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Operating within the low-frequency spectrum, transformers serve critical roles in antenna systems, particularly for 160m applications. The resource details the construction and performance of 1:1 transformers built on BN-73-202 cores, emphasizing their use as hybrid combiners or phase inverters for RX antenna arrays. Measurements reveal that these transformers exhibit minimal losses, around 0.12 dB at 1.8 MHz, with variations based on wire type and number of turns. The analysis includes comparative data on transformer performance, highlighting the impact of different winding techniques on frequency response. Notably, the use of coaxial cable for winding improves bandwidth while maintaining low-frequency efficiency. The resource also discusses braid breaker transformers, which minimize inter-winding capacitance, achieving low losses around 0.21 dB at 1.8 MHz. These insights are crucial for optimizing low-band antenna systems, allowing operators to make informed decisions regarding transformer design and implementation.

There are quite a few recipes for building a suitable transformer for an end fed half wave antenna (EFHW), but I was never sure I really understood the main principles. So, I wound a bunch of transformers, made measurements on them using my NanoVNA, learned how to get what I really wanted out of the VNA measurements, and in the process discovered how to build better transformers and be able to predict what they will do

Common-mode chokes are useful solutions for RFI reduction. Winding a few turns of coaxial cable on the FT 240-31 toroid can reduced the noise below the received noise floor. In this article author measure different chokes

Constructed in May 2008, this innovative 4m tall electrically full-size halfwave vertical dipole, tunable to multiple bands, offers HF coverage despite its space-saving design. Inspired by cost-effective DIY alternatives, the antenna design departs from conventional center-fed approaches, utilizing asymmetrical dimensions. Despite resonance challenges, the antenna's performance remains viable, boasting broad bandwidth and adaptability, as demonstrated through SWR measurements and EZNEC predictions.

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.

This article is an attempt to shed some light on this misunderstood component, covering topics like why you need a common mode coke, what it does, what properties it should have, ho to build one and how to measure its performance.

Otto enhances WSJT-X, the popular weak-signal digital modes program for amateur radio. It automates tasks like managing QSOs, prioritizing DX stations, replying to specific calls, and optimizing band usage. Otto works with a modified WSJT-X version (v2.7.0) to add advanced features such as directed CQs, automatic logging, and multi-stream replies. Its intuitive modes streamline operations, while safety measures ensure controlled transmissions. Ideal for DX enthusiasts, Otto improves efficiency and focus, making weak-signal operations more engaging and productive.

RF Power measurement using a DVM, RF Power measurement using an RF detector, RF Power measurement using an Oscilloscope and using a Spectrum Analyzer

This PDF document provides a comprehensive guide on building and using the Moxon Rectangle antenna design for hams. It covers the construction, setup, and tuning of this directional antenna, offering practical advice and tips for amateur radio operators looking to improve their signal reception and transmission capabilities. The guide includes diagrams, measurements, and step-by-step instructions to help hams successfully implement the Moxon Rectangle design for their radio communication needs.

The mini Radio Solutions miniVNA PRO is the only affordable vector network analyser (VNA) I know of that offers remote wireless operation. This is very interesting because it allows to measure the input impedance of HF antennas installed at height without having to deal with coax cable lengths, baluns nor common mode suppression chokes. However, to render the miniVNA PRO truly field proof, it requires a number of significant modifications.

Constructing a 5-element quad antenna, the author aimed for low cost and simplicity, resulting in an effective design with 11 dBi gain and SWR of 2:1 or better across the 2-meter band. Using wood and dowels, the antenna costs under $8 and takes less than two hours to build with basic tools. The model predicts excellent performance, confirmed by ARRL Lab measurements. Practical field results demonstrate improved communication, even in simplex mode.

SNASharp is a free software application designed to work with scalar network analyzers compatible with NWT software from DL4JAL. It is used to measure and analyze the scattering parameters (S-parameters) of microwave devices. Provide several measurements and analysis tools including Smith chart, Polar plot, S-parameter tables, Transmission line calculator

Homebrew a 9:1 transformer and measurement for testing purposes with a miniVNA

It is very worthwhile to understand how Beverages of all types work. Without that understanding it can be quite difficult to interpret what you hear and what you measure.

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.

Method, Units of Measure, and the Dipole Standard of Reference. This article helps in understanding where does beam gain come from in directional aerials like in example Yagi antennas.

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.

This article addresses the issue of unwanted RF in amateur radio setups and introduces a practical method to measure common-mode currents (CMC) using a homebuilt RF meter. The meter, constructed with readily available materials, measures unwanted RF on the coaxial cable shield by inductively coupling to the shield using a split-bead ferrite. The article provides detailed instructions on building the meter, interpreting measurements, and using ferrite chokes to mitigate RF interference. Emphasis is placed on the importance of verifying CMC levels and installing chokes to improve equipment performance.

The Dipole Bazooka Antenna for 40 meters is a popular choice among amateur radio operators. Its design allows for easy construction using materials like RG58 coaxial cable and PVC. Measurements are calculated using specific formulas; for instance, at a frequency of 7,100 MHz, the total length is approximately 19.74 meters. This antenna offers a performance range of 97% to 99%, with an impedance of 49 to 52 ohms. Additionally, it can handle up to 1 kW of power and requires no modifications for connection.

Ferrite E-cores offer a practical solution for constructing baluns, especially when connectors are already mounted on cables. These cores, commonly used in mass-produced pulse transformers, allow for multiple turns without dismounting connectors, making them ideal for control and power supply cables. The material of E-cores is generally suitable for common mode baluns up to 15 MHz, providing a cost-effective option for amateur radio operators. E-cores can often be sourced from old switch-mode power supplies, adding to their appeal for those looking to utilize existing resources. A notable example involves a balun on a USB cable using a Ferroxcube E 32x16x9, 3F3 core with four turns, secured by three cable ties. This setup demonstrates the ease of construction and stability achievable with E-cores. Another example features a balun with eight turns of shielded cable with RCA connectors on the same core, achieving 140 uH inductance at low frequencies. The impedance plot for this configuration is measured between the shield ends, illustrating the effectiveness of E-cores in practical applications. The article includes detailed figures and descriptions, providing valuable insights into the construction and application of baluns using ferrite E-cores. These examples serve as a guide for amateur radio enthusiasts looking to enhance their setups with cost-effective and efficient solutions.

In this article, the current consumption for a selection of popular HF transceiver was examined to determine, via an on the field comparison, whether they were right for portable operation. The radios evaluated include the Yaesu FT-857D, Kenwood TS-590SG, Icom IC-7100, and Kenwood TS-480SAT. The measurements were taken beginning frok 5W in 5W increments up to 100W. The results showed that the Kenwood TS-590SG had the highest current use while the Yaesu FT-857D had the lowest. The current consumption of all radios increased as the power output increased.

This article published on QEX details measurements of tree conductivity and permittivity at HF frequencies, addressing a long-debated topic in amateur radio. N6LF conducted experimental impedance measurements on Douglas fir and maple trees using a vector network analyzer with rings of nails inserted into tree trunks. Results showed that tree conductivity increases with frequency while relative permittivity decreases, similar to soil characteristics. Measured conductivity ranged from 0.06 to 0.4 S/m at 10 MHz, aligning with values used in previous research. These findings validate that NEC modeling can reliably estimate trees' substantial impact on HF antenna performance.

An **Arduino LC Meter** provides an accessible solution for precisely measuring inductance and capacitance values, crucial for RF circuit design, filter tuning, and troubleshooting in amateur radio applications. This project details the construction of a low-cost, accurate instrument using readily available components, making it an attractive alternative to commercial units for hams and electronics enthusiasts. The build process involves assembling a resonant circuit, integrating an Arduino microcontroller for frequency measurement, and displaying results on an LCD. Key components include an Arduino Uno, a 16x2 LCD, a 74HC14 Schmitt trigger inverter, and a few passive components. The design leverages the Arduino's processing power to calculate L and C values from resonant frequency shifts. Calibration procedures are outlined to ensure measurement accuracy, which is vital for critical RF work. The project includes schematics, a parts list, and the necessary Arduino code, enabling hams to construct a functional LC meter for their workbench.

Effective suppression of harmonics and parasitic radiation from HF transmitters is crucial, especially with the increasing sensitivity of VHF/UHF radio channels to interference. This project details a hybrid low-pass filter (LPF) designed to operate across the HF bands up to 51 MHz, making it suitable for 6-meter band operations while providing deep VHF/UHF suppression. The design addresses the challenge of modern interference landscapes, where even microvolt-level signals can disrupt wireless sensors and other simple VHF/UHF receivers. The filter utilizes a single elliptic link, combining high cutoff steepness with robust suppression in the hundreds of megahertz range. A key feature is the use of only two standard capacitor values, simplifying construction and component sourcing. The article provides a detailed schematic, performance characteristics, and _RFSim99_ model file, demonstrating a reflection coefficient S11 below 0.017 (VSWR < 1.03) across 1-51 MHz, ensuring minimal degradation to the antenna system. Construction notes include coil winding specifications and capacitor selection guidance, with recommendations for _FR-4_ assembly. Two capacitor sets are presented, with the first variant recommended for its lower RF current demands, keeping currents below 3 A at 1 kW passing power at 51 MHz. Fine-tuning involves adjusting frameless coils, with considerations for capacitor tolerance and high-frequency capacitance measurement accuracy.

Chavdar Levkov, LZ1AQ, presents an experimental comparison of small wideband magnetic loops, building on his previous work on wideband active small magnetic loop antennas. His research focuses on increasing loop sensitivity by maximizing the short-circuit current, which is directly tied to the "loop factor" M = A/L, where A is the equivalent loop area and L is its inductance. Levkov's methodology involves reducing inductance and increasing area through parallel or coplanar crossed (CC) configurations, comparing these designs against a reference single quad loop of 1 m2 area. Experimental verification included testing three distinct loop types: a simple quad loop, two coplanar crossed (CC) loops, and eight parallel loops, all designed to have a total geometric area of 1 m2. Measurements were conducted at 1.8, 3.5, 7, and 10 MHz using a small transmitter 270 meters away, with a Perseus direct sampling receiver for precise signal level assessment. The results consistently showed that CC loops, particularly Loop 5 (two CC circular loops with 1.44 m2 total area), yielded significantly higher currents, up to 9.1 dB over the reference loop at 3.5 MHz, validating M as a reliable predictor of loop sensitivity. Numerical simulations using MMANA further corroborated the experimental findings, demonstrating an almost perfect correlation between the calculated M factor and the induced loop current for 15 different loop models. Levkov concludes that CC loops offer superior sensitivity for a given loop area, while parallel loops are advantageous for minimizing physical volume. Practical recommendations suggest using loops with an M factor greater than 0.5 uA/pT for quiet rural environments, and he provides a spreadsheet tool, WLoop_calc.xls, to aid in optimizing loop configurations for specific operational needs.

FT-240 toroids measurements. The data was measured using well-calibrated HP instrumentation. All plots have been adjusted to a frequency range of 1-100 MHz on the horizontal axis and a resistance/impedance range of 10-1,000 ohms on the vertical axis. This adjustment facilitates comparison among different materials and aids in determining their suitability for use on the HF ham bands.

This website explains signal variations on a local radio net by tracking the foF2, a measure of ionosphere's ability to reflect radio waves. The website shows daily foF2 variations and how it affects Near Vertical Incidence Skywave (NVIS) propagation for local nets. It also considers D-layer absorption affecting lower bands and F2 MUF distance for long-distance communication. Additionally, the website tracks foEs for E-layer propagation and an EPI index for predicting Es chances.

The F6AOJ RX splitter project was created to split the antenna signal from an LZ1AQ receive loop to multiple receivers, such as radios or SDRs. The design is simple to build and effective. The splitter, mounted on the back of the LZ1AQ control board, provides two outputs—one for an Afedri SDR and another for a K3 transceiver. Measurements show a damping of -3.01 dB at 1 MHz and -3.10 dB at 30 MHz, with a low SWR (max 1.07 at 30 MHz and 1.4 at 60 MHz).

Testing of real antennas is fundamental to antenna theory. The most common and desired measurements are the antenna radiation pattern including antenna gain and efficiency, the impedance or VSWR, the bandwidth, and the polarization. The procedures and equipment used in antenna measurements are described in this page.

The DIY Power Meter project utilizes the _INA226_ high-side power monitoring chip, paired with an ATtiny85 microcontroller, to measure voltage, current, and power, displaying the results on a 128x32 OLED screen. The INA226 communicates via an I2C interface and is programmed with a calibration factor based on the shunt resistance and current register LSB. The project is designed to handle a maximum current of 500mA using a 0.16ohm shunt resistor, which can be adjusted to a 0.2ohm resistor, reducing the full-scale current range to 409mA with a resolution of **12.5uA**. The shunt resistor dissipates only 33mW at maximum current, making 1/4 watt resistors suitable for the setup. The PowerMeter.ino sketch configures the shunt resistance and maximum design current, automatically calculating the calibration factor. The project can be prototyped on a breadboard using an Arduino Uno, employing the Wire library for INA226 and OLED communication, and the u8g2lib library for the OLED display. For the ATtiny85 version, the Adafruit-TinyWireM and Tiny4kOLED libraries are used. The power meter is independently powered by a 3V CR2032 cell, with power switching options including manual switches or DC switched jacks. The low-side n-channel MOSFET switch configuration is tested but introduces voltage drop issues, making manual switching a more reliable option until a suitable DC switched jack is found. DXZone Technical Profile: INA226 | ATtiny85 | OLED Display | Power Meter

This project presents a compact QRP SWR meter featuring a 0.96" OLED display (128x64 pixels) for high-contrast visibility, updated with software fixes for display compatibility, improved low-power performance, and support for ATtiny45/85 microprocessors. A 1.3" OLED version accommodates visibility needs. Designed for HF QRP transmitters (3-15W), it uses a Breune coupler with germanium diodes for accurate SWR measurement. Powered by a AAA battery, the meter offers a standalone solution for impedance matching, with a 3D-printed enclosure enhancing portability.

An FT-817 ceased transmission on the VHF 2m band, despite the other HF, UHF, and 50 MHz bands operating correctly. Suspecting an excess of input signal during FT-8 mode transmission, they conducted measurements with an oscilloscope, revealing a burnt-out PIN diode, identified as D3003, type HSU277, on the PA unit board. Following the replacement of this surface-mounted diode, their FT-817 resumed operation on the 144 MHz band.

Delta loop antennas, particularly the 30 meter variant, offer unique advantages in terms of vertical polarization and omni-directional coverage. The construction process detailed by VE3VN highlights common mechanical and electrical challenges faced by amateur radio operators. Key design considerations include minimizing interaction with existing contest band antennas, achieving low elevation angles for DX chasing, and ensuring the antenna remains off the ground for agricultural clearance. The article provides specific measurements, such as the loop's height and feed point impedance, which are critical for optimizing performance. The use of NEC modeling software illustrates the importance of accurate resonance calculations, revealing how proximity to the tower affects both pattern and impedance. This practical account serves as a resource for hams looking to build effective antennas while navigating typical construction hurdles.

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.

This project goal is to construct a versatile and informative RF power meter. The user-friendly interface, comprehensive power measurement capabilities, and AM detection function make it a valuable tool for various RF applications

Detecting stray RF voltages on station grounds, chassis, and interconnecting cables is crucial for preventing program and hardware failures in the shack. This article details the construction and application of an LED RF V-probe, which offers significantly higher sensitivity compared to conventional neon lamp indicators. The probe leverages two specific properties of modern red LEDs: their ability to glow at microampere currents and their rectification capability at frequencies up to tens of megahertz. The design features a simple circuit with two LEDs, allowing for indication of both positive and negative RF voltage half-waves. The minimum detectable RF voltage is approximately 2 V, a substantial improvement over the 40-60 V threshold of neon bulbs. The resource illustrates the probe's physical construction on a PCB and provides a direct comparison demonstrating its superior sensitivity in detecting RF fields near a coil. Two operational modes are described: a non-contact mode for high RF voltages (above 15-20 V) and a direct-contact mode for measuring lower RF voltages, with a safety caution for the latter. Practical examples show the probe's use in analyzing RF voltage distribution across a radio station setup at 1.84 MHz and 24.9 MHz, revealing insights into common-mode current issues and the effectiveness of mitigation strategies like adding radials.

Explore the world of fox hunting with the Fox Hunt V7 Kits and Assembled Units. Learn about the different antennas used for fox hunting, such as the tape measure beam with an offset attenuator. Discover how to make your own WB2HOL beam antenna using PVC pipe, T's, and a tape measure. Find out how the offset attenuator works and how it can help you track down jammers and interference. Whether you're a seasoned fox hunter or just starting out, this page offers valuable insights and tips for improving your hunting skills.

This page provides basic information about SWR (Standing Wave Ratio) and its importance for ham radio operators. It explains what SWR is, how to measure it, and why it is crucial to have a good SWR reading. The content covers the impact of SWR on antenna efficiency, power transmission, and potential interference issues. It clarifies common misconceptions like the impact of coax length on SWR. Suitable for hams looking to optimize their radio setup and avoid performance issues due to SWR issues.

This report details a modification of a Diamond V2000 antenna, replacing its original two 0.50 m radials with two 1.55 m radials. Initial M5-threaded rods failed to fit; the housing required M6 threads. Custom radials were made using 8 mm OD aluminium tubing and M6-threaded stainless steel ends, secured with nuts machined to 9 mm. SWR issues on 6 m (>2:1) were largely due to a poor counterpoise connection, resolved during reassembly. NanoVNA measurements showed no adverse effects on 2 m or 70 cm. The final setup retains the two 1.55 m radials and original counterpoise. Other operators reported SWR degradation with similar mods—sometimes fixed by adding capacitance—but this was not observed here.

This is a group to exchange views, help and ideas for improvement of the Automatic Magnetic Loop Controller, as described at VE2AO web site. The Automatic Magnetic Loop Controller tunes a Magnetic Loop Antenna in real time, tracking every movement of the Transceiver VFO, by polling the Transceiver for frequency information and calculating an appropriate Capacitor position accordingly. The Controller can also perform Automatic Tuning based on SWR measurement.

Guide to constructing an effective antenna for 50MHz. Inspired by a design from Martin DK7ZB, the article emphasizes the importance of precise measurements and quality materials. With a 2.20m boom and careful assembly, the antenna promises excellent performance, resilience, and cost-effectiveness, making it ideal for six meter band operations.

This comprehensive article dispels common misconceptions about Standing Wave Ratio (SWR) in amateur radio. The author explains that SWR is not an antenna property but a measure of the entire antenna system, representing the mismatch between transmission line and load impedance. Contrary to popular belief, modest SWR values (under 3:1) typically cause minimal power loss in HF applications. The article demonstrates mathematically why obsession with achieving 1:1 SWR is often unnecessary, explains when SWR matters more (QRO, QRP, VHF/UHF), and explores effective matching techniques including proper ATU placement and quarter-wavelength transformers.

Online Coil Inductance Calculator. To calculate the inductance of a single-layer, air-core coil, just select the measurement units, enter the number of turns, the coil diameter and the coil length.

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.

Learn how to easily convert between different units like dBu, dBm, W, mW, V, and uV with the dBCalc application. This small windows program allows ham radio operators to quickly check conversions using input and output resistance. It's a useful tool for anyone dealing with electronic measurements and calculations. Best of all, dBCalc is free to use, making it a convenient solution for amateur radio enthusiasts. This tool simplifies complex conversions and helps hams optimize their equipment setup.

The article discusses the construction of a UHF band-stop stub filter to protect an APRS receiver from potential damage during a balloon launch. The author, who communicates using a 441 MHz transmitter, needed to ensure that the RTL-SDR dongle receiving at 144 MHz wouldn't be damaged by the transmissions. The solution involved creating a quarter-wavelength open stub filter using coaxial cable, which attenuates the 441 MHz signal while allowing the 144 MHz signal to pass through. The filter's design is based on the principles of constructive and destructive interference, with careful measurement and trimming to achieve the desired frequency response. The final filter provided 34.8 dB of insertion loss at 441 MHz and minimal loss at 144 MHz, effectively protecting the receiver.

The ICOM IC-R75, introduced in 1999, operates on 13.6 Volts DC and measures 241 by 94 by 229 mm. Its coverage spans from 30 kHz to 60 MHz, making it a versatile receiver for various bands. The review details available accessories, including optional filters and the **UT-106 DSP module**, which significantly enhances signal processing capabilities. Performance comparisons are drawn against other notable receivers such as the Drake R8B and earlier ICOM models, providing context for its audio quality and overall functionality. User feedback is integrated, offering practical insights into its daily operation and reception characteristics across the spectrum. This analysis offers an in-depth look at the IC-R75's technical capabilities and features, serving as a valuable reference for operators interested in this **legacy receiver**.

Twenty 1-watt carbon film resistors are configured in parallel to construct a 50-ohm **dummy load** for amateur radio applications. The design incorporates a heatsink for thermal dissipation and an **SO-239 connector** for RF input, making it suitable for QRP operations. This budget-friendly project details component selection, soldering techniques, and mounting procedures, achieving a continuous power rating of 10 watts and intermittent handling of up to 100 watts across HF and VHF frequency ranges. The resource provides a step-by-step guide for assembly. This construction offers an economical solution for essential shack tasks such as antenna tuning, transmitter testing, and SWR meter calibration without radiating an RF signal. The utilization of readily available components significantly reduces the overall build cost compared to commercial alternatives, providing radio amateurs with a functional and reliable test accessory. While specific VSWR measurements are not provided, the design prioritizes practical utility for low-power transceiver diagnostics and general RF experimentation.

This resource presents a non-rigorous evaluation of the front-to-back (F/B) ratio of short Beverage antennas, specifically designed for low-band operation on frequencies such as 160, 80, 40, and 30 meters. The author, VE1ZAC, details the methodology used to measure the F/B ratio, which involves using a Millen Grid Dip Oscillator as a portable signal source. Measurements were taken by switching the antenna direction and recording S Meter and preamp readings to derive gain numbers. The document discusses the challenges faced in achieving accurate measurements and the assumptions made during the process, such as the calibration of S Meter units at 6 dB. This evaluation is particularly relevant for amateur radio operators interested in antenna performance on low bands.

This article describes a DIY RF field strength meter project inspired by VK3YE's "The Squeakie" design. The device, built around a 555 timer IC and a 1N4148 diode, converts RF signal strength into audible tones with proportional pitch. The author enhanced the original design by adding volume control, LED indication, and digital readout capabilities using an Arduino Nano and LCD display. The completed project functions as a versatile RF detection tool, suitable for antenna testing and fox hunting, while offering multiple output methods: audio, visual, and digital measurement display.