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A high G/T Yagi with bent DE for compact contest arrays

STAR-H Corporation specializes in extremely wideband dipoles and compact low-profile antenna systems for military, emergency management, commercial operations and consumer wireless applications.

A compact high G/T Yagi with bent Drive element by DG7YBN

It is very compact, low noise and directive with an impressive 20 to 25 dB front to back

Operating a modern amateur radio station, particularly for advanced digital modes or microwave experiments, often requires precise test and measurement equipment. This resource from NI (National Instruments), now part of Emerson, showcases a wide array of hardware and software solutions designed for demanding test objectives. Their portfolio includes modular instruments and configurable software interfaces, such as _LabVIEW_ and _TestStand_, which integrate AI assistance via _NI Nigel™ AI_ for code completion and sequence building. For those involved in RF and microwave work, the offerings extend to vector signal transceivers, RF signal generators, software-defined radios, and spectrum analyzers. These tools are crucial for characterizing antenna performance, optimizing transceiver circuits, or developing custom radio systems. The company emphasizes its 50 years of innovation, with 40 years dedicated to _LabVIEW_, highlighting a long-standing commitment to engineering solutions. The site also details products for data acquisition, electronic test, and wireless design, covering components like CompactDAQ modules for precise sensor measurements and various communication bus interfaces. Their events and perspectives sections offer insights into topics such as 5G technology and strategies for breaking out of testing silos, providing a broader context for their measurement solutions.

This DIY vertical multi-band Windom antenna offers a practical and effective solution for amateur radio enthusiasts seeking a versatile and compact antenna for HF communications. Its simplicity of construction, multi-band capability, and favorable performance make it a valuable addition to any radio shack. The article provides detailed instructions on constructing the antenna and balun, along with diagrams and component specifications. Field tests demonstrated successful contacts with stations across Europe and North America on 14, 18, and 28 MHz. The antenna exhibited comparable performance to a W3DZZ dipole and outperformed a Cobweb antenna on 18 MHz. Low noise levels were observed, effectively suppressing background noise.

A home made magnetic loop for HF Bands. This small and compact loop is designed to support small power transmissions on HF bands, from 7 MHz to 21 MHz

A very compact and multifunctional digital amateur radio station for the radio operation at home, on the way or in the emergency radio implemented with a Raspberry Pi 4, an Elecraft KX2, a Kenwood TH-D74 and a USB GPS.

This antenna is an off-center fed spiral dipole for 40 meters. The spiral dipole is very compact, making it well-suited for limited space (like an apartment patio), while the off-center feed gives the antenna some multiband capability.

Maker of small and compact multiband QRP UltraLight Magnetic Loop Antennas and UnUn transformer for end-fed multiband antennas

Specialist UK manufacturer of high performance compact HF antennas

The ICOM IC-R72E a neat compact communications receiver. Coverage: LW, MW, SW (0.1- 30.0 MHz continuous) discontinued in 1998

A compact voice keyer for Icom IC-7000

DataBridge wireless RF modem modules facilitate point-to-point data transmission, supporting analog, digital, and serial RS232 UART signals. These modules are engineered for robust wireless communication, offering a reliable solution for various industrial and amateur radio applications requiring secure data links. The product line includes specific models designed for different frequency ranges and power outputs, ensuring compatibility with diverse operational requirements. Each module integrates advanced RF technology to maintain signal integrity over distance, crucial for remote monitoring and control systems. The design emphasizes ease of integration, allowing users to quickly deploy wireless data links without extensive configuration. Key features encompass low power consumption and a compact form factor, making them suitable for embedded systems and portable devices.

Laboratory 599 makers of the DISCOVERY HF/50 MHz SDR Ultra-compact Trasceiver.

The Baofeng UV-5R handheld transceiver, introduced around 2012, operates across the 2-meter (144-148 MHz) and 70-centimeter (420-450 MHz) amateur bands, offering dual-band receive and transmit capabilities. This review provides an early assessment of the radio's form factor, user interface, and general performance, noting its compact size and the inclusion of a **VFO/Memory mode** button for frequency management. The device supports both FM and narrow FM modes, with a reported power output of 4 watts on VHF and 3 watts on UHF, making it suitable for local simplex and repeater operations. Key features discussed include its 128-channel memory capacity, a built-in VOX function, and a **DTMF keypad** for tone dialing and repeater access. The review highlights the radio's ability to scan frequencies and memories, along with a dual-watch function allowing simultaneous monitoring of two frequencies. Battery life is addressed, with the standard 1800 mAh Li-ion pack providing several hours of operation depending on transmit usage. Initial impressions cover the radio's construction and the clarity of its LCD display, which shows both A and B band frequencies.

This is a project aboout compact and portable a QRP antenna tuner for use in the HF ham radio bands from 3-30 MHz, even if it's a compact and efficient project this small antenna tuner will not match any possible load.

Amateur Packet Reporting System (APRS) operations often require compact, reliable solutions for transmitting position data, particularly for mobile or portable stations. This resource details the construction of the _Tiny Track-I_, a transmit-only APRS tracker designed for straightforward integration with a VHF radio and a Global Positioning System (GPS) receiver. It enables hams to broadcast their location without the complexity of a full-duplex TNC. The project outlines the printed circuit board (PCB) layout and schematic, based on an original design by N6BG, with a personal PCB drawing by SV1BSX. It includes specific component placement and notes an additional 10uF/10V capacitor (C5) for improved IC voltage decoupling, a modification not present in the original N6BG diagram. The unit connects to a computer or GPS via a DB9 female connector. This tracker is ideal for basic position reporting, offering a simple and effective way to participate in APRS networks. Its small footprint makes it suitable for vehicle installations or field deployments where space is limited, providing a **reliable 9600 baud** data stream for location updates.

Gimme Five reloaded, a compact 5 band QRP SSB transceiver in SMD technology. This unit covers 5 bands within the amateur radio spectrum (3.5, 7, 14, 21 and 28 MHz). Receiver is a single conversion unit with an interfrequency of 9 MHz. Transmitter uses 5 stages and has got a power level of 10 watts PEP output.

The Buddistick antenna, as demonstrated by KP4MD, effectively handles up to **250 watts** and provides coverage from 40 through 10 meters, with an optional coil extending operation to 80 and 60 meters. KP4MD's video presentation meticulously describes the antenna setup, emphasizing the critical role of the _shunting coil_ for achieving resonance on lower bands like 40 and 80 meters. This practical approach highlights how a compact antenna can deliver solid performance from a constrained location. SWR curve diagrams are included, clearly illustrating the impact of the shunting coil on the antenna's resonating frequency. These visual aids provide concrete evidence of the adjustments needed for optimal operation across different bands, particularly when space is at a premium. KP4MD's insights are particularly valuable for hams operating from apartments or other limited spaces, showcasing real-world results from a balcony installation.

The G3JVL 6M ground plane vertical is a compact antenna that is ideal for portable operations. It packs away into a small bag only 1.3 metres long which is an ideal size for hand-baggage on aircraft.

The NanoVNA is a very compact handheld Vector Network Analyzer. The NanoVNA is tiny and portable analyzer, and it offers a high performance capabilities with an embedded lcd display.

This is a compact three transistor regenerative general coverage receiver with fixed feedback. The sensitivity and selectivity is relative good, especially on the LF and MW bands, as can be expected with this simple design.

DK7IH QRP transceiver for 14 MHz. This small and compact home made transceiver with a max power output of 5W, the VFO module is based on the clock oscillator chip Si5351A by Silicon Labs ATmega168 and OLED 1306

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.

These band filters are based on 3 or 5 sections Butterworth band pass filters, maintaining 50 Ohm impedance, and when built around toroidal inductors, can be made very compact.

This article describes a multi-band antenna design for amateur radio enthusiasts by G3FEW. The antenna is designed to cover at least five HF bands with low SWR and without the need for an ATU. It is also designed to be easy to construct and adaptable for different locations. The antenna is a full-wave dipole with traps at the quarter-wave points. The traps are used to tune the antenna to different bands. The antenna can be fed with a 4:1 balun. The article includes instructions for building the antenna, as well as information on the theory behind its operation. The author also discusses the results of his tests with the antenna. This multi-band antenna is a well-designed and versatile antenna that can be used by amateur radio enthusiasts on a variety of bands. It is relatively easy to construct and can be adapted for different locations.

The Linked Dipole is a multiband antenna designed for 80/60/40/30/20m bands, optimized for the (tr)uSDX low bands configuration. It incorporates a 1:1 Balun to prevent common mode currents, ensuring balanced operation with coaxial cable. The Balun, wound on an FT140-43 core, achieves 37-40dB attenuation. The design includes a 3D-printable housing for compactness and waterproofing, with labeled link insulators for ease of use. Wire lengths were meticulously adjusted for optimal performance with a 7m pole and 3m rope extension, ensuring the antenna's ends are off the ground for improved behavior. The project includes downloadable printables for DIY construction.

The "DIY Telescopic-V Antenna £35" project showcases the creation of a budget-friendly, portable telescopic V-shaped antenna inspired by commercial designs. Using eBay-sourced telescopic whips and custom mounting solutions, the author documents their process, testing, and adaptations. Despite challenges like weather and missing tools, the antenna performed well across multiple bands, enabling successful QSOs. Future improvements include exploring loading coils and testing in better locations. The compact design offers versatility for amateur radio enthusiasts seeking an affordable and practical solution.

The CobWebb antenna project is a compact, multiband HF solution ideal for amateur radio operators. Covering 14-28 MHz, it features a square dipole array with near-omnidirectional coverage and unity gain. This guide details a DIY approach, using a 1:4 current balun for impedance matching. Construction involves aluminum and fiberglass tubing, with optimized element tuning for SWR performance. Weather resistance improvements and resonance shift considerations are also discussed. Build your own CobWebb antenna for an efficient, space-saving HF experience.

In the quest for an ideal field portable antenna, the author recounts experiments involving various wire configurations. While a previous candidate, a 41ft random wire, proved effective but lacked stealth, the search led to a surprising rediscovery of a design previously rejected—the Rybakov Antenna. With a focus on simplicity, rapid deployment, and multiband capability, the author explores the versatility of a 26ft Rybakov, avoiding the halfwave trap. The article delves into the antenna's performance and its potential as a discreet, resonant solution for field operations, addressing the challenges encountered during a POTA activation. Additionally, the Unun/Balun design used in conjunction with the Rybakov Antenna is discussed, providing insights into achieving a balanced system.

The Tri-pole antenna, a clever modification of a standard dipole, allows for dual-band operation by integrating a third element. This design effectively shortens the overall dipole length by 10 to 20 percent, simplifying antenna rotation and offering a compact footprint. KK4OBI's article delves into the operational principles, using a 6 and 10-meter Tri-pole as a primary example, and provides comprehensive instructions for constructing any Tri-pole antenna within the 6 to 15-meter range. Key to the Tri-pole's performance is its off-center feed, necessitating a common mode choke at the feed point for optimal tuning and reduced noise. The author outlines a methodical approach to determining element dimensions, starting with a vertical element frequency calculated as 0.47 times the sum of the desired upper and lower band frequencies. This calculation, along with K-values derived from trend lines, guides the initial lengths for the horizontal arms, demonstrating how a 10m-6m Tri-pole can achieve a total horizontal length 78% shorter than a conventional 10-meter dipole. Tuning and balancing are critical, with the article detailing adjustments to arm lengths and the vertical element to achieve balanced SWR values, as validated through 4NEC2 simulations. Radiation patterns are analyzed at various elevations, showing gains around 5.7 dBi and favorable take-off angles for DX contacts. Construction details specify aluminum tubing dimensions, U-bolts, and an SO-239 connector, emphasizing the importance of a ferrite-based choke for wideband operation.

The DX FT8 is a compact, multiband tablet transceiver designed for FT8 digital mode enthusiasts. Supporting five or seven HF bands, it integrates an STM32F746-based touchscreen interface for standalone operation, eliminating the need for a PC. The latest firmware (v1.9.2) adds SOTA/POTA calling and free-text messaging. Its efficient power design, unique RF amplifier, and 3D-printed case enhance portability. Open-source firmware and community-driven development make it a versatile choice for portable FT8 operation, ideal for SOTA, POTA, and travel use. DX FT8 TRANSCEIVER PROJECT is a collaboration between Charles(Charley)Hill, W5BAA and Barbaros(Barb)Asuroglu, WB2CBA.

The U01 emergency communications antenna is a versatile, multiband antenna designed for 80/60/40/20/17/15/10m bands, known for its reliability and compact size. It features a broadband transformer wound on various core options like FT82-43, FT114-43, or FT140-43, with the latter capable of handling up to 100W. The antenna incorporates a PCB with options for SMA and BNC connectors, and a weather-proofed design for durability. The lightweight construction, using materials like DX Wire UL and Polyester rope, makes it highly portable. The antenna's design has been tested and proven within the DARC Chapter U01, with multiple build options and detailed documentation available for DIY enthusiasts.

Learn how to set up a vertical HF antenna with 5 bands and a quarter wavelength. Discover the benefits of using this type of antenna for ham radio operators looking for a lightweight, compact, and cost-effective solution. Get insights from professional versions like the DX COMMANDER and real-world experiences from other operators. Find out about the MV6 commercial version and its excellent results. Explore different construction methods and receive tips for quick assembly and disassembly. Stay informed with the latest articles and archives on military transmissions and Morse code learning techniques.

This project is for those ham amateurs who do not have a commercial one . It's easy to build with a soldering iron, a plastic case and a little knowledge of arduino. The controller is made with budget components you can find easily in Internet. The main component is a cnc shield that fits over an Arduino Uno. Both made a compact, small and cheap controller.

This project introduces the SN 1/8 mobile antenna, a compact and mechanically stable alternative to traditional 1/41/4 or 5/85/8 wave antennas. Designed for VHF/UHF mobile communications, this 20 cm antenna offers superior performance in moving environments. Its spherical radiation pattern enhances reflections, providing a 2 dB gain. Ideal for vehicle use, it is discreet, easy to install, and resistant to vibrations, making it a practical choice for mobile users seeking reliable and efficient communication. In French.

The CW typewriter is a compact adapter board that transforms Morse code into ASCII characters using an Iambic key. It connects to a computer via USB, emulating the keyboard. The device features inputs for Iambic keying and a WPM speed potentiometer, and outputs for a key and a speaker for side tone. The device can be used with various software and online typing games for practice, offering a unique and interactive way to learn and use Morse code.

This article presents the C-Pole antenna project, a compact, ground-independent vertical antenna designed for amateur radio operators. It features a folded half-wave dipole configuration that eliminates the need for radials, making it suitable for various locations, especially in deed-restricted areas. The C-Pole offers efficient performance with a 2:1 SWR bandwidth of approximately 3%, and it can be easily constructed using common materials. Additionally, the article discusses practical aspects such as feed-point impedance transformation and balun design to optimize functionality and minimize losses.

Eaton provides a comprehensive suite of power quality solutions, ranging from compact single-phase isolation units to high-capacity megawatt sag correction systems. The resource details Eaton's engineering expertise in addressing diverse power quality challenges, emphasizing the distinction between DC resistance and apparent AC resistance under heavy current loads within AC power distribution systems. Specific **Marine-Grade surge protective solutions (SPD)** are highlighted, designed to safeguard critical safety and navigation equipment on vessels and rigs against unpredictable power transients in harsh environmental conditions. The company's commitment extends to providing appropriate solutions for critical power systems, ensuring quality installation. The site also features customer testimonials from entities like Federal Express, Kutztown University, J. C. Penney, and Fairchild Aircraft, attesting to the effectiveness of products such as 'The Protector' in preventing equipment damage and downtime.

A simple superheterodyne receiver (3.5–30 MHz) for amateur radio achieves stable SSB-CW reception using modern BJTs, an AD831 mixer, a 6-pole quartz filter, and Seiler oscillators. Designed with high IF (4.5 MHz), compact AM-FM variable capacitors, and modular resonant circuits, it ensures selectivity, image rejection, and stable tuning. Built in a copper-lined wooden case, it features practical assembly techniques but lacks advanced features like AGC or S-meter. Effective on basic antennas, it achieves global reception.

This tutorial provides detailed instructions for constructing a DIY magnetic loop antenna, ideal for amateur radio operators seeking efficient short wave communication. The design features a remote tuning system utilizing an Arduino and RC servo, making it suitable for indoor use where larger antennas cannot be installed. Magnetic loop antennas are compact and can operate effectively in confined spaces, but they do require careful handling due to the high voltages and currents they generate during operation. Users should possess the necessary technical skills to implement this project safely. The tutorial includes a comprehensive overview of the antenna's theory, specifications, and mechanical design. It outlines the components needed, including a Soviet-made variable capacitor and a digital RC servo for tuning. Safety precautions are emphasized, as the antenna can produce several kilovolts of voltage and high currents. The project is not certified for safety, and users are advised to proceed at their own risk. The tutorial also provides diagrams and explanations of the antenna's operation, making it a valuable resource for both beginners and experienced operators looking to enhance their setup.

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.

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.

Paul McMahon presents a compact VSWR meter designed for QRP portable use, ideal for SOTA operations with rigs like the FT817. The device, constructed from readily available components, employs a simple resistive bridge for wideband performance from 1.8MHz to 52MHz, with diminishing accuracy at higher frequencies. Key features include no need for external power, simple calibration, and operation with low power levels. The design, detailed with parts lists, schematics, and construction guidelines, ensures a 2:1 worst-case VSWR to protect transceivers during antenna matching. Calibration points are set for accurate VSWR readings at various loads.

The Yaesu FT-710 is Yaesu s compact, shortwave transceiver that uses the SDR technology known from FT-DX101 and FT-DX10, which is a great fit for our fast-paced, comfortable world. The FT-710 is a perfect entry-level device. If you're thinking of buying a compact transceiver with SDR technology, it is a good choice.

This innovative antenna tuning unit (ATU) enables QRP operators to match their antennas without transmitting RF signals. Using a noise bridge technique instead of traditional transmit-and-tune methods, it achieves truly silent operation. The design incorporates an L-match network with switched inductors and variable capacitor, handling impedance matching from 3-30MHz. Operating from a 9V battery, it includes a built-in RF power meter and dummy load for QRP transmitter testing. The compact unit is particularly suitable for portable operations where minimal RF emissions during tuning are desired.

A 3.5–24 MHz regenerative receiver for amateur bands was recently constructed, inspired by a 1934 design. The project was both challenging and rewarding, requiring precise tuning and high-quality components. The receiver successfully captured QSOs from across the globe, such as New Zealand communicating with Panama. The simplicity of the design and the satisfaction of building a functional, compact wooden box with handmade resonant circuits were highlights. This project demonstrates a meaningful way to reconnect with the roots of amateur radio.

This project details the construction of a compact, circularly polarized Quadrifilar Helix Antenna (QHA) designed for 146 MHz operation. The antenna features a 1/2λ1/2λ helical design with a 2.6:1 aspect ratio, providing 4.5 dB gain and a spheroid radiation pattern. It is ground plane independent and compatible with both vertical and horizontal polarizations, making it ideal for terrestrial and space communications. The design includes step-by-step instructions for building the antenna using readily available materials like aluminum rods, PVC pipes, and RG-58 coaxial cable. The antenna's performance has been validated through comparisons with commercial omnidirectional antennas, showing superior results.

Showcasing German engineering, ANjo Antennen develops and manufactures a diverse portfolio of amateur radio and commercial antenna products. Their offerings span a wide frequency range from 1.8 MHz to 3000 MHz, emphasizing electrical and mechanical precision for longevity. The company actively participates in events like FUNK.TAG Kassel, providing opportunities for direct engagement and order pickup. ANjo's product line includes high-performance **Yagi antennas** optimized for Tropo and EME, along with multi-stacked Quad antennas designed for contest operations, featuring wide horizontal and narrow vertical beamwidths. They also produce circularly polarized satellite antennas, some with switchable LHCP/RHCP, leveraging their commercial satellite antenna expertise. Beyond amateur applications, ANjo provides flexible, custom antenna solutions for commercial sectors such as BOS, EMC measurements, and telemetry. Their commitment to quality is evident in the Premium-Line antennas, which utilize **1.4301 (V2A) stainless steel** for mast clamps and connectors, ensuring durability and corrosion resistance. They also offer end-fed HF multiband wire antennas, known for their compact footprint and discreet installation.