Search results

CwGet v2.55 is a software application for amateur radio operators designed to decode Morse code (CW) signals into text using a standard computer sound card, eliminating the need for specialized hardware. The program features a customizable interface with a spectrum display for visualizing signal frequencies and peaks, an oscillogram for monitoring signal presence and setting detection thresholds, and a received symbols window for displaying decoded text. Key functionalities include Automatic Frequency Control (AFC) to lock onto signals, adjustable FIR and IIR filters for noise reduction, and a burst filter to mitigate short noise impulses. It also supports automatic CW speed detection, multiple character sets, and the ability to record and replay received audio. Integration with logging software like AALog is facilitated through double-click word transfer, and transceiver frequency control is possible via the Omni-Rig interface, allowing for automatic tuning of the radio's VFO or RIT. The multi-channel decoder feature can simultaneously decode up to five strong signals within a 1600 Hz bandwidth, displayed in a separate Multi-RX Window with an adjustable squelch. CwGet also offers the capability to decode signals from pre-recorded WAVE files and can function as a narrow-band sound DSP filter for aural decoding. This is a commercial version and it has been tested on latest MS Winows versions.

Shareware dual channel audio spectrum analyzer for Windows 2000/XP which can provide either a scrolling time-frequency display or a spectrum analyzer scope display in real time for any sound source connected to your sound card. Can be used for MTHELL, QRSS and DFCW by R S Horne

Miami live police scanner feed provided via youtube. Miami PD Live Radio - Police Scanner online

SysLabs RadioControl is a software platform for radio device control and application development. It operates on _Windows_ versions from Windows 95 and Windows NT 4.0 through _Windows 11_. The software is available in Lite, Standard, and Professional editions, each including Frontpanel for direct radio control, a Frequency Database for management, and a Memory File for channel operations. Features include frequency identification, memory scanning, and graphical spectrum views with bitmap export capability. The Professional Edition supports multi-device control and utilizes radio device-internal scanners, achieving scan rates of **40-60 steps per second** compared to the RadioControl-internal scanner's **10-20 steps per second**. Supported devices for internal scanning include AOR AR-5000, AR-8200, AR-8600, AR-ONE, R&S EB200, and various Icom receivers and transceivers. RadioControl supports older devices such as ICOM IC-R71, IC-R7000, IC-706, IC-735, YAESU FRG-8800, and FRG-9600, extending their control capabilities. The platform offers APIs for integration and supports import/export with formats from VisualRadio, SCANcontrol, shoc Radio Manager, WiNRADiO, AOR ACEPAC-3A, as well as generic Text, CSV, and HTML. DXZone Focus: Radio Control | Windows | Frequency Management | API

Live streaming audio of VHF marine radio channels 05A, 16, and 22A from NJ and NY City

WiNRADiO Communications, a division of Radixon Group, was established in 1996 to commercialize extensive research in radio communications. The company specializes in integrating radio and computing technologies, offering a diverse product range for government, military, security, and amateur radio enthusiasts. Their product line includes the WR-G65DDCe 'EXCALIBUR Sigma' HF/VHF SDR receiver, noted for its capabilities, and the G31DDC EXCALIBUR, recognized for its price/performance ratio in shortwave listening with improved AMS and Noise Blanker features. The company also produces the G39DDC series EXCELSIOR for serious monitoring, WR-G526e/G527e/G528e modular SDR solutions for high-performance applications like phase-coherent direction finding, and the low-cost WR-G305e/G305i VHF/UHF receivers. Professional counterparts, the WR-G315e/G315i, support APCO P25 decoders and trunking options. WiNRADiO's offerings extend to the PFSL-G3 field strength logging system for mobile signal coverage, advanced multichannel telemetry systems like the MS-8323, and specialized antennas such as the AX-31C Log-Periodic and AX-81S active HF antenna. DRM decoder software is available for G3 Series receivers, enabling clear reception of DRM broadcasts. The WSS-420 Weather Satellite Receiving System and various antenna rotators are also part of their product ecosystem. WiNRADiO supports multiple operating systems, with MacRadio for Apple Macintosh users and LiNRADiO for Linux developers, providing drivers and network receiver solutions like the RLX-810.

CHIRP is a free, open-source, cross-platform radio programming tool that supports a large number of transceivers from manufacturers such as Icom, Kenwood, Yaesu, Alinco, Wouxun, Puxing, and Baofeng. Chirp radio software run on Windows, Linux, and macOS, enabling users to exchange data between different radio models and interface with multiple data sources and formats. The program streamlines the configuration of memory channels, frequencies, and various settings for amateur radio handhelds. Specific models supported include the _Icom IC-7300_, _Kenwood TH-D74_, and _Yaesu FT-818_, among many others. CHIRP provides compatibility with various file formats, including Generic CSV, RT Systems CSV, ARRL Travel Plus (.tpe), and manufacturer-specific formats like Kenwood KPG-44D (.dat) and Icom Data Files (.icf). Additionally, it integrates with the DMR-MARC Database for enhanced programming capabilities. Users can download CHIRP for their platform and access extensive documentation, including a FAQ and a mailing list for support. The project encourages users to consult existing documentation and open/closed tickets before submitting new bug reports or feature requests.

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.

KSM Kenwood Smart Memory is a program to read and update the memory channels of a Kenwood amateur radio. The current supported types are: TS-450S, TS-570D, TS-570S, TS-690S, TS-870S, TS-940S,TS-950S.

EasyPal is a sophisticated digital Slow-Scan Television (SSTV) application that utilizes soundcard technology to encode and decode SSTV signals. Developed by the late Erik Sundstrup (VK4AES SK), this software has evolved into a versatile communication tool for amateur radio operators, extending beyond basic image transmission capabilities. EasyPal implements Digital Radio Mondiale (DRM) encoding technology, enabling efficient data transmission over narrow 2.5 KHz channels on both HF and VHF frequencies with remarkable speed. The application supports multiple file formats, including jpg, pdf, txt, doc, and xls, as well as specialized forms such as ICS-213 and ICS-213 (ARES). Additionally, EasyPal offers email functionality through designated repeater stations with internet access. Its responsive development history and robust feature set have established it as a premier digital SSTV solution in the amateur radio community, though users of Windows 11 should note specific configuration requirements to ensure optimal performance.

Constructing a compact, directional antenna for the 6-meter band presents unique challenges, especially for operators with limited space or those seeking portable solutions. This project details the build of a 50 MHz Moxon rectangle, specifically engineered for balcony or temporary mast deployment, using readily available materials from a typical hardware store. The design emphasizes ease of construction and portability, allowing for quick setup and breakdown. The antenna's dimensions are precisely calculated using _Moxgen_ software for 50.200 MHz, ensuring optimal performance. Key construction techniques include using aluminum U-channel for elements, fiberglass driveway markers for insulation, and cable ties for secure assembly. The guide provides detailed instructions for fabricating the driven element, reflector, and boom, including a clever method for creating foldable element tips for transport. Performance observations indicate a respectable front-to-back ratio, capable of reducing an S7 signal to S0 when pointed away, and a modest gain over a simple wire antenna. The design incorporates a ferrite bead choke balun at the feedpoint to mitigate common-mode current and reduce shack noise, a critical consideration for urban or apartment-based operations.

CW Skimmer 2.1 employs a high-sensitivity CW decoding algorithm based on Bayesian statistics, enabling simultaneous decoding of up to 700 CW signals within a receiver's passband on a 3-GHz P4 system when paired with a wideband receiver. The software features a fast waterfall display with sufficient resolution for visual Morse Code interpretation, automatically extracting and labeling callsigns on the waterfall traces. Extracted callsigns are exported as DX cluster spots via an integrated Telnet cluster server. The application includes a DSP processor with a noise blanker, AGC, and a variable-bandwidth CW filter, alongside an I/Q Recorder and player. It supports both 3 kHz radio passbands and wideband SDR receivers like SoftRock, RF Space SDR-IQ/SDR-14, SRL QuickSilver (QS1R), HPSDR Mercury, and Microtelecom Perseus. System requirements specify Windows XP/7/8/10 (32-bit or 64-bit), a Pentium-4 2.5 GHz for wideband operation or 1 GHz for 3-kHz radios, a COM port for CAT control, and a stereo sound card supporting 48 kHz sampling. It integrates with Elecraft KX3, Icom IC-7300/IC-7610, and Flex 6000 series radios, with documentation available for various setup configurations.

Manufacture CATS antenna rotator and digital controls. Service, stock, and provide parts for top quality AMERICAN-MADE antenna rotators from companies such as Alliance, C.A.T.S., CDE/Hy-Gain, and Channel Master, both young and old.

The article details antenna tuning procedures, emphasizing SWR measurement and adjustment for both mobile and base station setups. It explains that SWR (Standing Wave Ratio) is the ratio of transmitted power to reflected power, with high SWR indicating poor impedance match and potential damage to a transceiver's final amplifier. Specific instructions are provided for CB antennas operating between 26-27 MHz, recommending initial SWR checks on channels 1, 20, and 40 to determine if the whip needs shortening or lengthening. Adjustments should be made in small increments, approximately 1/4 inch at a time, aiming for an SWR of 1.5:1 or better. For _Ham radio_ and other antennas, the same tuning principles apply, with a strong caution regarding RF energy exposure when operating at higher power levels. The resource suggests tuning base antennas at ground or roof level before final installation to simplify adjustments. It also advises rechecking SWR after final installation to confirm no changes occurred. The _Alpha Rubicon_ resource highlights the importance of a good ground plane for mobile antennas and proper coax routing to avoid pinching or proximity to electrical wires.

DSCdecoder decodes the DSC digital signals from ships and coast stations using the sound card in your PC. You need a suitable MF, HF or VHF band radio receiver tuned to one of the DSC distress and calling channels or to one of the Navtex channels

General Mobile Radio Service Frequencies

Low cost, reliable rotor with digital display remote control.

Douglas County Sheriff dispatch channel

Catalogs over 9,300 radio transmissions heard within Finland, providing a detailed frequency database for Finnish radio enthusiasts. The resource lists frequencies for various services, including maritime VHF channel 16 at **156.800 MHz**, RHA68 channel 16 at 71.100 MHz, and _MIL AIR_ frequencies like 251.100 MHz. It also documents air traffic control frequencies, such as 123.775 MHz for Area Control and 127.000 MHz for Approach Control, alongside frequencies for Finnish Air Force operations at 140.550 MHz. The database includes entries for commercial shared channels at 170.450 MHz and 458.250 MHz, as well as specific local business frequencies like 443.125 MHz for Sale Merimasku. Shortwave broadcast entries are also present, noting stations like BBC at 6.035 MHz from Tashkent and AIR Akashvani Ext.Sce at 11.900 MHz from Bangalore. The site organizes its extensive listings by categories such as "Liikenne" (Traffic) with 2397 entries, "Radioamatoori" (Amateur Radio) with 781 entries, and "Yle" (General) with 2305 entries. The database was last updated on 26.2.2024, reflecting ongoing maintenance and additions to its comprehensive collection of Finnish radio spectrum data.

Information about railroad radio channels and frequencies is provided along with laws relating to using scanners as well as tips and suggestions for programing and using radio scanners.

Echo Link client for Linux and general purpose voice services system for ham radio use. The svxlink server consists of a core that handles the connection to the tranceiver. The core can be configured to act as a repeater controller or to operate on a simplex channel

Modifying the _ICOM IC-706MKII_ transceiver for out-of-band transmit capability involves specific surface-mount device (SMD) removal on the main circuit board. This procedure enables transmit functionality from 0.5 MHz to 200 MHz, excluding the commercial FM-Wide broadcast band, significantly expanding the radio's operational frequency range. The modification requires careful handling of small components and a fine-tipped, low-wattage soldering iron. Prior to beginning, all programmed memories and initial setup configurations must be noted, as the modification process will erase them. The instructions detail the necessary tools, preparation steps, and the precise location of the two SMD diodes to be removed. These diodes are situated near an oblong crystal can and a test point labeled _CP3_ on the main board. Successful completion returns the unit to its default configuration, necessitating manual reprogramming of memory channels and initial settings. This project is suitable for operators with experience in SMD work and fine soldering.

The MCP-F6/F7 software facilitates memory channel and menu data creation for the Kenwood TH-F6A, TH-F7A, and TH-F7E transceivers. It operates on _Windows_ XP (SP3+), Vista (SP2+), Windows 7 (RTM+), Windows 8 (RTM+), Windows 8.1 (RTM+), Windows 10, and Windows 11. System requirements include a CPU faster than the OS recommendation, RAM exceeding the OS recommendation, and **2 MB** of free hard drive space. Display resolution must be XGA (1024 x 768) or higher. Connectivity to the transceiver requires an optional PG-4Y (RS-232) or KPG-22U (USB 2.0) programming cable. The KPG-22U cable necessitates a virtual COM port driver installation. The software supports COM1 through COM20 for RS-232 communication. Installation requires administrator privileges and involves executing "setup.exe" from the extracted MFX101.zip archive. Uninstallation is performed via the Control Panel's "Uninstall a program" function or by re-executing "setup.exe." Created data files are not removed during uninstallation and require manual deletion. The software version is **1.01**. DXZone Focus: Kenwood TH-F6 F7 | Memory Management | Windows | RS-232

A full line of single-channel synthesized and crystal controlled vhf and uhf fm receivers. Great for repeaters, telemetry, and control applications.

A quick and easy method of programming memory channels The Icom IC-V8000 manual leaves much to be desired due to the translation. The operator's manual included with the Icom IC-V8000 can be very confusing to the new ham and the old timer alike, and lots of hams get very disgusted when trying to program the IC V8000 using the instructions provided with the operator's manual.

The Kenwood TH-F6A handheld transceiver can achieve an extended transmit frequency range of 137-174 MHz, 216-235 MHz, and 410-470 MHz by removing a specific diode and chip resistor from the main PCB. This modification also expands the receive range on the A-band to 142-152 MHz, 216-235 MHz, and 420-450 MHz. For the TH-F7E, the transmit range extends to 137-174 MHz and 410-470 MHz, with a corresponding receive range on the A-band. Performing these hardware changes will reset and initialize the radio's memory contents, necessitating prior backup of important channel frequencies. Instructions are provided for constructing a homemade PC programming cable compatible with the Kenwood TH-G71A, TH-F6A, and TH-F7E. The interface utilizes an RS-232-to-logic (0-3.3V) level-shifter and a full-duplex serial connection, adapting the Kenwood PG-4S cable schematic for the TH-G71's 2.5mm and 3.5mm phono plugs. Specific schematic tweaks include changing R1 from 150 ohms to 1K ohm to optimize power from the serial port and adding a 150K ohm resistor between the Radio TXD and ground to manage the 3.3V I/O pin. Detailed plug pinouts for the 2.5mm and 3.5mm connectors are presented, with the interface's TXD connecting to the ring of the 2.5mm plug and RxD to the shield of the 3.5mm plug. Ground connects to the shield of the 2.5mm plug, while the tips of both plugs are no-connects. Debugging procedures cover verifying positive and negative power rails from the serial port, checking component polarities, and testing level-shifting and inversion functions of the interface. Software setup involves enabling "TC ON" (Menu 15 for TH-G71, Menu 9 for TH-F6) and using Kenwood's MCP programming software.

The FTBVR5K software facilitates comprehensive memory management for the Yaesu VR-5000 scanning receiver, supporting operations such as modifying, moving, adding, deleting, masking, and unmasking individual memories. It allows for importing and exporting memory definitions via CSV files, sorting memories by frequency or name, and identifying duplicate frequencies within the receiver's configuration. The program also supports the creation and modification of bank definitions, management of PMS (Programmable Memory Scan) definitions, and adjustment of PMS scanning ranges. Additionally, users can print detailed reports of memories, banks, PMS definitions, rig settings, and S.CALL details, with visual cues like red highlighting for masked memories and yellow for the priority channel. FTBVR5K provides functionality to alter values within the VR-5000's Set and Config menus, and to change S.CALL station names and frequencies. The application operates on standard Windows PCs, including Windows XP, Vista, 7, 8, and 10, requiring an available COM port for transceiver connection, which can be a conventional serial port or a USB adapter. A minimum screen resolution of 800 x 600 is supported, with 1024 x 768 recommended for optimal usability.

This resource details the construction of a mobile screwdriver antenna, patterned after the original W6AAQ DK3 design from 1991. It covers the mechanical and electrical aspects of building a robust, multiband HF antenna for vehicular operation. Specific components discussed include the lower mast section, the coil wound on Schedule 40 PVC pipe, beryllium copper contact fingers, the motor drive assembly utilizing a Black & Decker screwdriver, and the capacity hat design with a brass hub and steel wires. The article provides insights into material selection, such as heavy copper tubing and silicone grease for assembly, and addresses practical considerations like coil length limitations for 80m operation due to lathe size. The construction results in an antenna capable of tuning from 6.5 MHz (40m) up to 6m, with slightly reduced range when the capacity hat is installed. The author describes the mounting base with soldered brass nuts for secure attachment and a U-channel bracket for vehicle mounting on a Dodge Ram 1500. The article includes close-up photographs illustrating the coil, contact fingers, drive mechanism with rubber tubing clutches, and the capacity hat assembly. It also mentions the use of Rustoleum hammer finish enamel for painting the copper pipe, indicating attention to durability and aesthetics.

by USCG navigation center

Supports both PSK31 and PSK63, sends and receives color thumbnail portraits by PSK63, displays 24 PSK63 channels simultaneously, and features semi-automatic mode selection between PSK63 and PSK31. Merely left-click on a PSK63 signal to copy, or right-click on a PSK31 signal to copy.

This program is for editing Memory Channels APRS, SKY COMMAND II and various settings on the kenwood amateur radio TH-D7A(G)/D7A(G2.0)/D7E(G2.0) A similar version exist for TH-D7 generation 1.

The Wireless Institute of Australia (WIA) provides an official directory and database of Australian amateur radio repeaters, detailing their locations, frequencies, and operational status. The resource includes downloadable files in PDF and CSV formats, along with a _Google Earth KMZ_ file for visualizing repeater sites across Australia, including Amateur, CB, and Marine repeaters. It also references external resources for various digital modes such as _IRLP_, _Echolink_, _D-STAR_, P25, Fusion, and DMR, providing links to their respective information sites. The WIA repeater data is cross-referenced with the _ACMA database_ to ensure accuracy, with updates typically occurring twice a year. The directory employs a color-coding system, where purple indicates repeaters carrying the WIA broadcast or callback channels, and a 'W' status denotes operational repeaters with the weekly WIA broadcast. The resource also outlines policies for removing unlicensed or non-operational repeaters from the PDF listing after specific timeframes, while retaining them in the CSV file for potential reinstatement.

Codec2, an open-source speech codec, targets low bit rate voice communication, specifically designed for digital radio applications operating within constrained bandwidths. The project focuses on achieving intelligible speech quality at data rates around 2400 bits per second, a critical parameter for efficient spectrum utilization in amateur radio. Its development addresses the need for robust voice transmission over channels where higher bit rate codecs would be impractical or inefficient. The resource details the technical specifications and implementation aspects of Codec2, including its underlying algorithms and performance characteristics. It provides insights into how the codec processes speech to achieve its low bit rate, outlining the various coding schemes and their impact on voice fidelity and error resilience. The information presented allows radio amateurs and developers to understand the codec's operational principles and its suitability for integration into custom digital communication systems. Applications for Codec2 extend to digital voice modes on HF and VHF bands, enabling more users to share limited spectrum resources. The project's open-source nature facilitates community contributions and widespread adoption, fostering innovation in digital amateur radio. It represents a significant effort to provide a freely available, high-performance speech coding solution for the amateur radio community.

This program is for downloading, uploading the memory channels and various settings on the TS-2000(X)/B2000. To write data to or read the data from the TS-2000(X)/B2000 memory, an RS-232C straight cable is required. Runs on Windows 98.

Examines various facets of online casino gaming, focusing on security, game selection, and payment solutions. It details the extensive gaming libraries offered by online casinos, which often feature over **4,500 games** from more than _75 top software providers_, including slots, live dealer games, and table games. The resource also covers stringent security standards, such as 256-bit SSL encryption and dual licensing from authorities like the _Malta Gaming Authority_, ensuring player fund segregation and data protection. Furthermore, the content explores diverse financial solutions, including traditional methods like Visa/Mastercard and modern options like Skrill, Neteller, and cryptocurrencies such as Bitcoin, with withdrawal times ranging from **0-6 hours** for e-wallets. It highlights mobile gaming experiences optimized for various devices using HTML5 technology, offering over 4,000 mobile-optimized games. The resource also delves into VIP rewards programs, loyalty benefits, and customer support channels, emphasizing quick response times.

DJ-X3 Memory Management Utility - Edit Memory Bank channels (700). Upload / Download, Load / Save Memory Bank channel data, Full / Partial Reset of radio.

LIVE 911 audio of the Chicago Fire Department North & South channels.

Your source for weather radios, communication headsets, 14 channel radios, M&M groovy radios, smithsonian crystal radio and weather station kits, line restrictors, antennas,ham radio accessories, and battery products.

The resource provides specific technical details for Baofeng UV-3R and UV-5R series handheld transceivers, illustrating various hardware configurations. It presents a detailed _speaker microphone pinout_ diagram for multiple brands, including Baofeng, Anytone, Kenwood, and Wouxun, specifying 3.5mm and 2.5mm plug connections for mic, PTT, speaker, and data lines. The page also explains the wiring for dual PTT switching, particularly for the Baofeng UV-82 series, showing how to key either the upper or lower display channel. Furthermore, it offers comprehensive schematics and construction guidance for programming cables, detailing connections for CP2102 USB-UART modules to 3.5mm and 2.5mm plugs, and providing specific configurations for radios like the BTech UV-2501/5001 and QYT KT8900. The content also addresses SMA antenna connections, clarifying SMA Female, SMA Male, and SMA RP types, and discussing issues related to extended antenna threads, suggesting solutions like using a #8 O-Ring to ensure proper contact and prevent transmitter damage. The resource includes a section on troubleshooting erratic charger behavior, attributing issues to poor contact from tension clips and offering a simple fix.

KC9L PSK is a free PSK31 program based on AE4JY’s PSKCore DLL. It supports 5 RX channels, full duplex operation, and more. Even if it's development has been dismissed, is a good tool for windows 95/98 pc.

The Yaesu VX-5R, manufactured between 199x and 200x, offers a transmit frequency range covering 50-52 MHz, 144-146 MHz, and 430-440 MHz for European models, with US versions extending to 50-54 MHz, 144-148 MHz, and 430-450 MHz. Its receiver boasts an impressive wideband capability from 0.5 MHz to 999 MHz, with cellular frequencies blocked in some regions. The unit provides up to 5 watts RF output on 6 meters and 2 meters, and 4.5 watts on 70 centimeters, with selectable lower power settings down to 300 mW. This handheld transceiver utilizes a double conversion superheterodyne receiver system, featuring a 47.25 MHz first IF for FM and 45.8 MHz for WFM. Key specifications include a frequency stability of ±5 ppm across a wide temperature range and a current drain of 25-150 mA on receive. The VX-5R supports 220 regular memory channels with alpha tags, 3 home channels, and 10 NOAA weather channels, all stored in non-volatile EEPROM. Additional features include CTCSS/PL and DCS with tone search, ARS, ARTS, an internal voltmeter, and a Spectra-Scope. The device operates on a 7.2 VDC battery pack or 10-16 VDC external power, weighing 255 grams with dimensions of 58x88x27 mm. The VX-5R was also available as the metallic silver VX-5RS.

Navtex Maritime Safety Information Broadcast Channels

Ham radio frequency list consolidation software. The Ham Radio database can house a unlimited number of records. Holding frequency information from DC to Daylight. The Radio Scanner Database is designed to emulate a radio scanner. A 5,000 record table is provided and is organized by channel number.

Guglielmo Marconi's foundational contributions to wireless communication began in 1894, inspired by Heinrich Hertz's discovery of radio waves in 1888. His initial experiments at his family home near Bologna quickly demonstrated signal transmission beyond line-of-sight, achieving distances up to **two miles** within a year. Marconi secured a patent in 1896, subsequently gaining interest from the British Admiralty after disinterest from the Italian government. By 1899, Marconi's system facilitated transmissions across the Bristol Channel (nine miles) and the English Channel (31 miles). A pivotal moment occurred in 1901 with the successful _transatlantic transmission_, defying the prevailing belief that Earth's curvature would limit practical range to approximately 200 miles. This achievement catalyzed the rapid development of the wireless industry. Marconi continued refining his inventions and, in 1909, shared the _Nobel Prize_ in physics with Karl Ferdinand Braun for their advancements in radio technology.

RACOM is a Czech company specialized in design and production of radio modems and other devices for wireless data networks for radio channels from 140 to 900 MHz. RACOM radio data networks are suitable for data transfer in telemetry & SCADA applications, transaction networks, security systems, IP networks and firts of all mobile tracking and fleet management.

This resource, originally intended to detail the technical specifications of the **Clover** digital communications mode, currently presents a "Page not found" error. The _Clover_ mode was designed for conveying 8-bit digital data over narrow-band high-frequency radio channels, offering robust performance under challenging propagation conditions. Its design focused on efficient data transfer and error correction, making it suitable for amateur radio operators seeking reliable digital links. The absence of the page prevents analysis of specific technical parameters, such as modulation schemes, data rates, or error correction codes that would have been presented. Historically, Clover offered significant advantages in throughput and reliability compared to earlier digital modes over HF, often achieving higher effective data rates than modes like PACTOR or AMTOR under similar signal-to-noise ratios. Without the content, a direct comparison of its performance metrics or practical application scenarios is not possible.

US coast guard frequency list

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.

Nice feature of the Baofeng UV5R family is that they support 6.25kHz tuning steps. That fact makes it possible to dial in the radio to use the exact PMR446 channel frequencies rather than a nearest fit which is the case in many other transceivers.

A 200 kHz bandwidth digital transmission system for image transfer in the Amateur Service is under development, specifically targeting VHF allocations. John B. Stephensen, KD6OZH, leads this project under an FCC Special Temporary Authority (STA) valid until September 10, 2006, authorizing emissions up to 200 kHz bandwidth in the 50.3-50.8 MHz segment. Current regulations typically limit bandwidths to 20 kHz on VHF amateur bands, making this STA crucial for testing wideband digital modes. The modem, a modified **OFDM** (Orthogonal Frequency Division Multiplexed) unit, was initially tested on the 70-cm band. It splits a high-rate data stream into multiple low-rate subcarriers to mitigate multipath echoes. The system uses a DCP-1 card with a Xilinx XC3S400 FPGA and Oki Semiconductor ML67Q5003 microcontroller. The transmitter, located at 36d 46m 30s N, 119d 46m 22s W, generates 150 WPEP into an 8 dBi gain vertical antenna, while the mobile receiver uses a Ham-stick. Three data formats for 50, 100, and 200 kHz channels are being tested, with encoded data rates of 96, 192, and 384 kbps. Verilog code for the VHF OFDM modem is 95% simulated, with modifications from the UHF version including increased filter coefficient precision and a change from Ungerboeck **TCM** to BICM for improved performance over fading paths. Final tests will involve one-way over-the-air measurements of bit error rates and coverage area.