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Operating a ham station often involves encountering radio frequency interference (RFI), RF feedback, or RF burns, which are frequently misattributed to poor equipment grounding. This resource meticulously dissects these assumptions, asserting that RF grounds on the operating desk often merely mask more significant system flaws. It identifies five primary causes for RF problems, including antenna system design flaws, proximity of the antenna to the operating position, DC power supply ground loops, equipment design defects, and poorly installed connectors or defective cables. The content emphasizes that issues like "hot cabinets" or changes in SWR when connecting a ground indicate substantial RF flowing over wiring or cabinets, a phenomenon known as common-mode current. The article provides detailed explanations of common-mode current generation, particularly from single-wire fed antennas like longwires, random wires, and OCF dipoles, which inherently present high levels of RF in the shack. It also illustrates how vertical antennas, lacking a perfect ground system, can excite feed lines with significant common-mode current. Through simulations, the author demonstrates how a dipole without a proper _balun_ can cause RF problems at the operating desk, showing current patterns and voltage distributions on feed line shields. The discussion extends to the proper application of _RF isolators_ and _ferrite beads_, clarifying their role in modifying common-mode impedance on cable shields and cautioning against their use as a band-aid for fundamental system defects. The resource advocates for correcting the actual source of RF problems, such as antenna system issues or poor connector mounting, rather than relying on internal shack grounding or isolators. It highlights that properly functioning two-conductor feed lines, like coaxial or open-wire lines, should result in minimal RF levels at the operating position, even without a desk RF ground. The author shares personal experience, noting that his stations since the late 1970s have operated without RF grounds at the desks, relying instead on proper antenna system design and feed line integrity.

This project involves the construction of a 5 Watt Morse code beacon transmitter that operates in the 28.200 to 28.300 section of the 10 Meter Amateur Radio band. The beacon controller uses an Arduino Uno microprocessor board to produce the three signals that control the transmitter.

Reviews from eHam users about the all band all modes Yaesu Transceiver

The BTech DMR-6X2 dual-band DMR handheld radio is thoroughly reviewed, detailing its features and performance for amateur radio operators. This resource covers the radio's capabilities for both VHF and UHF frequencies, supporting Tier II DMR digital and FM analog modes. It highlights key specifications such as its **136-174 MHz** and **400-480 MHz** frequency ranges, CTCSS/DCS, DTMF, 2-TONE, and 5-TONE signaling, and its _digital simplex repeater_ function. The review provides a comprehensive unboxing experience, listing included accessories like two Li-Ion batteries (2100 and 3100 mAh), a programming cable, and a 37-page English user guide. It also specifies the radio's physical dimensions of 5.1 x 2.4 x 1.5 inches and weights of 9.9 oz with the 2100 mAh battery and 10.8 oz with the 3100 mAh battery, offering practical insights for hams considering this transceiver.

Constructing a compact directional antenna for the 17-meter band, this resource details the build process for a Moxon rectangle, a two-element Yagi variant with folded-back elements. It covers the antenna's evolution from the _VK2ABQ beam_ and provides specific dimensions for a version built using fishing pole whips. The content includes a discussion of the antenna's radiation pattern, feedpoint impedance, and its inherent front-to-back ratio, which is often superior to a standard two-element Yagi. Practical considerations for element spacing and material choices are also addressed, alongside a visual representation of the antenna's physical layout. Performance data presented includes a comparison showing the Moxon rectangle's **2.5 dB gain** over a half-wave dipole and a front-to-back ratio of **20 dB**. The resource also touches upon the antenna's relatively wide bandwidth for a two-element beam and its suitability for portable operations due to its compact footprint. It offers insights into optimizing the design for specific operating conditions and discusses the advantages of its lower take-off angle compared to omnidirectional wire antennas, making it effective for DX contacts on the 17-meter band.

Over 15 years of operational notes are documented on the AA6E Station Log, covering diverse amateur radio topics. The blog presents detailed accounts of station setup, antenna experiments, and digital mode operations, often featuring specific equipment like the _Ten-Tec Orion_ transceiver. It includes practical discussions on **station grounding techniques** and insights into PSK31 Morse code communication. The resource provides a chronological record of Martin Ewing's amateur radio activities, offering firsthand perspectives on equipment performance and operational challenges. Content often includes technical observations and solutions developed through practical experience, such as optimizing antenna systems for various bands. Specific entries detail contest participation and DX chasing, providing context for operational decisions and results.

Amateur radio operators seeking local community and emergency communications involvement often look for active clubs. The Rock River Radio Club (RRRC) provides a platform for hams in Wisconsin to participate in weekly nets and monthly meetings, fostering camaraderie and operational readiness. Their activities include regular ARES/RACES nets, which are crucial for maintaining proficiency in emergency communication protocols and equipment. The club hosts weekly nets on both VHF/UHF and HF bands, allowing members to practice various modes and frequencies. These include a Monday evening net on the Juneau Repeater at _146.64 MHz_ (PL 123.0) and a Thursday evening net on the Knowles Repeater at _442.975 MHz_ (PL 123.0). An HF net operates on Saturdays at **3.947 MHz**, with an additional ARES/RACES net on Sundays at **3.967 MHz**. Monthly club meetings are held on the first Tuesday of each month at 7 PM in Randolph, Wisconsin, providing a consistent gathering point for members and prospective hams. The club also engages in public demonstrations, such as those at the Experimental Aircraft Association (EAA) Dodge County Chapter Fly-In, showcasing amateur radio to a broader audience.

A interesting guide to help get started with HF published at Essex Ham

A review of all possible receiving antennas for top band 160 meters

A simple, cheap and easy to build 26 feet long vertical antenna that works DX on 20 - 10 meters including WARC Bands, it is designed for portability for field days, camping, or permanent installation, cost, and to achieve at least 1/2 wavelength on the WARC bands.

The article, "Using 75 Ohm CATV Coaxial Cable," details methods for employing readily available 75-ohm CATV hardline in standard 50-ohm amateur radio setups. It addresses the inherent impedance mismatch and practical considerations, such as connector compatibility, for hams seeking cost-effective, low-loss feedline solutions. The resource specifically contrasts common 50-ohm cables like RG-8, RG213, and _LMR-400_ with 75-ohm hardline, highlighting the latter's lower loss characteristics, particularly at VHF and UHF frequencies. It explores two primary approaches to manage the impedance difference: direct connection with an acceptable SWR compromise and precise impedance transformation. The direct connection method acknowledges that a perfect 1:1 SWR is not always critical, especially when using low-loss coax. For impedance transformation, the article explains the use of half-wavelength sections of coax to reflect the antenna's 50-ohm impedance back to the transmitter, noting its single-frequency effectiveness. It also briefly mentions transformer designs using toroid cores and a technique involving two 1/12 wavelength sections of feedline for broader bandwidth. The content further clarifies the concept of _velocity factor_ for calculating electrical versus physical cable lengths, providing a generic formula for precise length determination. It notes that while half-wave matching is practical for 10 meters and above, it can result in excessively long runs for lower bands like 160 meters, potentially adding **250 feet** of cable. The article also mentions achieving a usable bandwidth of 28.000 MHz up to at least **28.8 MHz** on 10 meters with specific transformation techniques.

Pictures of a homemade monoband linear amplifier for 160m band powered by 3 x QB5/1750

A low-band receiving antenna that can fits in a 30-foot circle

These are QRP rated 3 Pole Butterworth filters based on a design by K4VX, feature simplicity, almost no insertion loss, and reasonable rejection on the other ham bands.

The antenna in this project is a modification of the techniques used to design a multiband fan type dipole with little or no tuning involved having a total space of 105 feet

FRARS is a local ham radio club based in Poole, Dorset and has members active on all bands from 73KHz to Light!

Cheap but effective multiband quad antenna covering the entire horizon on 10-12-15-17-20m bands.

Reports indicate the PA1RBZ DX Cluster, previously accessible via telnet at pa1rbz.dyndns.org on port 9000, is no longer operational. The QSL.net hosting platform displays a 404 error, indicating the specific page or file for the cluster's web interface or related information is missing. This service was designed to provide amateur radio operators with real-time DX spotting data, facilitating long-distance contacts across various bands. The cluster's primary function was to aggregate and disseminate DX spots, allowing users to monitor current propagation conditions and identify active stations. Such systems are crucial tools for DXers and contesters, enabling rapid response to new openings and rare DX entities. QSL.net, which hosts over 30,000 amateur radio websites, provides these services free of charge to hams, relying on user donations for operational continuity.

A very popular method of making a short dipoles resonate at a given frequency. This type of antenna is suitable for single band, narrow bandwidth use.

The AT-AUTO automatic antenna tuner handles 1.5kW CW operation, employing stepper motors under microprocessor control to precisely position a roller inductor and air-dielectric variable capacitor, avoiding relay-switched discrete components. This design choice prevents loud relay clacking and burning contacts, a common issue with competing products. The tuner features auto-retuning capabilities and receives periodic firmware updates, ensuring continuous improvement and added user-requested features. Its companion product, the _CX-AUTO_ coaxial switch, also features an embedded microprocessor controller. It enables selection of 1-of-8 coaxial outputs via a serial data interface. When integrated with the _AT-AUTO_, the tuner can associate specific coaxial outputs with amateur radio bands, automatically commanding the _CX-AUTO_ to select the correct antenna when the operator QSYs to a different band. Don Kessler began designing the AT-AUTO in 2005, with its debut at the 2006 Dayton Hamvention. Kessler Engineering also offers custom RF product design and electrical engineering consulting, specializing in Class-E RF amplifiers.

Over 20 distinct discussion categories are available on the Amateur Radio Discussion forum, encompassing a wide array of topics relevant to radio enthusiasts in the UK and beyond. The platform facilitates exchanges on technical aspects of amateur radio, including antenna designs, equipment reviews, and operating practices across different bands. Specific sections are dedicated to CB radio and shortwave listening, broadening its appeal beyond licensed amateurs. The forum's structure supports detailed discussions on operational challenges like the "Work All Postcodes" award, which encourages contacts across UK postal districts. Members can track personal statistics, manage contacts, and engage in challenges, fostering community participation and skill development. The resource provides a centralized hub for sharing knowledge and experiences among radio operators, offering practical insights into diverse radio communication facets.

MorseExpert 1.15 decodes Morse Code audio to text, leveraging algorithms from CW Skimmer for optimal performance on weak, fading signals amidst interference on amateur radio bands. It processes audio from the device's built-in microphone or an external radio receiver via cable, optionally highlighting Ham callsigns and keywords. The application features a waterfall display with a bandwidth of 200-1200 Hz, decodes frequencies between 300-1100 Hz, and supports keying speeds from 12-45 WPM with automatic CW pitch detection. Recent updates include support for Android 15, edge-to-edge mode, improved stability, and a pause decoding button. A premium version offers an ad-free experience and user-selected text colors. Users can switch between General Text mode and Ham Radio QSO mode, which enhances word segmentation and highlights callsigns. The app also includes a frequency lock mode, text selection capabilities for copying, sharing, or saving decoded text, and provides guidance on reducing acoustic echo and constructing an audio attenuator for optimal radio interfacing.

A home made 4 element yagi antenna that can be easily adapted for 10 meter band

The K9IU Indiana University amateur radio club provides a robust station environment for its members, located within the Indiana Memorial Union. This setup includes a variety of radio resources, making it accessible for students and faculty interested in two-way radio communication, from local ragchews to international DXing. The club's facilities are available for use at any time, fostering an active amateur radio community on campus. Members can engage in various aspects of the hobby, utilizing the club's equipment for operating on different bands and modes. This hands-on access supports learning and practical experience in radio theory and operation, which is crucial for new hams and seasoned operators alike. The K9IU club serves as a central point for amateur radio activities at Indiana University Bloomington, aligning with the university's broader academic and extracurricular offerings.

Operating the UoSAT-2 (OSCAR-11) satellite, launched in 1984, presents unique challenges due to its age and current eclipse schedule. This resource provides a historical archive of news, telemetry data, and specialized software for decoding its 145.826 MHz FM beacon. It includes tools like _CTERM_ for terminal emulation and capture, and U2TM for processing ASCII telemetry, enabling hams to analyze the satellite's health and performance. The site also offers audio samples of the beacon and S-band signals, along with details on hardware and software decoders. Reception reports are actively solicited for the satellite's intermittent transmissions, which occur for less than an orbit every 21 days during its eclipse period. The site details how to process raw telemetry data, including instructions for skipping initial frames to improve decoding accuracy with U2TM. It also provides software like SATILL for predicting solar eclipses and tools for determining the satellite's spin period from magnetometer or solar array telemetry, offering insights into its operational status despite its advanced age.

Isotron antennas are antennas of reduced size, without tuning. On 40 and 80m band, it is made of two plates into v whose angles are connected by a coil. In this article the description of a home made realization for the 40m band.

Eham reviews of the dual band kenwood TH-D7a/e series handheld transceiver

Measuring the output impedance (Zs) of solid-state broadband HF amplifiers operating in class AB eham article by ZS6BIM

The Kenwood TS-870S HF transceiver features two state-of-the-art 24-bit 20 MIPS DSP chips, providing over 100dB out-of-passband attenuation and CW bandwidth adjustable to 50 Hz. It operates across 160-10 meters with 100 watts output, incorporating digital filtering, a beat canceller, and 100 memory channels. The radio also includes a transmit equalizer, RX antenna input, and a K1 Logic Keyer, enhancing signal processing and operational flexibility for amateur radio operators. Advanced capabilities include IF stage DSP, dual noise reduction, and an auto notch filter, all contributing to superior signal reception and clarity. The TS-870S offers a variable AGC, voice equalizer, and an RS-232C port for computer control, with Windows™ software supplied. Its built-in automatic antenna tuner functions on all bands for both transmit and receive modes, streamlining station setup and operation. Available accessories such as the DRU-3A digital recording unit, SO-2 high stability crystal oscillator, and VS-2 voice synthesizer option further extend the transceiver's utility. The unit requires 13.8 VDC at 20.5 Amps and is supplied with an MC-43S hand microphone, making it a comprehensive station component.

The IZ3MEZ Web DX Cluster presents real-time amateur radio DX spots across 20 distinct frequency bands, spanning from **LF (2190m)** at 135.7 kHz up to **SHF (QO-100)** at 10499 MHz. It displays the DX callsign, frequency, DXCC entity, spotter callsign, and spotter DXCC entity, along with any accompanying comments. The cluster also lists various operating modes such as CW, RTTY, FT8, FT4, FT2, PSK, and SSTV, and supports special operating activities like QRP/P and specific award programs including IOTA, POTA, SOTA, WCA, and JOTA. The cluster's interface provides a dynamic feed of the latest 50 spots, continuously updated with precise timestamps. It offers direct **Telnet protocol** access for users preferring a command-line interface, with configuration instructions provided. The resource also integrates with other spotting networks like RBN and PSK Reporter, enhancing its utility for DXers and contesters seeking propagation information and activity monitoring across a broad spectrum of amateur radio frequencies.

Italian prefix maps and band plans, includes links to antenna plans and many ham radio resources.

Fifty-three digital modes, including PSK31, RTTY, and JT65, are explored in this resource, providing detailed descriptions of their underlying technologies and typical use cases. It covers error correction methods like ARQ in PACTOR and FEC in JT65, alongside modulation schemes such as FSK and PSK. The content highlights the evolution of digital communication from traditional TNC-based systems to modern sound card implementations, emphasizing the role of personal computers in advancing these modes. Specific modes like AMTOR, PACTOR, and G-TOR are discussed, noting their baud rates and error correction capabilities. For instance, AMTOR operates at 100 baud, while PACTOR offers 200 baud with Huffman compression. The article also delves into newer modes like MFSK16, which uses 16 tones and continuous Forward Error Correction, and Olivia, capable of decoding signals 10-14 dB below the noise floor. Each mode's bandwidth, speed, and resilience to propagation challenges are examined, such as MT63's 1 KHz bandwidth and 100 WPM rate, or Hellschreiber's 75 Hz bandwidth and 35 WPM text rate. The resource also lists predominant USA HF digital frequencies for bands like 160, 80, and 40 meters, specifying segments for PSK31, RTTY, SSTV, and Packet. It includes links to freeware and shareware sound card software such as Digipan, FLDigi, and MixW, enabling amateurs to experiment with these modes.

This resource documents numerous QRP (low power) portable amateur radio operations conducted by W1PID, Jim Cluett, primarily from various outdoor locations in New Hampshire. The content includes detailed accounts, photographs, and operational specifics for over 350 individual "QRP Adventures," often involving hiking, biking, or kayaking to remote sites. Each entry typically highlights the location, date, bands and modes used (frequently CW on HF), and notable DX contacts made with minimal power, sometimes as low as 200mW WSPR. The site serves as a chronicle of practical QRP field operation, demonstrating successful DXing and contesting from challenging environments. It showcases diverse operating scenarios, from mountaintops like Cannon Mountain and Knox Mountain to lakeshores, riverbanks, and even marine mobile operations. The documented contacts span numerous DXCC entities across Europe, Asia, and the Americas, providing empirical evidence of QRP's efficacy in varied propagation conditions and terrains. Specific events like the Worked All Germany contest, 13 Colonies Event, and CWT sprints are also featured.

Ham radio and cb radio italian only web site dedicated to amateur radio and citizens band

In this article, author examine stresses placed on common-mode chokes (aka baluns) as hams use/abuse them, examine the efficiency of simple dipole multi- band antennas and their feed systems. Stressing a Balun.

Explains the annual Jamboree on the Air (JOTA) event, a global amateur radio gathering for Scouts and Guides. This activity connects young people worldwide through ham radio, fostering international friendship and introducing them to radio communication technology. Participants use various amateur radio bands and modes, including HF, VHF, and digital modes like FT8 and JS8Call, to make contacts with other JOTA stations and learn about the hobby. The ARRL provides resources for Scout leaders and amateur radio operators interested in hosting a JOTA station, including guidelines for setting up temporary stations, safety protocols, and educational materials. The event typically occurs on the third full weekend of October, aligning with the World Organization of the Scout Movement's (WOSM) global schedule. JOTA emphasizes hands-on experience with radio equipment, antenna theory, and basic operating procedures. It serves as a significant public service opportunity for hams to engage with youth and promote the educational aspects of amateur radio.

This project details the construction and testing of a M0PLK Delta Loop antenna for the 20-10m ham radio bands. Inspired by positive reviews highlighting its reduced local QRM compared to Cobweb antennas, the author built the antenna using aluminum tubes, DX-Wire FS2 wire, and a 1:4 balun. A mix of custom 3D-printed parts and careful assembly ensured stability and performance. Initial VSWR measurements met expectations, and test QSOs demonstrated success across multiple bands. Future enhancements include adding a lightweight, remote-controlled rotator for directional capabilities.

Installing a mobile rig in a vehicle requires careful planning and execution to ensure optimal performance and safety. The process begins with selecting the right equipment, such as the ICOM IC706MKII for low bands and the ALINCO DR-610 for VHF/UHF operations. Proper mounting is crucial; both radios are strategically placed under the back seat of the Silverado, allowing for a clean installation while maintaining passenger comfort. The Hustler antenna, equipped with various resonators, ensures coverage across multiple bands, while the LDG automatic antenna tuner fine-tunes the match for efficient operation. A remote head for the tuner enhances accessibility, making adjustments easier while driving. Each step of the installation is documented to provide insights and tips for fellow operators looking to enhance their mobile setup. The experience shared here reflects practical knowledge gained through hands-on work, aiming to inspire others in the ham community to undertake similar projects.

A technical explanation of what is a mesh node in HSMM-Mesh HamNet, with explaination of specific roles of each network interface

The Mississippi QSO Party, sponsored by the Mississippi Section of the ARRL, offers a prime opportunity for hams worldwide to make contact with Mississippi stations. This annual event encourages both in-state and out-of-state operators to activate Mississippi counties, promoting activity across the Magnolia State's diverse geographic regions. Participants often operate from various locations, including parks and historical sites, contributing to the unique character of the contacts. Operators typically utilize a mix of HF and VHF bands, employing CW, SSB, and digital modes to maximize their QSO count and multiplier acquisition. The exchange usually involves a signal report and county for Mississippi stations, or state/province/country for others. Results are compiled and published, recognizing top scorers in various categories and encouraging friendly competition among participants. The event serves as a significant annual gathering point for the Mississippi amateur radio community, fostering camaraderie and operational skill development.

The TS-690 was Kenwood All Mode Multi Band HF Transciever

The Kenwood TS-450S is a formidable transceiver covering 160 through 10 meters including the WARC bands with 100 watts input

The VU2BBB repeater, located in Matheran, Maharashtra, commenced operations in the late 1980s, a significant undertaking by the Bombay Repeater Society. This repeater facilitates VHF and UHF communications for local amateur radio operators, providing extended range and improved signal reliability across challenging terrain. Its establishment marked a key development in regional amateur radio infrastructure, offering a crucial node for local nets and general QSO traffic. The repeater's operational parameters include specific input and output frequencies within the 2-meter band, typically utilizing a standard offset. CTCSS tones are often employed to mitigate interference and ensure selective access for authorized users, a common practice for repeaters in densely populated areas. Regular maintenance and upgrades ensure _VU2BBB_ remains a reliable asset for the amateur community, supporting emergency communications and daily amateur radio activities. The _Bombay Repeater Society_ continues to oversee its operation, reflecting a sustained commitment to local ham radio services.

HA8DU European manufacturer of quality amateur radio antenna tuners for HF Bands, from 10 meter to 160 meters band. Products includes manual and automatic antenna tuners, power handling till 3.5 KW. HA8DU produce even custom made variable capacitors and rotary switches.

Interesting article about amateur radio mobile installation for HF VHF UHF bands in a Toyota Tacoma truck

The Kitchener Waterloo Amateur Radio Club (KWARC) website provides a central hub for its members and the broader amateur radio community, detailing club activities, meeting schedules, and special events. It features a monthly newsletter, the _Kilowatter_, which archives club news and technical articles, offering insights into local amateur radio operations and projects. The site also includes information on the club's repeaters, operating on various bands, and details about the annual _Central Ontario Hamfest_. Content covers diverse aspects of the hobby, from general interest articles to specific technical discussions. The resource serves as a primary communication channel for KWARC, facilitating member engagement and disseminating information about club-sponsored activities like field days and public service events. It also lists contact information for club executives and provides resources for new licensees.

An experimental prototype of an asymmetrical hatted vertical dipole antenna that can work on HF bands 20 to 10 meters band. The AHVD Vertical dipole is an upside-down T design

A QRSS beacon on 30 meter band project wind and solar powered based on a loop antenna.

The **LDG Z100 Autotuner** review by GW6ITJ details the unit's practical application and performance in a ham shack environment. Initially acquired to replace an MFJ-902, the Z100 is noted for its ease of use, though the author observes it doesn't quite match the impedance range of the older MFJ unit. This hands-on assessment provides a real-world perspective on its capabilities for 100-watt operation across the HF bands. GW6ITJ specifically mentions the Z100's suitability for 3.5 MHz and higher frequencies, indicating its utility for common HF operations. The review focuses on user experience rather than technical specifications, directing readers to the LDG website for detailed data and manuals. This approach highlights the tuner's operational characteristics from a user's perspective. The author's experience with the Z100 suggests it's a reliable choice for general amateur radio use, particularly for those seeking a straightforward autotuner. The comparison to the MFJ-902 offers a valuable benchmark for hams considering a similar upgrade or new acquisition, emphasizing practical differences in impedance matching.

HamGear.eu page about the FT-100, 160 to 6 meter bands plus the 144 MHz and 430 MHz bands transceiver from Yaesu.