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High Speed Multimedia (HSMM) radio, as introduced by John Champa, K8OCL, represents a significant advancement in amateur radio's digital capabilities, moving beyond traditional keyboard modes like packet radio. This initiative, driven by ARRL's Technology Task Force, focuses on developing high-speed digital radio networks capable of up to 20 megabits per second. HSMM primarily facilitates digital voice (DV) and digital video (ADV), enabling real-time video transmission from emergency scenes to an EOC without expensive ATV gear, often requiring only a laptop, a PCMCIA card, a digital camera, and a small antenna. The working group's initial efforts concentrate on cultivating microwave skills within the amateur community to build and support portable and fixed high-speed radio-based local networking, or **RLANs**. These networks prove invaluable for RACES and ARES organizations, as well as homeland security and other emergency communications. Field Day exercises and simulated emergency tests (SETs) are encouraged to hone skills in rapid site surveys and deploying broadband HSMM microwave radio networks, with examples like linking Field Day logging stations or antenna test results at the Midwest VHF-UHF Society Picnic 2003. Getting started with HSMM often involves adapting off-the-shelf **IEEE 802.11** (WiFi) equipment to comply with amateur radio regulations, typically operating in the 2.4 GHz ISM bands. While consumer WiFi gear has range limitations under Part 15 rules, proper setup under amateur regulations can extend coverage significantly, with test networks like the Hinternet achieving 5-15 mile ranges at 54 M bit/s using small mast-mounted dish antennas. Careful selection of equipment with external antenna ports, high transmit power, and low receive sensitivity is crucial, along with using low-loss coaxial cable like LMR-400 for optimal performance at these frequencies.

Leader in supplying digital signal processing (DSP) boards, systems, design services and OEM products for the Wireless, Scientific and Defense markets.

Presents amateur radio activities and experiences from JJ0LUU and JJ0LXF, two operators based in Japan. The weblog, hosted on shinshu.fm, documents their on-air operations, equipment setups, and general ham radio interests. Content often includes details about specific contacts, antenna configurations, and local operating conditions within the Japanese amateur radio community. The resource primarily focuses on personal operating logs and occasional technical discussions relevant to their station. It offers a glimpse into the daily life and pursuits of Japanese **amateur radio** operators, detailing their engagement with various bands and modes. JJ0LUU and JJ0LXF share their passion for radio communication, contributing to the broader online repository of individual ham radio narratives. The site serves as a digital logbook and informal platform for sharing their **DXing** and contesting endeavors.

DMR in Helena, Montana. Experiments in Digital Amateur Radio Communications

How test transistors and diodes with a simple digital multimeter.

MARCA, Inc. operates approximately 24 repeaters across Arizona mountaintops and Phoenix-area rooftops, supporting modes like D-STAR and Fusion. The club, holding the **W7MOT** callsign, engages in diverse activities including ARRL Field Day events near Forest Lakes, AZ, ARRL FMT contests, and antenna experimentation. Members actively participate in HF operations such as voice, digital, CW, DXing, and various digital HF modes, alongside MESH and EOC operations within the valley. The club's interests span a broad technical spectrum, from SDR radio building to antique radio restoration, and include modern digital modes like WSPR, WSJT, FT8, and FT4. They also explore computer-based operations such as Echolink, fostering a dedicated Single Board Computer (SBC) and Raspberry Pi group. Monthly VE testing sessions for Technician, General, and Extra Class licenses are conducted by Ray Vasquez, K4RMV. Meetings are held on the third Tuesday of each month, typically lasting two hours, with a business segment followed by a technical presentation. These gatherings occur in-person at IHop in Mesa, AZ, and concurrently via Zoom, accommodating both local members and winter visitors. Informal chat groups often form post-meeting to discuss specialized topics like D-STAR, SDR, APRS, MESH, and Fusion.

Documents S21RC's construction of an impedance transformer harness for a VHF/UHF cross yagi, utilizing 20m of _RG179_ cable. Details the creation of a DIY RF sampler with a -50dB sampling output, primarily for measuring HF radio PA section output with a Spectrum Analyzer, also applicable for _Pure Signal_ transmission. Chronicles the deployment of a 200m long beverage antenna for the _S21DX IOTA_ operation in 2022, positioned 2m above ground. Discusses the construction of a 3-element short beam for 10m to replace a previous 2-element antenna, with assistance from S21DW. Provides guidance on operating cheap _PA-70_ and _PA-100_ type Chinese SSPAs using IRF530 MOSFETs, emphasizing the necessity of a final LPF. Outlines the design and construction of a fully isolated interface for radio-to-computer connections, supporting various digital modes with isolated ground, audio transformers for IN/OUT, optical isolation for CAT/CIV, and isolated PTT/COS lines. Includes a log of software updates, such as the _HMI/TFT for NX8048K070_ and _2.1.14 Lite_ release with bug fixes for PEP hold and gradual watt decay.

Tait Digital Mobile Radio (DMR) is an affordable digital communications platform that delivers a range of workforce efficiencies and operational benefits for mission critical users.

A personal blog about amateur radio activities, including homebrew, bitx, ubitx, mcHF, JT65, FT8 and more digital communications.

How to modify your scanner or receiver with a discriminator output. If you want to decode and monitor digital (FSK and PSK) systems seriously, a discriminator tap is an absolute prerequisite.

Presents various amateur radio topics through blog posts, detailing operational experiences and technical insights from the perspective of SV2YC. The content frequently discusses antenna projects, such as a **portable 20m/40m dipole** designed for rapid deployment, and explores the performance characteristics of different wire configurations in varied field conditions. Observations on propagation and band activity across the HF spectrum are also regularly documented, providing practical context for fellow operators. Specific entries often include detailed accounts of **DX contacts** and participation in minor contests, outlining station setup, power levels, and antenna choices. The blog also covers modifications to commercial transceivers and homebrew accessory construction, offering practical advice on improving station efficiency and functionality. Further posts delve into software applications for logging and digital modes, sharing configurations and operational tips for maximizing their utility in daily amateur radio activities.

The Burlington Amateur Radio Club (BARC) provides a community hub for amateur radio operators in Burlington, Ontario, Canada, offering regular meetings, educational programs, and a dedicated hackspace for electronics and radio experimentation. The club operates several repeaters, including a 2m repeater (VE3RSB) on 147.210 MHz with a +600 kHz offset and 131.8 Hz tone, which supports AllStar node 542490. Additionally, BARC maintains a UHF repeater on 444.825 MHz with a +5 MHz offset and 131.8 Hz tone, and a 1.25m (220 MHz) repeater, facilitating local communication and digital mode access. BARC hosts multiple nets, including a Fusion Net on Mondays at 8:00 p.m. via VE3RSB-Room 61272, a Regular Wednesday Night Net on the VE3RSB system at 7:30 PM, and a 220 Net on Thursdays at 7:00 p.m. The club also runs a CW/SSB HF Net every Thursday at 7:00 p.m. local time on 40m, utilizing 7.125 MHz for LSB and 7.124.3 MHz for CW check-ins. These activities promote on-air participation, technical skill development, and social interaction among members, supporting both VHF/UHF local operations and HF DXing.

Presents the official online presence for CT1ARR, the Associação de Radioamadores do Ribatejo, a recognized amateur radio club based in Portugal. The site serves as a central hub for members and interested parties, detailing the club's objectives and operational scope within the Ribatejo region. It outlines the organizational structure and provides contact information for club officers, facilitating communication among the amateur radio community. The resource documents the club's engagement in various amateur radio activities, including local nets, field days, and participation in national and international contests. It also lists any public service events or training initiatives undertaken by CT1ARR, supporting the development of amateur radio skills and fostering community involvement. The site functions as a digital archive for club news and announcements, ensuring members remain informed about upcoming events and operational changes.

Compact Digital Mode USB Interface. DigiLink Nano is a very compact digital mode Ham Radio interface to connect your rig to a computer or tablet and run virtually any digital mode like PSK31, RTTY, FT-4/FT-8/JT-9/JT-65, Olivia etc.

The home page of WSJT-X Improved, an enhanced version of WSJT-X, the popular tool for hams interested in digital modes such as FT8 and JT65. The software provides enhancements and improvements to the original WSJT-X program, making it easier and more efficient for ham operators to communicate digitally. Whether you are a beginner or an experienced operator, this download can help enhance your digital communications capabilities. Free downlaod and full description of improved features.

Digital ATV from germany

The website for VA3XPR is intended to provide users with information about the VA3XPR repeater, plus news and information related to ham radio digital voice communications.

UK based manufacturer of digital mode PC fully isolated interfaces. Includes several types of interfaces including USB interfaces for CW and Digital modes

The build was an experiment to see if a tube receiver could be stable enough to receive digital shortwave radio broadcasts. The tube acts as both an oscillator and mixer, so the receiver is a type of direct conversion receiver.

This article discusses how volume reduction can help in the reception of weak signals by reducing the noise level. It is commonly known that reducing the volume also reduces the background noise, and especially in the reception of weak digital signals it can be beneficial

Operating on Airplane scattering. Scattering of radio signals by airplanes. An introduction to operating ariplane scattering, using aircraft to redirect RF that would otherwise be lost in space. Antenna Pointing, Doppler Shift/Digital Modes, using digital modes to operate airscatter.

The Narrabeen JOTA and JOTI camp facilitates global communication for Sydney North Region Scouts and Northern Sydney Girl Guides, utilizing amateur radio and internet technologies. Participants engage in two-way radio contacts, often on **HF** bands, to connect with other scouting and guiding groups worldwide, fostering international goodwill and technical skill development. The event integrates both traditional **ham radio** operations and modern internet-based communication methods, providing a diverse experience for youth members. The resource outlines the specific activities undertaken at the Narrabeen site, including station setup, operating procedures, and the use of digital modes for JOTI. It highlights the educational aspects of the event, such as learning about radio propagation, antenna theory, and basic electronics, all within a structured camp environment. The page also provides logistical information relevant to the Australian context of the event.

xCAT is an helper application for the FlexRadio 6000 series running on macOS computers to control via CAT protocol tranceivers, while xDAX purpose is to provide a way for Digital Mode Software like Fldigi, WSJT-X to access the digital audio data (DAX) of the FlexRadioTM

The Covey Hill Amateur Radio Club operates a 146.685 MHz analog repeater with an 88.5 Hz PL tone, alongside several digital repeaters. The resource details specific frequencies and modes for D-STAR (145.590 MHz, 1266.300 MHz voice, 1297.675 MHz data on 23 cm), DMR-Marc (448.525 MHz), DMR-Brandmeister (441.750 MHz), Yaesu Fusion (449.725 MHz), and P-25 Digital (147.315 MHz). It also lists Echolink node 595040 (VE2REX-R) as an access point for the club's network. A recent update, dated June 19, 2024, announces the VE2REX analog repeater and Echolink are fully functional again, after resolving issues including a conflicting 100.0 Hz tone, software repairs for Allstar and Echolink, a suspected defective USB port on the Mini PC, and a faulty exciter in the Motorola Quantar repeater. Guy, VE2VMT, was instrumental in troubleshooting these problems. The club, established in 1994, provides a calendar, news, links, and membership information, with Linda Cullen, VE2NJK, serving as president and VA2DBJ as webmaster.

General informantion and introduction to D-Star explaining what is for D-Start and the practical usage of D-Star in amateur radio communications

A table that summarize all known amateur radio emission modes, with reference to software and platform available for digital modes

Manufacturer of two way radios based in Shenzhen China. Retevis produce commercial, personal and amateur radio handheld and mobile transceivers, either for analog and digital modes. Retevis produce also two-way radio accessories and repeaters.

An optocoupled audio interface between PC and Transceiver for digital modes. The article includes full schematic of complete board and build instructions.

The Meteor-M N2 is a polar orbiting Russian weather satellite that was launched on July 8, 2014. Its main missions are weather forecasting, climate change monitoring, sea water monitoring/forecasting and space weather analysis/prediction. Meteor-M N2 transmits images using the digital LRPT protocol at around 137.1 MHz with can be received with an RTL-SDR.

The use of an isolation interface between the radio and the pc is higly recommended,in order to avoid the problems that could be caused from ground loops. This project includes schematic and assembly instructions

A French website with many resources about digital PMR446 band. dPMR446 et DMR Tier 1 in French

The Digital Communications Interconnect (DCI) resource details the operational philosophy and technical implementation of an open _MotoTRBO_ IPSC network, emphasizing the use of _c-Bridge_ technology for interconnecting DMR repeaters and talkgroups. It outlines the group's mission to facilitate dynamic connections within the regional DMR amateur radio community by openly sharing network resources and talkgroups, promoting independent network growth and exploring the capabilities of c-Bridge linking. The site provides insights into the technical advantages of c-Bridges, such as breaking the finite peer slot limitation of simple IPSC networks and enabling more flexible talkgroup routing beyond two timeslots. This legacy asset, last updated in October 2022, also reflects on the group's history and challenges encountered in national DMR efforts, citing political divisiveness among major c-Bridge groups. It discusses the practical application of c-Bridges for emergency communications and nets, ensuring redundant talkgroup servers for smooth day-to-day operations and priority events. The resource encourages other c-Bridge operators to adopt international talkgroups like "_iCall Talkgroup_" and a nationwide "Emergency Talkgroup," while also offering guidance on affiliating repeaters or IPSC networks with DCI's open network.

Tektronix Signal Generator web site. A Tektronix signal generator can create a virtually unlimited number of signals - analog or digital, ideal or distorted and more.

Home of the DMR Marc, a digital mobile radio network

The sudden explosion of new digital modes has taken the Amateur Radio world by storm. New modes such as PSK31 FT8 JT65 FSK441, ISCAT as well as established modes such as RTTY, SSTV, Hellschreiber and others have rocketed in popularity. In order to use these modes all that is required is a simple computer-to-radio interface which couples the computer soundcard to the radio

This HOWTO explains in detail how you can use the Kenwood TS-590S USB, COM and ACC2 ports for digital operation, set up the radio for digital data and digital voice operation

Aircraft scatter is easily seen on the spectrogram window of digital communication apps, when you know what to look for. Examples of real aircraft scatter usage on six meters band

Learn how to register for a DMR ID on DMR-MARC and Brandmeister

Learn all about FT8 and FT4 digital modes in ham radio. Discover how to configure software to use these powerful modes for making contacts even in poor conditions. Find out how to hunt for awards and view instant statistics of your transmissions. Explore the benefits of using digital modes such as FT8 and FT4 for enhancing your ham radio experience.

The South Manchester Radio and Computing Club (SMRCC) provides a vibrant community for radio amateurs and computing enthusiasts in Sale, Cheshire, UK. Established as an active local club, it hosts regular weekly talks covering diverse subjects within both amateur radio and general computing. Members engage in various activities, fostering knowledge exchange and practical skills development across different facets of the hobby. The club's focus extends to supporting members in their pursuit of radio operating, technical projects, and digital communication methods. With a consistent schedule of meetings, SMRCC aims to be a central hub for local hams and those interested in the intersection of radio and computer technology. The club's activities contribute to the local amateur radio scene, offering opportunities for learning and social interaction.

Start by getting your audio levels sorted out, Having your levels correct is critical to maximum effectiveness in both TX quality and also for being able to decode signals properly. Guide to Filters and other Rig Settings to optimize your output signal

Ucchino is an Italian manufacturer of electronic cirucits inclunding Digiham amateur radio USB interface for digital modes, morse code oscillator, filters and RF protectors

Operating an amateur radio station effectively requires reliable coaxial cable to minimize signal loss between the transceiver and antenna. SIVA Cavi, an Italian manufacturer, produces a range of coaxial cables, including specific 50 Ohm low-loss types suitable for amateur radio applications. Their product line features cables like **RG 58 SHF1**, **RG 213 SHF1**, and **RF 400 SHF1**, which are commonly deployed in HF and VHF/UHF setups. The company also offers specialized cables such as the **HF 214 UF Ultraflex**, a high-performance broadband low-loss 50 Ohm cable designed for flexibility and reduced attenuation across various amateur bands. These cables are engineered with solid or foam dielectric materials, impacting their electrical characteristics and suitability for different power levels and frequency ranges. For instance, foam dielectric cables often exhibit lower loss at higher frequencies, a critical factor for VHF/UHF operations. Beyond amateur radio, SIVA Cavi manufactures cables for digital video broadcast, offshore marine use, and fire detecting systems, demonstrating a broad engineering capability in coaxial cable technology.

This article is designed as an introduction to some of the more popular digital modes. From HSCW to FT8 and interesting article with detailed information on popular and historical amateur radio digital modes.

The Swiss army knife for Digital Voice, the DVMEGA radio is basically a complete D-Star and DMR compatible hotspot

The PJ5 St. Eustatius DXpedition, active from November 16 to November 30, 2019, involved operators SP6IXF and SP6EQZ. This operation targeted Saint Eustatius, designated as NA-145 for IOTA purposes, and focused on all HF bands using CW, SSB, and digital modes. The team logged approximately 23,000 QSOs during their deployment. QSLs for PJ5 contacts are managed via the operators' home callsigns, SP6IXF and SP6EQZ, with _LoTW_ confirmation available. The expedition also participated in the _CQ WW CW_ contest, contributing to the overall QSO count. Additional support came from individuals such as JA1BK, JA3DND, SP5BB, SP5GMM, SP9FMP, SQ7NSN, and KB7MM.

Explains the fundamental purpose of a repeater, detailing how these automated relay stations overcome distance and terrain limitations for VHF/UHF communications. It traces the historical development from early Bell Telephone Labs "relay" stations in 1922 to Art Gentry, W6MEP's, pioneering K6MYK amateur radio repeater in the mid-1950s, which remains active today. The resource clarifies the distinction between simplex and duplex operation, including the unique function of a "parrot repeater" for single-frequency recording and playback. Delving into the internal workings, the guide breaks down a repeater into its core components: the antenna system, feedline (often _Heliax_ or hardline for minimal loss), duplexer, receiver, transmitter, and controller. It emphasizes the critical role of the duplexer in preventing receiver desensitization by isolating transmit and receive signals, even with distinct frequencies. The discussion highlights the importance of high-performance, durable antennas and low-loss feedlines, citing examples of equipment installed in the 1960s and 1970s that are still in perfect working order. Operating a repeater is also covered, with an explanation of frequency offset (e.g., the 600 kHz standard for 2 meters) and the function of _CTCSS_ (PL tone) for access. It outlines standard input/output offsets for various bands, from 6 meters to 23 centimeters, while noting regional variations. The guide also touches on features like autopatch and Digital Voice Recorders (DVRs), providing a solid foundation for understanding repeater technology and usage.

Manufacturer RF coaxial cable assemblies for all purposes including GPS, Wifi, RFID, EMS/Police, Military, & Marine. Coaxial cable assemblies made in Albany, Georgia USA

HF digital mode transmissions, voice transmissions in HF and VHF Bands collected in several XLS files by Relic Radio communications

PSKreporter.info is a highly valuable resource for amateur radio operators using digital modes. It provides real-time reception reports collected from monitoring stations worldwide, covering modes such as FT8, FT4, PSK, and others. The platform offers clear interactive maps and detailed filtering options, allowing users to analyze signal propagation, band activity, and station performance with precision. Its data is widely used to evaluate antenna efficiency, transmission coverage, and propagation trends. PSKreporter.info is easy to use, reliable, and has become a reference tool for both daily operations and technical analysis in digital amateur radio.