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Broadband HF Vertical antenna which does not require a tuner, and which is capable of providing reasonable performance on all bands from 7MHz to 28MHz

The G5RV multiband HF antenna, designed by Louis Varney (G5RV) in 1946, is a popular compromise antenna offering good overall performance on most HF bands when paired with an external antenna tuner. The basic full-size G5RV measures 102 feet across the top for 80 through 10 meter operation and is fed at the center via a 34-foot low-loss feed-stub. This interaction between the radiating section and the feed-stub facilitates matching across 80-10 meters with a standard tuner, often eliminating the need for ladder line directly to the shack. The antenna's design center frequency is 14.150 MHz, configured as a 3/2-wave dipole on 20 meters, with its 102-foot length derived from long-wire antenna formulas. Construction details emphasize the matching section, which can be open wire, ladder line (window-type), or TV twin lead. Each type has a specific velocity factor (VF) affecting its physical length for an electrical half-wave on 14 MHz; for instance, open wire requires 33.7 feet (VF 0.97), ladder line 31.3 feet (VF 0.90), and TV twin lead 28.5 feet (VF 0.82). The article provides formulas for calculating these lengths and discusses the antenna's behavior on individual bands, from 3.5 MHz where it acts as a shortened dipole, to 28 MHz where it functions as two three-half-wave long-wire antennas fed in-phase. Practical construction notes include recommendations for vertical descent of the matching section, sealing the coax junction, providing strain relief, and winding a coaxial choke coil to mitigate common mode current. The resource also presents dimensions for double-size (204 ft) and half-size (51 ft) G5RV versions, along with their corresponding matching section lengths for various line types, making it a versatile reference for hams considering this classic wire antenna.

Optimizing the ZS6BKW antenna for full HF band coverage often requires specific modifications beyond its standard configuration. This resource details several enhancements, beginning with a simple series capacitor to improve 80m SWR, a technique W5DXP found effective for permanent installation due to its minimal impact on higher bands. Further improvements include a 10-inch parallel open stub for 10m resonance, shifting the frequency to 28.4 MHz with an SWR of approximately 1.8:1, a practical solution for Technician class operators. The document then explores a switchable matching section, adding or subtracting one foot of ladder line at the 1:1 choke-balun, which significantly impacts higher frequency bands and eliminates the need for a tuner on 17m. W5DXP's _AIM-4170D_ antenna analyzer measurements confirm these effects. More advanced modifications involve a parallel capacitor for further 80m SWR reduction, requiring remote switching for multi-band operation, and relay-switched parallel capacitors at specific points on the 450-ohm matching section to achieve low SWR on 60m, 30m, and 15m. These detailed steps, including _Smith chart_ analyses for the challenging bands, aim to transform the ZS6BKW into a truly all-HF-band antenna, reflecting W5DXP's practical experience in antenna tuning.

One point eight MHz to 30 MHz is the operational bandwidth for this 4:1 Ruthroff voltage balun, designed to interface an unbalanced T-Match network with a balanced antenna system. The project details the construction using a _T200-2_ powdered iron toroid core, tightly wrapped in PVC electrical tape for insulation, and wound with 17 double bifilar turns of 1.25mm enamelled copper wire. This outboard balun offers flexibility, allowing hams to trial various baluns based on antenna system and impedance characteristics, rather than integrating it directly into the tuner. The resource includes a schematic of the balun, a wiring diagram showing winding connections, and a table suggesting alternative toroid cores like the T80-2 or T400-2 with corresponding winding counts. Component sourcing is straightforward, listing items such as the _Amidon_ T-200-2 core, SO-239 connector, and a sealed polycarbonate enclosure from Jaycar. Performance evaluation was conducted using an _AIM 4170C_ antenna analyser, demonstrating efficient 1:4 voltage transformation across the specified HF spectrum. Further efficiency tests involved measuring RF power loss at various frequencies, revealing minimal loss—less than 0.7 dB from 3.6 MHz to 30 MHz, and only 2.0 dB at 1.8 MHz. These measurements, performed under ideal 50-ohm conditions, confirm the balun's effectiveness as a low-loss interface for multi-band antenna systems. The page also links to several other balun and unun projects, including 1:1 current and voltage baluns, and 9:1 voltage ununs, providing a broader context for impedance matching solutions.

The ZS6BKW multiband antenna, an optimized variant of the classic G5RV, features a 102-foot (31.1 m) horizontal span and a 39.1-foot ladder line matching section. This design, derived by G0GSF (formerly ZS6BKW) in the early 1980s using computer programs and _Smith charts_, aims for improved SWR across multiple HF bands compared to its predecessor. Construction details specify Wireman 554 ladder line and #14 AWG THHN copper wire for the radiators, with precise instructions for determining the velocity factor (VF) of the ladder line using an antenna analyzer or dip meter, ensuring accurate physical length for the matching section. The radiator length is electrically 1.35 wavelengths for the 20-meter band, requiring careful trimming during tuning. Field measurements with an _AIM-4170C_ analyzer by KI4PMI and NC4FB demonstrated good SWR curves and bandwidth on 6, 10, 12, 17, 20, and 40 meters. The antenna was deemed unusable on 15 and 30 meters due to very high SWR, but an LDG AT-100PRO autotuner successfully brought 6 and 80 meters into tune. Contacts were made on 80, 40, 20, and 17 meters, including a **17-meter** contact to Spain. EZNEC models for 80-6 meters are provided, along with an AutoEZ model by AC6LA, which predicted good SWR for 80-10 meters. W5DXP's modifications for an all-band HF ZS6BKW are also referenced.

The X80 multi-band HF vertical antenna, a commercial iteration of the Rybakov design, exhibits a physical length of 5.5 meters, or approximately 18 feet, and is constructed from aluminum tubing. It operates as a non-resonant vertical, requiring an external antenna tuner for impedance matching across its intended operating frequencies. The antenna's design incorporates a 1:4 UNUN at its base, facilitating a nominal 50-ohm feed point impedance for the coaxial cable. Performance observations indicate effective operation on 40 meters, 20 meters, 15 meters, and 10 meters, with reduced efficiency on 80 meters and 160 meters due to its relatively short electrical length for these lower bands. Comparative analysis with a G5RV dipole and a half-wave end-fed antenna reveals the X80 offers a lower take-off angle, beneficial for DX contacts, particularly on the higher HF bands. Field tests conducted with an Icom IC-706MKIIG transceiver and an LDG AT-100ProII autotuner demonstrate the X80's ability to achieve acceptable SWR across 80m through 10m. The antenna's compact footprint and ease of deployment make it suitable for restricted spaces or portable operations, though its performance on 80 meters is noted as a compromise compared to full-size resonant antennas.

This is a video review of the yaesu ft-450 amateur radio transceiver. This radio operates on hf and 6m with a built in antenna tuner.

This is a one for all antenna tuner with wide range tuning on all the HF bands. The tuner is based on a G3WQW design. DIY project by PD7MAA

The Speaky HF SSB transceiver and other homebrew projects Homebrew of radio equipment, antennas, tuner, etc.

With the view to establish a quick and easy multi-band antenna deployment for portable and camping operations a simple long wire antenna with an earth or earth plus counterpoise arrangement with a 9:1 voltage unun including a tuner or simply with a tuner is one possible solution. With the 9:1 voltage unun and wire lengths suggested in the below tables the antenna should present non extreme impedances for all HF amateur band frequencies. This page is far from complete and represents the ongoing investigation into this type of antenna. Experiments to date seem to have raised more questions than obvious answers.

Ten essential tips and truisms for understanding HF antenna: Non-resonant wire dipole antennas fed with open-wire line and an antenna tuner can function effectively as multiband antennas, as detailed in "The Classic Multiband Dipole Antenna" by WB8IMY in March 2004 QST. Coaxial cable, unlike balanced parallel-wire feed lines, can cause RF to travel on the outer shield braid, leading to RF feedback to the station; a 1:1 balun at the dipole center can mitigate this by isolating the unbalanced coaxial feed line. Antenna gain is achieved by shaping and directing RF energy, with beam antennas concentrating power in a specific direction, and wire antennas also exhibiting shaped radiation patterns. An antenna tuner's primary role is to match the transceiver's 50-ohm output to the antenna system's impedance, allowing modern transceivers to deliver full power. Wire antennas do not always require center feeding; end-fed long wires or off-center-fed dipoles (like the Windom) can be used, though they often necessitate an antenna tuner and a counterpoise or radial network. Dipole antennas do not need to be perfectly horizontal; their legs can be bent or inclined, which affects feed point impedance and may require SWR experimentation with coaxial feed. Vertical antennas shorter than a half wavelength require an efficient ground system, typically comprising elevated or buried radial wires, with more radials generally leading to better efficiency. A 1:1 SWR indicates an impedance match but does not guarantee antenna efficiency; an inefficient vertical antenna with a poor ground system can show a low SWR while wasting most RF as heat. Investing in high-quality, low-loss feed line, especially coaxial cable, is crucial for maximizing RF signal transfer and overall antenna system performance.

CG Antenna is a HF radio communication solution manufactory based in China produce automatic antenna tuners, and digital radio interfaces.

There are a large number of antenna designs for HF. One choice out of many is the fan dipole. The ability to transmit of multiple bands without needing a tuner (and even more with a tuner) is a very desirable factor in choosing a versitle antenna for HF.

This Magnetic Longwire Balun (MLB) makes it possible to efficiently use a coaxial lead-in cable with all forms of longwires, T-forms or other types of wire antennas, without the need for an antenna tuner.

The Icom AH-4 autotuner operates efficiently across multiple HF bands, providing seamless automatic tuning for antennas from 3.5 MHz to 54 MHz. Its robust design allows for outdoor installation, making it suitable for field operations and fixed stations. The unit interfaces with Icom transceivers via a control cable, enabling automatic band switching and tuning. The AH-4 is capable of handling up to 120 watts of RF power, ensuring compatibility with most amateur radio setups. Its weather-resistant casing and compact form factor make it a versatile choice for operators requiring reliable performance in diverse environments. Field tests demonstrate the AH-4's ability to maintain low SWR across its operational range, enhancing signal quality and transmission efficiency. Compared to manual tuners, the AH-4 offers significant time savings and ease of use, particularly in rapidly changing band conditions. Its integration with Icom radios simplifies operation, eliminating the need for manual adjustments. The autotuner's performance is consistent with other high-end models, providing a cost-effective solution for amateur operators seeking dependable tuning capabilities without sacrificing performance.

Make and automatic antenna tuner based on Arduino and using economic card. This ATU Project can be installed outdoors and controlled remotely by an rs485 link

The page provides detailed instructions on how to build a 60 meter End Fed Half Wave Antenna Tuner, with large pictures and diagrams. It is aimed at amateur radio operators looking to construct their own antennas for the 60 meter band.

Evaluates the **LDG Z100 autotuner**, a device designed to automatically match antenna impedance for optimal transmission efficiency. The review discusses its performance in comparison to the MFJ-902, noting that while the Z100 is a reliable autotuner, it does not match the range of impedances that the MFJ-902 can handle. The Z100 is suitable for operators seeking a 100-watt autotuner that covers HF bands, providing a practical solution for those who require automatic tuning without manual adjustments. The review highlights the Z100's operational context, focusing on its use in HF bands and its practical application in amateur radio setups. While it offers a straightforward tuning process, the Z100's limitations in impedance matching are noted, making it less versatile than some competitors. This comparison provides valuable insights for operators considering an upgrade or replacement for their current autotuner. The Z100's performance is positioned within the broader market of autotuners, offering a clear perspective on its strengths and weaknesses in real-world amateur radio operations.

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.

1500 watts PEP SSB is the power handling capability of the MFJ-989C HF Antenna Tuner, a popular choice among amateur radio operators. Users have shared a wide range of experiences, with some praising its durability and performance over decades of use, while others criticize its build quality and accuracy. The tuner features a built-in dummy load, SWR-wattmeter, and a balun for balanced line feeders, making it versatile for various antenna setups. However, discrepancies in RF power readings and SWR measurements have been noted, with some users finding the dual scale meter to be off by about 20% compared to a Bird wattmeter. Long-term users report that the MFJ-989C performs well with proper antenna setups, but caution against tuning at high power without initial adjustments at lower power levels. Some have experienced issues such as arcing when exceeding 400 watts, while others have had no problems even at higher power levels. The roller inductor and capacitors are functional, though some users have had to perform maintenance like tightening screws or cleaning components to ensure reliable operation. Despite mixed reviews, the MFJ-989C remains in production, suggesting continued demand. It's a tuner that requires careful handling and possibly some DIY fixes to achieve optimal performance.

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.

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.

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.

Over 100 distinct RF connector types are available from AIR802, including popular UHF series PL-259 plugs and SO-239 sockets, designed for a wide array of coaxial cable dimensions. The company specializes in producing connectors compatible with common amateur radio cables like RG-8, RG-213, and RG-58, ensuring reliable signal integrity for antenna systems and shack interconnections. Their product line extends to various coaxial cable types and pre-made antenna cable assemblies, offering ready-to-deploy solutions for hams. AIR802 also provides custom cable assemblies and pigtails, catering to specific installation requirements for transceivers, tuners, and amplifiers. These pre-fabricated options simplify station setup, reducing the need for field termination of connectors. Michael Bryant is the contact for inquiries regarding their range of RF components, which are essential for building robust and efficient amateur radio stations.

_AT Auto_ is an automatic antenna tuner designed for amateur radio enthusiasts seeking efficient and reliable tuning solutions. This device automates the tuning process, allowing operators to focus on communication rather than manual adjustments. The tuner is compatible with a range of transceivers, enhancing its versatility in different shack setups. Its design incorporates advanced circuitry to ensure optimal performance across various bands. The _AT Auto_ tuner is particularly useful for those operating in HF bands, providing seamless transitions between frequencies. Its integration capabilities with other shack automation products make it a valuable component for modern amateur radio stations. The tuner supports multiple modes, including _SSB_ and _CW_, catering to diverse operating preferences. Its robust construction and user-friendly interface contribute to its appeal among both seasoned operators and those new to the hobby. Kessler Engineering's focus on innovation and quality is evident in the _AT Auto_'s design. The tuner is part of a broader product line that includes shack automation solutions, reflecting the company's commitment to enhancing amateur radio operations. Despite the website redesign, the tuner remains a key offering in their product portfolio.

DF0WD DL4YHF Longwave Station include a linear transverter and antenna tuner

This is a antenna tuner with wide range tuning for antennas with a Z of + 50 Ohms on all the HF bands.

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.

The simple balcony vertical HF antenna made with plastic fishing pole. Just along the pole I install copper wire in 7 meter length. Then was installed ATU. It was used home brew tuner. For each band was used one counterpoise in length 0.8 x lambda/4

256 memories enable the _AT-AUTO_ to recall settings across multiple bands, making it efficient for operators who frequently change frequencies. The tuner is compatible with various antennas and amplifiers, such as the Mercury LUX, and integrates seamlessly with radios like the FLEX 6400 using an RS232-USB connection. This integration allows the tuner to follow frequency changes without additional input, enhancing operational efficiency. Despite being out of production, the _AT-AUTO_ remains supported by Kessler Engineering, which offers firmware updates and repair services. The tuner features a cross-needle SWR meter, providing quick visual feedback during tuning. It also includes a QRO keyline circuit to protect amplifiers during tuning. Users appreciate the tuner's ability to track radios via CAT control, avoiding automatic tuning during QSOs, a common issue with other models. The _AT-AUTO_ is praised for its durability and performance, with many users noting its reliability over years of use. Its ability to handle legal limit power and its balanced line output make it a versatile choice for serious operators. Although it lacks some features like multiple coax outputs found in other models, its robust build and continued support make it a valuable tool for HF enthusiasts.

This type of antenna is a popular antenna design as the performance is very good across the HF bands and requires little or no tuning. It’s a dipole fed off center with a 4:1 balun at the offset feed point. The antenna shown covers 80, 40, 20 and 10 meters. The formula can also be used to adjust the overall length to cover more or fewer bands and the resulting overall length. 160-10m, 80-10m or 40-10 meters depending on your available space. Other bands will require a tuner.

This is an uncommon loop antenna, hombrewed without the small feeding loop. With small spare parts is possible to build a loop antenna tuner for portable usage tha can ben used with common HF QRP transceivers

Originally designed by John Kraus, W8JK in about 1940, this antenna has some interesting properties. The W8JK antenna is 2 (Two) centre-fed double-dipole fed by a pair of anti-phase signals. Small size, simple antenna, offer nice performance but need a tuner. Tested in this project from 30m to 6m bands

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.

A Magnetic Loop Controller project details the construction and operation of an automatic tuning system for magnetic loop antennas, which are resonant circuits using an oversized inductor and an adjustable capacitor. The system employs a stepper motor to precisely adjust the variable capacitor, maintaining optimal resonance across the HF bands. It integrates with various transceivers, including _Icom_, _Kenwood_, and _Yaesu_ models, by monitoring the VFO frequency and adjusting the loop's tuning accordingly. The project provides comprehensive building instructions, a PowerPoint-style presentation, and the full source code for the controller's firmware, enabling hams to replicate and customize the design. The controller's firmware offers diverse functionality, including automatic frequency tracking, manual tuning, and SWR monitoring, significantly enhancing the operational efficiency of magnetic loop antennas, particularly for QRP and portable operations. The design emphasizes accurate capacitor positioning, crucial for achieving low SWR and maximum radiated power. Comparisons with manual tuning methods highlight the benefits of real-time adjustment, especially when operating across different bands or making frequent QSYs. The project's detailed documentation and available source code facilitate experimentation and modification by advanced builders, allowing for tailored performance characteristics.

Author is currently developing the HS4HF 4 Band HF Radio Transceiver with a 5.0-inch TFT display, following their previous HSM1 model. They are also working on the Radio HSDRA, an All Band SDR HF Radio Transceiver with unique features such as DSP Digital Modulation, 100W final power, automatic antenna tuner, and more. The development includes a wide 5.0-inch display, touch screen, and various advanced functionalities. Stay updated with the latest developments in the world of HAM radio with Hambuilder Team.

An cheap and efficient wire antenna for lower HF bands. This closed loop antenna, radiates perpendicular to its plane with a bi-directional radiation pattern. With a gain of 2 dB over a diplole it is a low noise sensible antenna. Requires a tuner if you want to use as a multiband antenna.

The multiband tuned doublet, or center-fed Zepp, is a simple and efficient HF antenna that operates effectively across most amateur bands using a balanced parallel-wire feedline and antenna tuner. Unlike coax-fed dipoles, it tolerates impedance mismatches with minimal loss. By selecting suitable feedline and dipole lengths, one can achieve stable multi-band operation. While it doesn’t match monoband Yagis, it offers excellent performance, low cost, and broad coverage. Its radiation pattern and efficiency vary with frequency, but it remains a practical and versatile solution for HF operators.

7MHz to 30MHz operation is achieved with a magnetic-mounted HF antenna designed for car roof deployment, capable of handling 100 Watts without an external antenna tuner. The design incorporates a large base-loading coil with multiple taps, allowing for frequency selection across various HF bands. This coil effectively increases the electrical length of a short telescopic antenna element, compensating for its inherent capacitance. Construction involves 3D-printed components for the coil former and support structures, though conventional building methods using plastic drainpipes are also suggested. The car body serves as the ground plane, with the coil assembly mounted on a 500mm square metal plate secured by super neodymium magnets. Protection under the magnets is advised to prevent vehicle scratches. Detailed instructions cover winding the 30-turn coil with 2.5mm diameter household electrical cable, assembling the 3D-printed parts, and making soldered connections. Taps are staggered every five turns for precise frequency adjustment. Performance examples include a 7913km contact to Japan using a 1.5m element and 100 Watts, demonstrating low-angle radiation and omni-directional pattern with minimal S-point loss compared to a full quarter-wave.

This page delves into the debate surrounding the End-Fed Half-Wave (EFHW) antenna, exploring whether it is truly a multiband antenna without the need for a tuner. The author investigates the claims and criticisms surrounding these popular antennas, discussing their resonance on various bands and their efficiency for DXCC achievements. The content is valuable for hams interested in understanding the capabilities of EFHW antennas and their performance across different HF bands, with a focus on practical usage and real-world results.

The tri-band trapped delta loop antenna design operates on 80 meters (3.5–4 MHz), 40 meters (7–7.3 MHz), and 30 meters (10.1–10.15 MHz) using a single triangular wire loop. This configuration eliminates the need for an external antenna tuner or band-switching relays. The antenna's physical perimeter, approximately 270 feet, establishes 80M as the fundamental band, with specific trap placements enabling resonance on 40M and 30M. Trap design and placement are critical, with 30M traps positioned inboard of 40M traps within the horizontal element. Each slant leg measures approximately 80 feet. The resource references foundational information from the _ARRL Antenna Handbook_ and _ON4UN’s Low Band DXing_ regarding full-wave loop behavior and feedpoint impedances. The project aims to provide multi-band HF operation from a single, fixed antenna structure.

VE1ZAC's analysis details the performance of **MFJ927** and **SGC239** autotuners with portable HF vertical antennas, specifically comparing 31 ft and 43 ft configurations. The resource originated from challenges encountered during a Maritime QSO Party roving operation, necessitating a lightweight and easily deployable antenna system. Target bands for the contest included 80, 40, 20, 15, and 10 meters, with a maximum power handling of 100 W CW. The author utilized a 30-foot carbon fiber push-up pole to support a vertical wire element, noting its 2 lb weight and reliability. EZNEC modeling was employed to predict performance, showing favorable results for a 30-foot vertical with elevated radials, particularly on 40 and 20 meters. Feedpoint impedance measurements, taken with an AIM4170C, are presented for various HF bands, both with and without a 41-foot RG6 stub designed to reduce reactance on 80 and 20 meters. The stub significantly improved matching on these bands, easing the tuner's workload. Operational tests revealed issues with the MFJ927's reliability during contest setup, leading to reliance on the K3's internal tuner. The SGC239, tested post-contest, performed flawlessly. A detailed side-by-side comparison covers mechanical aspects, connection options, power bias, impedance range, board quality, and documentation. Modifications to the MFJ927, including a new aluminum case, white paint for heat reduction, and upgraded impedance-measuring resistors, are also described.

The POCKET TUNER V1.1 is a highly compact HF T-Match antenna tuner designed for QRPp and QRP portable operations. With a credit card-sized form factor, it is tailored for low-power setups, supporting HF bands from 10m to 40m. The tuner features a unique design using rotary switches for precise capacitor adjustments, allowing tuning in small increments. Its inductance selection is optimized for various bands, ensuring efficient performance. Equipped with a resistive tuning indicator, it protects the transmitter by reducing SWR during adjustments. This versatile and portable tuner is ideal for field operations, enabling efficient antenna matching for low-power rigs.