Search results

Eight-channel Audio Spectrum Analyzer is a set of Real-Time Multi-Channel Gauges for investigation of data accepted from any ADC you will want or 16-, 24- and 32-bit ADC of sound card. WDM drivers support. FFT Spectrum Analysis, OscilloScope, Frequency counter, AC/DC voltmeter, Signal-to-Noise Ratio, Signal-to-Noise and Distortion, Spurious-Free Dynamic Range, Effective Number Of Bits, Total Harmonic Distortion, Inter-Modulation Distortion, Phase Shift. Special modes of dual-channel FFT spectral analysis: Separate channels spectra, Spectra of digital sum, difference, product of two signals, Spectrum of digital product of original signal and its fundamental, Spectrum of Real and Complex Transfer Function, Cross Spectrum. Standart weighing of spectra according IEC and CCIR. Oscilloscope modes (for dual-channel ADC) are: original signals, sum, difference, dependence of one channel on another, amplitude distribution of input signals.

PA3FWM's software defined radio (SDR) page documents his extensive hardware and software development efforts between 2004 and 2009. Initial experiments utilized a direct conversion receiver with 90-degree phase difference, feeding a PC soundcard at 48 kHz sample rate, covering 24 kHz of spectrum around a 7080.5 kHz local oscillator. This setup, similar to AC50G's QEX 2002 article, allowed for basic I/Q signal processing to distinguish signals above and below the LO frequency. Limitations included fixed crystal frequencies, 16-bit dynamic range, and narrow bandwidth. Subsequent hardware iterations aimed for enhanced performance, incorporating external 24-bit ADCs with 192 kHz sample rates, connected via 10 Mbit/s Ethernet. A **MC145170-based PLL** and programmable octave divider provided a 58 kHz to 30 MHz tuning range. The **Tayloe mixer** was employed, with differential outputs feeding a PCM1804 ADC. An ATmega32 microcontroller handled serial data conversion to Ethernet frames, though without CRC calculation due to processing constraints. Later designs integrated AD7760 2.5 Msamples/second ADCs and a Xilinx Spartan-3 FPGA, enabling direct reception of 0-1 MHz spectrum and eventually 2.5 MHz bandwidth across the shortwave spectrum. Software was refactored to use an initial 8192 non-windowed FFT for efficient high-bandwidth processing. The project culminated in a two-way QSO on 21 MHz using the developed hardware and software, demonstrating transmit capabilities with a D/A converter. The system exhibited a 2.5 MHz wide spectrum display and a zoomed 19 kHz display, capturing signals like ionospheric chirp sounders and RTTY contest activity. Challenges included noise leakage from digital circuitry and cooling for high-power dissipation components.

QRZCQ.com provides a centralized online platform for amateur radio operators, integrating a global callsign database with DX Cluster functionality. The service features real-time DX spotting, filtering capabilities for specific bands (e.g., 160m, 80m, 40m, 20m, 15m, 10m), and specialized filters for awards like IOTA, SOTA, WWFF, and QRP activity. It also includes a logbook, QSL manager lookup, contest calendar, and various ham radio articles and news feeds, supporting a wide range of operating activities and information retrieval. The platform aggregates data from multiple sources, offering a dynamic view of on-air activity and callsign information. Users can register for free to access additional services, including a personal logbook, buddy lists, and chat features, fostering community interaction among over 198,600 registered users. The DX Cluster displays recent spots with frequency, DX call, spotter, and remarks, covering bands from VLF to VHF. Beyond DX spotting, the site provides resources such as repeater directories, propagation information, and a swapmeet, making it a multi-faceted tool for both casual browsing and serious DXing or contesting. The service also highlights active users, latest news, articles, and videos, keeping the content fresh and relevant.

The Receiver Test Data resource is a detailed review database focusing on the performance metrics of various radio receivers. The methodology involves rigorous lab measurements, often adhering to standards such as the ARRL RMDR (Reciprocal Mixing Dynamic Range) and BDR (Blocking Dynamic Range). Specific test equipment and protocols are utilized to assess parameters like noise floor (dBm), AGC threshold (uV), and LO noise (dBc/Hz). For example, the _Icom IC-7300_ is evaluated with a noise floor of **-133 dBm** and an LO noise of **-141 dBc/Hz**, providing insights into its performance under different operational conditions. The resource includes a wide range of models, from the _Elecraft K3S_ to the _Yaesu FTdx-101D_, each tested for dynamic range, sensitivity, and selectivity. The data is sorted by key metrics such as third-order dynamic range and phase noise limitations, with RMDR values calculated by subtracting 27 dB from LO noise figures. This structured approach allows users to compare different receivers' capabilities, focusing on technical specifications and performance outcomes in various scenarios. DXZone Focus: Review Database | Lab Measurements | -133 dBm | ARRL RMDR

Microhams is a dynamic organization of hams in the Puget Sound area. The club includes a broad range of people from our local tech industry who participate in just about every aspect of our hobby.

Comparison of FT-1000D FT-736R FT-817 FT-847 FT-897 IC-765 Orion TS-2000 Spectral purity of a continous carrier, of a SSB and CW signals

Optimizing weak signal reception on the HF bands, particularly in the presence of strong local QRM, often necessitates specialized receiving antenna systems. This resource details the _HI-Z Antennas_ product line, focusing on phased vertical arrays designed for superior noise rejection and directivity. It covers components such as the 4-Square and 8-Element array controllers, which allow for rapid switching of receive patterns, and dedicated low-noise preamplifiers to improve system sensitivity. The site also presents various bandpass filters, crucial for mitigating out-of-band interference and enhancing the dynamic range of the receiver. The HI-Z systems are engineered to provide significant front-to-back and side rejection, often yielding **20-30 dB** of attenuation to unwanted signals, which is critical for DXing and contesting. Users can achieve a notable reduction in local noise, allowing for the discernment of signals that would otherwise be buried. The array controllers facilitate quick pattern changes, enabling operators to null out interference or peak weak signals from distant stations, effectively extending the reach of their receive capabilities by improving the signal-to-noise ratio.

Aggregating real-time contest scores, this online scoreboard serves as a central hub for participants and spectators to monitor live progress during amateur radio competitions. It directly interfaces with widely used contest logging programs, collecting score data as operators make contacts. The platform then processes and displays these scores on dedicated contest pages, offering an immediate overview of standings. Supporting a diverse range of **DX contests**, the system accommodates various operating modes and rulesets. It facilitates score tracking for events like the YB DX RTTY, RSGB Commonwealth (BERU), EA PSK63, and the South America 10 Meter contest, among others. This functionality allows contesters to gauge their performance against competitors instantaneously, fostering dynamic participation. The scoreboard's integration with multiple contest log software applications ensures broad compatibility, making it accessible to a significant portion of the contesting community. It provides a crucial service by centralizing score visibility, enhancing the competitive experience for **amateur radio operators** worldwide.

A 500 kHz to 5.5GHz 2-port vector network analyzer designed for use with any Linux, Windows or MacOS computer. High performance: up to 80 dB dynamic range in the MHz range; up to 40 dB in the GHz range

Receiver dynamic range is the ability of a receiver to receive a weak signal without loss of readability while a strong signal is present.

The basics of radio receiver dynamic range performance used for specifying the performance of radio receivers used in radio communications systems.

Mic online calculator , Microphone Dynamic Range Calculator, Microphone Sensitivity Calculator

An inexpensive spectrum analyzer for the radio amateur, with a respectable performance and a quite good dynamic range. Schematic and basic information on how spectrum analyzers works.

**Low SWR Podcast** was a dedicated platform for amateur radio enthusiasts, produced by Rich, **K0EB**, and his son Brady, **AC0XR**. The podcast covered a range of topics relevant to the ham radio community, including technical discussions, DXing, and radio news. Episodes were crafted to engage both seasoned operators and those new to the hobby, providing insights into the evolving landscape of amateur radio. Despite its cessation in 2014, the podcast remains a testament to the dynamic nature of ham radio, reflecting the changing interests and priorities of its creators. The podcast's archive offers a valuable snapshot of amateur radio discourse during its active years. While no new episodes have been produced since 2014, the existing content continues to serve as a resource for understanding past trends and discussions within the community. The podcast's focus on technical content and real-world applications made it a useful tool for operators seeking to enhance their knowledge and skills. Although inactive, the Low SWR Podcast's legacy persists, highlighting the enduring appeal and educational value of amateur radio media.

An explanation of the different procedures and definitions that are commonly used for blocking dynamic range (BDR) measurements. Dynamic range in general is the ratio between the weakest signal a system can handle and the strongest signal the same system can handle simultaneously without an operator switching attenuators or turning volume potentiometers

Over 15 years of continuous operation, Ham365 provides a web-based logging solution for Amateur Radio Operators, allowing them to maintain and share their QSO records online. Originally launched as the online logbook component of Ham Radio Deluxe, it has since evolved into an independent platform, now integrating with numerous other logging applications. The platform shares its database with HRDLOG.net, ensuring that operations performed on one site are reflected on the other, maintaining data consistency for users. Key features include an overview of the latest hour's activity, a display of the most recent QSOs, and a map visualizing recent contacts. It also highlights "Most Wanted" entities and ongoing DXpeditions, providing a dynamic view of current amateur radio activity. The logbook supports various operating modes, including SSB, RTTY, PSK31, and FT8, and handles ADIF data for interoperability. Users can manage their logbooks, track DX activity, and utilize features like OQRS (Online QSL Request System) through its integrated functionalities. The system is designed to be accessible to a wide range of operators, from casual ragchewers to avid DXers and contesters.

Exploring digital radio modes, the author rethinks how to adjust transmit and receive levels in WSJT-X. Despite effective communication using Yaesu's settings, a new procedure aims for better performance. For RX, set audio device levels to 100%, disable AGC, and adjust RF gain. For TX, enable "Remember power settings" and adjust power output to avoid ALC engagement. This method ensures reliable communication without signal degradation, enhancing dynamic range and minimizing noise.

The Score Distributor facilitates real-time score forwarding for amateur radio contests, automatically transmitting data from various logging software to multiple online scoreboards. By configuring logging applications to send score data to the Distributor, operators ensure their current score is simultaneously represented on platforms like the _Contest Online ScoreBoard_ (COSB) and the Live Contest Score Server by R4WW. This system eliminates the need to choose a single scoreboard, providing broader visibility for participants. This utility enhances the competitive experience by allowing contesters to monitor their performance against other stations throughout an event. Observing real-time standings can provide significant motivation, particularly during periods of challenging propagation or when striving to maintain pace with club members or peers. The platform supports almost all major contest logging software, simplifying integration for a wide range of operators. Developed by WA7BNM, the Score Distributor was last revised on June 14, 2023. It aggregates score data, offering a unified point of submission that then disseminates the information, ensuring a **single point of entry** for broad scoreboard coverage and improving the dynamic feedback loop for participants.

A homebrew spectrum analyzer, the Specan, provides a crucial measurement capability often missing from the typical amateur radio shack, allowing for detailed analysis of RF signals up to 70 MHz. This double-conversion superheterodyne receiver design incorporates 112 MHz and 12 MHz intermediate frequencies, utilizing an _Si570_ as the local oscillator for fine tuning down to 1 Hz steps. It offers two resolution bandwidths: 300 KHz for broad spectrum sweeps and 1 KHz for precise close-in distortion measurements, achieving an 80 dB spur-free dynamic range at 1 KHz resolution. The project, a reboot of the classic _W7ZOI/K7TAU_ design from November 1998 QST, integrates an _Arduino_ microcontroller for controlling the Si570, managing a front-panel LCD, and communicating with a PC for spectrum plotting. This approach significantly reduces cost compared to commercial units, making advanced RF diagnostics accessible to homebrewers. The Specan can measure carrier suppression, VFO cleanliness, antenna VSWR, transmitter harmonics, and filter passband shapes, providing insights beyond what an oscilloscope or frequency counter can offer. Construction emphasizes modularity and careful shielding, with each stage built and tested individually on unetched copper clad board. The design includes detailed instructions for integrating the Arduino, building the Si570 oscillator, and aligning the various modules, often using the Specan itself for calibration. It requires a well-regulated linear power supply and can be built with common tools and readily available components, making it a practical and rewarding endeavor for those looking to enhance their RF test bench.

Facilitate seamless communication in the world of packet radio with PoPT, a versatile terminal program designed for AX.25 protocol enthusiasts. Operating across multiple platforms, including Windows, Linux, macOS, and Raspberry Pi, it caters to a wide range of users. The program supports various connection methods such as KISS over TCP/Serial and AXIP over UDP, ensuring compatibility with Linux AX.25 devices. This flexibility allows operators to maintain robust connections in diverse environments. Developed with Python 3.11, PoPT is currently under active development, reflecting a commitment to staying at the forefront of technological advancements. Its multi-platform nature ensures that operators can leverage their existing hardware setups without the need for additional investments. The program's ability to handle different connection types makes it a valuable tool for those engaged in packet radio operations, whether for personal experimentation or more structured communication networks. PoPT's ongoing development promises future enhancements and features, making it a dynamic choice for operators looking to explore the capabilities of AX.25 packet radio. Its adaptability and support for modern systems position it as a practical solution for contemporary amateur radio enthusiasts.

Integrating a _Software Defined Radio_ (SDR) into an existing ham radio setup involves connecting it with a standard transceiver (TRX), power amplifier (PA), and antennas. The core component is a splitter box that facilitates the connection between the TRX and the SDR, allowing for simultaneous operation without modifying existing equipment. In receive mode, the splitter ties the antenna inputs of both the TRX and a direct conversion receiver (DC RX) together. During transmission, the DC RX input is grounded via a fast telecom relay controlled by the transceiver's -SEND signal, incorporating a 10ms delay for safety. The splitter box includes a 3.7 dB input attenuator for impedance matching and acts as a protective fuse for the DC RX input. Ground loops are mitigated using common mode balun transformers, while the DC RX input is insulated with a broadband transformer. An audio switch box complements the setup, enabling users to listen to either the main transceiver, the SDR output, or both simultaneously. This configuration ensures noise immunity and safety, with the splitter housed in a screened box made from PCB material. On-air tests, such as the CQ WW 160m CW DX Contest, demonstrate the system's effectiveness, showcasing the SDR's ability to handle crowded band conditions with superior selectivity and dynamic range. The SDR's narrow bandwidth filters and waterfall display provide significant advantages, allowing operators to detect weak signals amidst strong interference. The integration of SDR with conventional radios offers enhanced operational flexibility and performance in challenging environments.

Inrad Roofing Filter installation instruction, The IC-775 Roofing Filter Mod consists of a 6 pole, 5 kHz wide filter followed by a high dynamic range, feedback amplifier.

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.

Assessing the ICOM IC-R9000 communications receiver, this review details its operational parameters and user experience for radio enthusiasts. Introduced in 1985, the IC-R9000 covers a broad frequency spectrum from 0.1 MHz to 1999.8 MHz, making it suitable for a wide array of listening activities from medium wave (MW) to VHF/UHF. Key performance metrics include a dynamic range of **102 dB** with the narrow SSB filter, crucial for discerning weak signals in crowded bands, and its substantial physical dimensions of 424 x 150 x 365 mm and 20 kg weight. The receiver's architecture supports various modes, though it notably lacks synchronous detection, a feature often desired for improved AM reception under fading conditions. It incorporates 1000 memory channels and robust scanning capabilities, facilitating efficient monitoring across its extensive frequency range. This analysis provides insights into the IC-R9000's capabilities and limitations, offering a historical perspective on a significant piece of amateur radio and shortwave listening hardware.

John Lemay’s (G4ZTR) review of the Yaesu FT-847 offers a practical look at this all-mode transceiver, spanning 160m to 70cm, including 4m. While it falls short in dynamic range and sensitivity, its "shack-in-a-box" design shines for VHF DXing and multi-band use. Lemay shares hands-on tweaks, like calibrating 70cm with beacons and integrating footswitches for SSB and CW. The TX Inhibit feature simplifies sequencing with external gear. Despite minor flaws, the FT-847’s versatility and mod-friendly nature make it a solid pick for amateur radio enthusiasts craving flexibility.

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.

The NR-1, conceived and implemented by SV3ORA, functions as an **antenna noise blanker** to suppress impulse noise before it reaches the receiver. This device is explicitly not a QRM-eliminator or X-phaser, and it operates without requiring a separate antenna. Its primary goal is to improve receiver performance by reducing annoying noise. Documentation includes a comprehensive manual detailing its operation, alongside several videos demonstrating its functionality. The NR-1 is available for purchase directly from Elisys via their online shop. Numerous radio amateurs have reviewed the NR-1, with Pavel OK7PM highlighting significant improvements in receiver **dynamic range**. Further insights are available in an article published in the Greek magazine SVnea and through various reviews posted on eham.net.