engine noise. Located in Burgess Hill, West Sussex, UK, bhi Ltd emphasizes clear voice communications, aiming to remove unwanted noise and leave only intelligible speech.

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.

A simple free running oscillator oscillating at the receiver\'s IF (intermediate frequency) beats with the incoming signals in either CW or SSB and the resultant audio frequency goes to the AF amplifier.

The page provides circuit improvements for the Kenwood TS-440S transceiver, addressing issues such as distortion in SSB signals, limited transmit frequency coverage, lack of crispness in RX audio, and flat audio response. The fixes include adjusting bias, cutting specific components, and changing capacitors to improve performance.

About SSB Audio by N4KC

Fixing notice subtle distortion on SSB receive audio on the Yaesu FT-1000D

Kenwood TS-950SDX ESSB audio mods by voodoo labs

Nexus is a free and open-source ham radio software application, built in Rust by KD9TAW, designed to integrate multiple station functions into a single program. It supports fifteen operating modes, including FT8, FT4, CW, SSB, FM, RTTY, SSTV, and APRS, with both transmit and receive capabilities across Windows, Linux, and Raspberry Pi platforms. The software provides band activity displays with country, distance, and bearing information, a call roster, a 3-D propagation globe with live spots, and alerts for new DXCC, WAS, WAZ, VUCC, and IOTA entities. It also features a native RF panadapter for Icom CI-V and Flex radios, or a live audio scope for other transceivers. Nexus integrates a comprehensive logbook, computes awards offline without requiring an account, and includes repeater search functionality with curated memory packs. It offers CHIRP CSV round-trip compatibility for approximately 1,000 radio models and is compatible with WSJT-X, JTDX, and MSHV via UDP protocol for seamless integration with existing workflows. The application supports ADIF import/export for log data management and provides accessibility features for operators with hearing or visual impairments, including screen reader compatibility and keyboard-navigable interfaces.

This article describes the construction of a high performance transmitter and receiver for SSB (voice) communication covering the 14MHz (20 meters) high frequency amateur radio band with output range 15 to 20 watts and a top audio sound quality both on transmit and receive.

The SDRcom platform provides a unique browser-native Software Defined Radio experience, emulating a traditional radio with a physical VFO dial, switches, and an analog meter. It integrates a high-resolution 64k FFT waterfall display, supporting essential modes like AM, FM, SSB, and CW. The **SDRcom Blue** version interfaces with SDRplay® receivers via a local WebSocket, while the free **Red Lite** version supports RTL-SDR V3/V4 dongles through WebUSB, including basic audio EQ and 100 memory slots, along with FT8 decoding. For advanced operators, the Red Pro version expands capabilities with 1000 memory slots, upgraded high-resolution waterfalls, and enhanced W4PAH FT8, FT4, and WSPR decoder engines. It also incorporates 4-band DSP noise reduction and an intelligent band scanner, proving beneficial for weak-signal work. The Network edition extends functionality to access hundreds of global remote SDRs, and an ADS-B aircraft decoding feature with 3D positioning and mapping is also available. All SDRcom applications are designed to run directly in a web browser, eliminating the need for any software installation. This approach simplifies access and setup for radio enthusiasts, from casual SWLs to dedicated digital mode operators, allowing immediate engagement with the airwaves.

A web site dedicated to the voodoo audio crew, a group of ESSB enthusiasts

Extended Single SideBand is any SSB transmission that exceeds the audio bandwidth of common 2.9kHz SSB J3E modes by essb.us

Technical Comments about Transmitter Intermodulation, Distortion, and ESSB (or Hi Fi Wide Fi SSB) audio or over equalization by W8JI

This transmitter covers the 160, 80, 40 and 20 metre bands and provides both SSB and properly generated CW. The CW side of this transmitter is not compromised and produces excellent CW. On SSB the audio has been tailored to provide a rising response to 3 KHz, with a sharp drop above that frequency. There is RF speech clipping to both provide more "punch" and to limit the peak output.

This article details the design and construction of a compact 20-meter QRP SSB transceiver by Pete Juliano, N6QW, measuring just 2 x 4 x 2 inches—small enough for a shirt pocket. Inspired by a 1963 QST design and refined from a prior version, it employs bilateral circuits, a 4.9152 MHz homebrew crystal filter, switched-crystal VXO for 60 kHz coverage (14.160-14.220 MHz), and standard components like ADE-1L mixers and IRF510 PA for 1W output. Key innovations include a double-sided PCB skeletal frame for shielding and isolation, Vectorboard sub-assemblies, and ultra-miniature relays. The bilateral receiver/transmitter shares stages, omitting AGC for simplicity, while a W3NQN LPF and optional 10W external amp enable DX contacts. Tune-up focuses on crystal matching and bias for linearity. Videos on YouTube demonstrate performance, confirming excellent stability and audio. Total cost nears $100, prioritizing portability over features like CW.

Presents the digital edition of "The Communicator," a journal from Surrey Amateur Radio Communications (SARC), offering a curated collection of articles, technical deep dives, and operational reports. Each issue, such as the July-August 2026 edition, details specific **homebrew projects** like an NTP Dual Clock, a True RMS to DC Converter, and an Arduino NANO automation mod for the Yaesu FH-2. It also covers historical accounts, including the legacy of SSB pioneer Nicolaas Kooman and the mystery of the Lagercrantz suitcase radio, alongside practical operating advice and contest summaries like Field Day 2026 and the RAC Canada Day contest. The journal consistently features diverse content, from exploring the capabilities of modern transceivers like the Icom IC-9700 for digital modes to discussions on antenna theory, such as building a vertical HF antenna without radials. It also addresses contemporary issues, exemplified by an article unpacking the FAA's "CW interference" directive concerning Boeing 787 transponders, clarifying that the interference is not related to amateur radio Morse code but rather unmodulated carrier signals impacting aviation frequencies around 1030 MHz and 1090 MHz. Furthermore, the publication includes lighter fare like "No-ham Recipes," club meeting minutes, and member profiles, providing a holistic view of the amateur radio community. It offers multiple access options for each issue, including full and lower-resolution PDF downloads, an online magazine reader, and an experimental AI-LLM audio podcast version, making its extensive content readily accessible to a global audience in over 165 countries.

The Weather Fax plugin for OpenCPN allows you to directly open image files or decode audio faxes into images. With easy calibration, these images can be overlaid on charts. It supports image conversion in Mercator, polar, conic, and uniform coordinates and can transform any image into a raster chart. Additionally, it includes a built-in database for HF radio fax stations via SSB and another for retrieving data from meteorological websites.

Many low-power SSB rigs and kits lack dedicated speech processor circuitry, although most modern HF rigs include it. Speech processing is crucial for low-power SSB to overcome QRM. This simple, low-cost circuit integrates a microphone element and can be housed in a defunct desk mike. It features a feedback amplifier, audio preamplifier, and adjustable speech compression control

Single Sideband (SSB) operation requires careful attention to the relationship between a radio's displayed frequency (suppressed carrier) and the actual 3 kHz wide audio signal. This resource clarifies how Upper Sideband (USB) and Lower Sideband (LSB) signals occupy spectrum above or below the indicated frequency, respectively. It provides practical examples for General Class operators on the **20m** and **40m** bands, such as setting a VFO to 14.226 MHz for USB on 20m or 7.178 MHz for LSB on 40m, to maintain a safe margin from band edges. The resource emphasizes the critical importance of staying within allocated band limits to prevent out-of-band emissions, particularly when operating close to band edges. It includes relevant excerpts from **FCC Regulation Part 97**, specifically section 97.307, which details emission standards, necessary bandwidth, and spurious emission attenuation requirements. The text explains that unused sidebands are considered spurious emissions and notes that modern HF equipment typically exceeds the 43 dB spurious emission reduction standard, often achieving 60 dB or more.

A dual insert microphone design for the Icom IC-7300 transceiver utilizes a **Besson BZ2400 M4 Rocking Armature** insert for frequencies from 500 Hz to 3 kHz, exhibiting a rising response of approximately 11 dB. A generic Electret Condenser insert, powered by the transceiver's microphone line, covers the low-frequency range from 100 Hz to 500 Hz. A Low Pass Filter is incorporated after the Electret insert to prevent frequency overlap, and a pre-set potentiometer (VR1) adjusts the low-frequency response, balancing the output of both inserts. The design emphasizes a "Close Talking" arrangement and addresses audio "colorization" by housing the Besson insert in a thick rubber holder with a foam boot, separate from the circuitry, with the Electret insert also wrapped in a foam boot. Critical importance is placed on using the correct BZ2400 M4 insert with 12 holes in its face plate. The frequency response table for the BZ2400 M4 insert shows 0 dB at 500 Hz, rising to +11 dB at 3000 Hz, while the Electret insert with the Low Pass Filter provides 0 dB at 100 Hz, rolling off to -9 dB at 500 Hz and -50 dB at 3000 Hz. This combination ensures a broad, balanced audio spectrum for SSB operation. The project includes a circuit diagram, a comprehensive parts list detailing components like a 1 Henry iron-cored inductor (L1) and various capacitors, and a board layout within the metal tube. The completed unit provides a tailored audio profile for the IC-7300, enhancing transmit audio quality.

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.

Demonstrates _FreeDV RADE_, an open-source digital voice mode for HF, which combines machine learning with classical Digital Signal Processing (DSP) to achieve improved speech quality and spectral efficiency. Released in June 2025 by ARDC grantee FreeDV, RADE operates at Signal-to-Noise Ratios (SNRs) as low as -2 dB and occupies approximately 1.5 kHz of bandwidth, half that of a typical SSB signal, while transmitting about 8 kHz of voice audio. The mode also features an optimized Peak-to-Average Power Ratio (PAPR) for efficient power amplifier use, reducing heat and consumption. Users, such as _VK3TPM_, report significantly improved listening ease compared to analog modes, particularly in high HF noise environments, making it easier to conduct nets across various Australian states. The mode's integration into popular radios like the _FlexRadio 6000_ series allows direct operation without external computers. A C library for RADE is available, facilitating broader integration into other radios and SDR programs, with development continuing on FreeDV RADE v2 to further narrow bandwidth below 1 kHz.

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.

Optimizing on-air audio for SSB, DXing, and contesting operations is addressed through a range of specialized audio processing equipment. The offerings include multi-band equalizers, specifically 5-band, 8-band, 10-band, and 12-band units, some integrated with features such as compressors, echo effects, noise gates, and phase rotation capabilities. These devices are engineered to interface with common amateur radio transceivers, with explicit compatibility noted for models like the Yaesu FT-DX10, FT-DX101D, FT-1000MP, FT-DX5000, Collins HF-380, and Flex 6300, alongside analog S/P meters for Icom rigs. The product line focuses on enhancing microphone audio characteristics, supporting XLR dynamic microphones for improved signal clarity and presence. The manufacturer, DB6QW Electronics, emphasizes direct support and a 100% manufacturer's warranty, reflecting confidence in product quality and operational reliability. This resource details specific audio processing tools designed to refine the transmitted audio signal, providing operators with granular control over their voice characteristics for competitive and casual amateur radio communications.