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Explore the detailed setup, essential software, and operational nuances for Greencube (IO-117), a Medium Earth Orbit (MEO) satellite with a 70cm digipeater, offering DX possibilities for amateur radio enthusiasts. From antenna configurations to software choices, this guide covers everything for a successful Greencube experience.

This article provides details on building a 6 Meter J-Pole antenna using PVC pipe for an enclosure.

Construction of an antenna for experimental satellite communication, 8el. (435 Mhz) x 4el. (145 Mhz) Satellite Yagi crossed. No difficulty to built this antenna. Except the gamma match. that requires a little more attention

LB3HC's hightech blog - Amateur radio, RF design, electronics, uC, software, Arduino, AVR, Antennas

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.

RSP1A receiver with LoG (Loop On Ground) antenna in quiet QTH - southeastern Poland. Very low QRM!

An original amateur radio blog in Esperanto lenguage, all about ham radio, DX, antenna.

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.

This blog post details the construction and usage of a 4:1 current balun, using two FT240-31 ferrite cores and 12 bifilar turns. It clarifies common misconceptions about using 4:1 baluns with G5RV antennas and ladder-line to coaxial cable connections. M0PZT emphasizes the importance of proper measurements and the limitations of internal baluns in manual antenna tuners. Detailed instructions and considerations for winding and deploying the balun are provided, along with advice on choosing suitable cores and wire for various power levels and frequency ranges.

Bring the six meters with you during your hoilidays. This article features a portable moxon antenna for 50 MHz used for sota portable operatios

A dual band X-frame wire antenna made using 4 turns for response down to 3 MHz or so, and 2 turns (switched) for response up to around 18 MHz. The loop configurations are tuned using common eBay 365 pF tuning caps.

This article discusses suitable first HF antenna options for amateur radio operators with limited space. It recommends an Off-Center Fed (OCF) Dipole and a Vertical Dipole, detailing the installation processes, considerations for stealth and ease of setup, and the characteristics that make them ideal for newcomers. Safety warnings and maintenance tips are provided to ensure effective and secure operation.

Mad your own simple FS meter. It is the simplest thing to make and is good enough to see if the antenna under test is radiating more power than your old ground plane, old mobile vertical or just radiating at all in a particular direction or in all directions.

The 80-meter Skyloop antenna, a top-performing HF antenna, excels in weak signal work, low-noise operation, and omnidirectional coverage. Ideal for fixed stations, it delivers strong performance at low power, outperforming many alternatives, including 80m half-wave end-fed antennas. Requiring significant space for deployment, it’s well-suited for NVIS and groundwave use. Though not portable, it’s cost-effective and durable, with minor maintenance needs. Tuning may require adjustments for optimal resonance. It’s a standout for base stations, though a lighter portable version could enhance its versatility.

Integrating a **160-meter vertical wire antenna** with an existing 80-meter Yagi system presents unique challenges for Top Band operation. This project outlines the author's experiences with seasonal antenna removal and reinstallation, a necessary task for agricultural land use. It details specific issues encountered, such as incorrect coil sizing and relay configuration problems, providing practical insights into common pitfalls. The article describes the iterative tuning process, comparing **NEC model** predictions with actual on-air performance. It emphasizes the importance of precise measurements and adjustments to achieve optimal resonance and impedance matching. The author shares lessons learned from troubleshooting, including the impact of ground system integrity and feedline considerations. Concluding with an antenna checkup, the resource addresses long-term maintenance aspects, including galvanic corrosion prevention and general upkeep for reliable operation.

a 20M quarter-wave vertical antenna with a 6m telescopic mast, 1:1 balun, and spiral-wound driven element. Designed for QRP at 14.285 MHz, the antenna’s performance exceeded expectations, delivering low SWR and surprisingly quiet reception. Initial testing yielded successful contacts with European stations and EC1KR, showcasing its effectiveness. Compact and easy to deploy, the antenna promises to be an excellent portable solution for future hilltop operations.

Zenith Tracker offers real-time satellite tracking, pass predictions, and radio hardware integration for ham radio operators. The platform includes an interactive world map showing satellite positions, footprints, and ground tracks, as well as a polar radar visualization for detailed pass analysis. Users can view upcoming passes, set filters, and receive notifications. Integration with CSN Technologies S.A.T Hardware and QTRigDoppler allows for automatic radio control, antenna tracking, and transponder management. The platform also offers APRS message interface, grid square-based location input, and API integration for rover activations. Zenith Tracker is recommended for both general users and those needing advanced hardware integration.

Schemaric diagram for a 80m, 40m, 30m, 20m EFHW Antenna Antenna Tuner. The tuner has been designed for an antenna length of 41m and the counterpoise 7.5m.

Build A Shortened 40 Meter Vertical antenna For POTA / SOTA Activations. A project for a portable wire antenna for 40 meters band suitable for POTA or SOTA operations.

This blog chronicles the development of an 80-meter vertical antenna for amateur radio operation. The author constructs a top-loaded vertical using fiberglass poles, achieving significant performance improvements over their previous end-fed wire antenna. Comparative testing using the Reverse Beacon Network and on-air contacts demonstrates 8-10 dB gain on the east coast. The project evolved to include 40-meter capability through a modified design featuring a four-wire vertical cage, loading coil, and strategic guying system. Despite challenges with signal wobble during windy conditions, the vertical consistently outperforms the end-fed wire, particularly for reaching distant stations during nighttime propagation.

This article on basic antenna theory explains why is a 5/8 wavelength vertical antenna better than a 1/4 wavelength antenna

Saluki manufacturer of Spectrum Analyzer, Handheld Spectrum Analyzer, Signal Analyzer, Cable and antenna analyzer, Network Analyzer|RF Signal Generator, Cable Antenna Analyzer

Operating from Banana Island, Sierra Leone (AF-037), the 9L2019 DXpedition by F6KOP and a ten-operator team used the callsign 9LY1JM from January 9-21, 2019. This detailed report covers the logistical challenges, including securing visas and licenses with local assistance from Mark 9L1YXJ and Gregory of Dalton’s Guest House. The team deployed monoband quarter-wave verticals on the beach and two Beverage on Ground (BOG) antennas for Europe/Asia and the USA, operating four stations simultaneously. Technical hurdles encountered included high tides submerging antennas, requiring repositioning, and persistent QRM between closely spaced stations, mitigated by doubling filters. CW signal irregularities at 30-32 WPM were resolved by PC and WINTEST restarts. A significant FT8 logging bug was identified and corrected with on-site software. Despite these issues, the team logged over 4,000 QSOs in the first 24 hours, averaging 5,000 QSOs daily, with a peak of over 6,000 in one day. Propagation varied, with excellent 160m conditions on January 12 yielding over 750 QSOs, and a later four-hour opening pushing the 160m total past 1,600. High bands were challenging due to low solar activity, but mid-bands provided intense pileups and rapid continent-wide contacts. The DXpedition concluded with nearly 50,000 QSOs, including a successful school QSO with Collège Doisneau de Sarralbe (57), managed by F1ULQ and F6KFT.

The author wants a compact, switchable antenna for 40-meter ham radio. They compare 3 designs: rectangle, short-tipped W6NL, and T-hat. All work well electrically, but mechanics matter for a large antenna. The rectangle needs strong support, while the T-hat is sturdier with slightly longer elements. The T-hat design wins for now, but the author will focus on its mechanical details next.

This study details a reception comparison between vertical and horizontal active loop antennas, specifically two identical _Wellgood active loop antennas_, on various HF bands. The experiment, conducted in a densely populated QRM-prone area, monitored FT8 signals over a 24-hour period using two identical receivers. The methodology involved direct comparison of signal reception across the HF spectrum, aiming to identify performance differences based on antenna orientation. The results indicate that vertical loops demonstrated superior performance on higher bands (10m, 15m, 20m), while horizontal loops excelled on lower bands (30m, 40m, 160m), particularly for receiving long-distance (DX) signals. The horizontal loop's advantage on lower bands is attributed to potentially better low-angle performance and reduced sensitivity to man-made noise, yielding a **2-3 S-unit** improvement on 160m. The study provides practical insights for optimizing antenna placement in challenging urban environments, noting that the horizontal loop consistently showed a **10-15 dB** signal-to-noise ratio improvement on lower bands.

This is basic instructions for homemade 4G Antenna working on 2600 MHz UMTS featuring 13 14 dBi gain. This antenna is desigend to resonate on microwave frequencies in two segments from 2500 to 2570 MHz for Uplink, and from 2620 to 2690 MHz for Downlink.

Amateur radio blog about Homebrew equipment,ham radio antennas, satellites, QO-100 operations, rf amplifiers, 2m ldmos amplifier, 70cm ldmos amplifier, 23cm ldmos amplifier

Ground Station offers real-time satellite tracking and radio communication capabilities, primarily for amateur radio operators engaged in satellite operations. It utilizes **TLE data** from sources like CelesTrak and SatNOGS for precise orbital prediction and integrates with various SDR devices, including RTL-SDR, SoapySDR, and UHD/USRP radios, to receive live signals. The software provides automated antenna rotator control and **Hamlib-compatible** rig control with Doppler correction, crucial for maintaining signal lock on fast-moving LEO satellites. It supports IQ recording in SigMF format and decodes several digital modes such as SSTV, FSK, GFSK, GMSK, and BPSK with AX25 USP Geoscan framing. Dedicated interfaces are available for satellite tracking, SDR waterfall displays with live transcription and packet decoding, and telemetry packet viewing. Users can manage TLE data synchronization and SDR hardware, along with browsing decoded outputs through an integrated file browser. An observations dashboard and DSP topology view further enhance the operational experience, providing comprehensive tools for monitoring and analyzing satellite passes.

This guide explores the captivating hobby of shortwave listening (SWL), offering insights for beginners and enthusiasts alike. It covers key shortwave broadcast bands, essential tools like antennas and receivers, and practical tips to enhance listening experiences. Recommendations include budget-friendly SDR receivers, traditional radios like the TECSUN PL-680, and antennas suited for various environments. Additional resources, such as the World Radio & TV Handbook and online tools like Short-Wave.Info, are highlighted to help identify signals and maximize the enjoyment of SWL.

Log periodic Antenna for 23, 13 and 9 cm bands. The LPA was built according to a design by DC8CE and is used for amateur radio television

Discover the success story of creating a 4-meter Delta Loop antenna, ideal for improving radio communication. This horizontally polarized antenna offers efficient performance when mounted at VHF heights, catering to both HF and VHF characteristics. A simple, DIY project suitable for portable setups, providing versatile options for radio enthusiasts.

This project introduces the Loggi, a hybrid antenna merging the wide frequency coverage of log-periodic dipole arrays (LPDA) with the high gain and front-to-back ratio (F/B) of Yagi antennas. Traditional LPDAs span broad frequencies with moderate gain and low VSWR, while Yagis provide high gain and F/B over narrow bands. By analyzing high-Tau LPDA designs, it was found they could nearly match the gain of VHF/UHF Yagis while maintaining excellent patterns, F/B, and front-to-rear ratios (F/R). Optimizing specific elements for target frequencies (e.g., 144.1 MHz) led to the Loggi, which uniquely features all driven elements without passive directors or reflectors. This design effectively functions as a narrowband optimized LPDA, with front elements acting like Yagi directors and rear elements like Yagi reflectors, thus enhancing gain and directional characteristics while retaining broad frequency versatility.

A vertical antenna project for POTA operations. This shortened antenna is aimed to work from 20 to 40 meter band implementing a loading coil, with an additional wire lenght, determined by on field testing and tuning.

Getting started with LoRA a documented experience with LoRA Gateway, Antennas and simple application

The Slim Jim VHF antenna, originally designed by G2BCX, is a folded half-wave dipole fed by a quarter-wave matching section. This version, built from a recycled professional aluminum dipole, demonstrates that various materials—such as copper, brass, or twin-lead—can be used. The article details the antenna’s construction, required materials, and tuning process, emphasizing mechanical stability and ease of assembly. With proper adjustment of the feed point, it provides excellent SWR across the band. Its durability and simplicity make it a practical and efficient VHF antenna solution.

A DIY cantenna can extend your WiFi range by building a 2.4 GHz high-gain antenna using accessible materials. The design, based on waveguide principles, uses a cylindrical tube to capture WiFi signals and can even connect to access points half a mile away in ideal conditions. While the ideal tube diameter was hard to find, a 4-inch aluminum dryer vent was chosen despite theoretical limitations. The cantenna offers a cost-effective, functional boost for your wireless network.

This blog post by VE3VN discusses the design and performance of a 40-meter reversible Moxon antenna. The antenna provides coverage between southeast to west by default, with the ability to reverse for coverage from east to northwest. The post explains how the antenna performs well in various directions, focusing on the Caribbean, South/Central America, the US, and Europe. Detailed measurements and design considerations are shared, highlighting the accuracy of the model and the critical importance of coil inductance. The post also mentions the use of NEC5 for accurate modeling. Overall, this detailed discussion provides valuable insights for ham radio operators looking to optimize their antenna setup.

Explore the design and testing of a cage dipole antenna for 6 meters. Through innovative construction, witness a remarkable 77% increase in bandwidth and improved impedance characteristics.

From March 2 to March 11, 2018, a Norwegian team operated as Z2LA from Zimbabwe, focusing on 160m through 10m bands using SSB and CW modes. The operation, described as "holiday style," aimed to provide contacts for DXers worldwide seeking a rare DXCC entity. Key equipment included a SUNSDR PRO II, an Elecraft KX3, and an Icom 706 MK2G as a spare radio, supported by two Juma 1000 amplifiers for robust signal output across the bands. Antenna systems were tailored for multi-band operation, featuring an Inv L for 160m and 80m, sloping dipoles for 30m/40m, and a _Hexbeam_ from SP7IDX Technology covering 20m to 10m. For improved reception, the team deployed a SAL 30, two reversible BEV antennas from remoteqth.com, and a BOG from K1FZ, enhancing their ability to hear weak signals. QSL information directs operators to Clublog for log search and M0OXO Charles for OQRS, explicitly requesting no bureau cards. The team comprised LA7THA Rune, LA7WCA Arne, and LA9VPA Thor, successfully making numerous contacts and contributing to the DX community's pursuit of _Zimbabwe_ as a DXCC entity.

A C-Pole Antenna for QRPxpeditions describes a DIY C-Pole antenna designed for QRP (low-power) expeditions, inspired by KF2YN’s ground-independent vertical model. After adjustments, it achieved a 1:1 SWR at 14.060 MHz, rising to 2.5:1 at 14.35 MHz. A choke balun, comprising 15 turns of RG8X around a 4” can, was essential for optimal performance. Compact and self-supporting, the antenna enables reliable communication with minimal setup. Contacts included stations across the U.S., and even a 4,600-mile connection to Spain using only 5 watts.

This blog post documents the author's journey building an APRS micromodem for amateur radio applications. Using an open-source design by LY2EN, the author assembled a cost-effective Terminal Node Controller (TNC) with SMD components, an Arduino Nano, and a JDY-31 Bluetooth module. The construction process included PCB fabrication, careful component soldering, microcontroller programming, and Bluetooth configuration. A custom 3D-printed case protected the completed device. Field testing in Romania showed the device functioned with a Baofeng UV-5R radio, though antenna limitations affected performance. The entire project demonstrates an affordable DIY alternative to commercial APRS trackers.

This article focus on the radiation angle of vertical antennas and the fundamentals of electromagnetic wave propagation. The calculation of antenna length at 145 MHz is followed by an explanation of electromagnetic wave speed and the link between wavelength, frequency, and velocity. Author discusses the 5/8th wave vertical antenna, namely its performance and the influence of radiation angle on signal transmission. Figures and analogies demonstrate how different antenna types produce distinct radiation patterns. This highlights the importance of selecting the right antenna for a certain purpose, such as local traffic or dxing. The article discusses a variety of factors that affect antenna performance, including SWR, propagation conditions, and equipment dependability

Medium power BMU (Base Matching Unit) intended for 42 foot to 48 foot vertical, sloper, or Inverted-L antennas.

This article is from the book Ham Radio For Dummies and features some tips for portable amateur radio operations, on Field Day or generic outdoor operation, like selecting the proper antenna and portable power.

In this article, VE9KK discusses the various restrictions faced by ham radio operators when it comes to setting up antennas. The author shares personal experiences and tips on how to overcome these challenges, providing valuable insights for fellow hams. Whether you're dealing with space limitations or neighborhood regulations, this resource offers practical solutions to help you get the most out of your ham radio setup.

Demonstrates the construction and portable deployment of a 40-meter horizontal loop antenna, often referred to as a "Sky Loop" or "DX-Buster." The design adapts a full-wavelength horizontal loop for field use, eliminating the need for traditional insulators by employing four 5-meter heavy-duty _squid poles_ and metal post bases for support. This setup facilitates rapid assembly, crucial for portable operations, with the antenna wire length specified at approximately 43-45 meters for optimal 40-meter band performance. The resource details the specific construction methodology, including winding the antenna wire around rubber caps on the squid poles and securing it with electrical tape. It provides a parts list and assembly techniques, focusing on minimizing components for ease of transport and quick setup. The article, originally published in the February 2013 edition of the Central Coast ARC "Smoke Signals" magazine, reflects practical experience. This documentation offers a field-deployable 40-meter loop antenna solution, utilizing readily available components like fiberglass squid poles. It presents a practical approach for operators seeking a robust, portable antenna for the 40-meter band, emphasizing simplicity and efficiency in its design and deployment.

Building a radio repeater enhances communication by extending signal range and overcoming obstacles like mountains or buildings. This guide explains the fundamentals of radio repeaters, their function, and a step-by-step DIY approach. Key steps include conducting a site survey, selecting an optimal installation location, and configuring the system with suitable equipment such as the Retevis RT97 series. Proper placement, antenna setup, and testing ensure effective operation, making this process accessible for enthusiasts aiming to improve communication reliability and range

Discover how to easily listen to amateur radio bands with insights from Frank SWL, an experienced radio enthusiast. This guide covers essential tips for tuning into frequencies between 10 meters and 160 meters using modern tools like Web SDR and Kiwi SDR. Learn about identifying callsigns, understanding Q codes, and optimizing your antenna setup for better reception. Whether you're a beginner or an experienced listener, this article provides practical advice for enhancing your radio listening experience in 2025.

The resource details the construction of a 433 MHz LoRa APRS iGate and a tracker, both built around _TTGO T-Beam v1.1_ microcontroller boards. Each board integrates an OLED screen, WiFi, GPS, and an SMA antenna connector, powered by an 18650 3.7 V lithium-ion battery or microUSB. The iGate operates on 433.775 MHz, with its status verifiable on aprs.fi, demonstrating practical implementation of LoRa-based APRS solutions. The methodology involves programming the modules using Visual Studio Code with the PlatformIO plugin. This process loads the necessary firmware and a JSON configuration file, which includes the operator's callsign and WiFi credentials for the iGate. The guide emphasizes the ease of programming and provides specific steps for configuration. Initial testing of the iGate and tracker, including smart beaconing configuration, is documented. The low power output of approximately 200 mW from the LoRa board's transmitter is noted, with suggestions for range extension through improved antennas or RF amplification. The author, N4MI, plans to deploy a higher-gain 70cm antenna for the iGate.

Demonstrates the construction of an **ATU-100 (N7DDC)** automatic antenna tuner, detailing the assembly process from component arrival to final enclosure. The resource covers winding the tandem match transformer, connecting the OLED display, and integrating optional control buttons. Specific attention is given to modifying the EEPROM settings for **QRP operation**, reducing the minimum tuning power to 1 Watt, and addressing potential RF interference with CPU by adding capacitors to button connections. The build log includes practical tips such as adapting RG58 coaxial cable strands for PCB mounting and utilizing a repurposed Macbook Pro cover for the custom enclosure. The author references external GitHub pages for comprehensive information, R0AEK's resources for additional details, and a video by MW0SAW for EEPROM configuration across different ATU-100 variants. Future plans involve field testing the completed tuner during SOTA or other portable activations.