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The Superphaser-2 is an antenna phasing unit based on the PSA-A Phase Shift Amplifier module

The 160-meter amateur radio band, spanning 1.8 to 2 MHz, was historically the lowest frequency amateur allocation until the introduction of the 630-meter and 2200-meter bands. ITU Region 1 allocates 1.81–2 MHz, while other regions use 1.8–2 MHz. This band, often called "Top Band" or "Gentleman's Band," was established by the International Radiotelegraph Conference in Washington, D.C., on October 4, 1927, with an initial allocation of 1.715–2 MHz. Effective operation on 160 meters presents significant challenges due to the large antenna sizes required; a quarter-wavelength monopole is over 130 feet, and horizontal dipoles need similar heights. Propagation is typically local during the day, but long-distance contacts are common at night, especially around sunrise and sunset, and during solar minimums. The band experienced a resurgence after the LORAN-A system was phased out in North America in December 1980, leading to the removal of power restrictions.

How do two-wire reversible direction Beverages work, an excellent document that explains fundamentals of beverage antennas. This article details the design and performance of a reversible beverage antenna. Leveraging orthogonality between common mode and differential mode currents on a 2-wire line, this antenna facilitates independent reception from both ends. While common mode signals arrive and are summed on a transformer's secondary for common mode reception, differential mode signals induce anti-phase currents, providing individual reception. Various measurements explore impedance, transmission loss, and F/B ratio, highlighting the antenna's effectiveness and areas for improvement. Notably, increasing the antenna's height significantly improved performance.

Wideband receiving phased arrays with small electric or magnetic active wideband elements are discussed in details. Practical results and examples are given.

This page is a short description of the four phased verticals system for 160m 80m and 40m

FMI provides superior solutions in the design and manufacture of frequency control devices including Voltage Controlled Temperature Compensated Crystal Oscillators (VCTCXO), voltage controlled crystal oscillator (VCXO), Temperature Compensated Crystal Oscillators (TCXO), crystal clock oscillators, high temperature oscillators, surface mount and crystal oscillator products, phase locked sources and more.

The WB5RVZ Genesis Radio G40 build log documents the construction of a 5W QRP 40m SDR transceiver kit, detailing each phase of assembly from power supply to RF filtering. It provides specific component lists, parts placement diagrams, and testing procedures for stages like the local oscillator, Tayloe detector, and RX op-amps. The resource highlights discrepancies between documentation versions and offers practical advice for builders, including a "virtual build" approach to preemptively address potential ambiguities in component identification and placement. It also addresses a specific "VK6IC Fix" for early board revisions, involving trace cuts and jumper wires for improved performance. The build log presents measured voltages and expected current consumption for various stages, such as the 4.9-5.0 Vdc on the 5V rail and under 100mA for RX current. It outlines critical adjustments like image rejection tuning, a common procedure for direct conversion receivers. The resource also includes practical tips for handling components like the 2N3866 transistor and its heatsink, emphasizing pre-assembly. It details the winding of two 1.45 uH toroidal inductors on T50-6 cores with 17 turns of #20 AWG wire, crucial for the RF path.

Article on Phase-cancellation of noise on 2m band

We are amateur radio operators on the Central California coast participating in all phases of amateur radio

The 2200-meter band (135.7-137.8 kHz) presents unique challenges for amateur radio operators due to its narrow 2.1 kHz bandwidth, low signal levels, and high noise. W1TAG explores various transmission modes suited for this demanding environment, highlighting that traditional voice modes like SSB and AM are impractical. Plain old CW serves as the baseline, demonstrating effectiveness across different modes, though signal-to-noise ratio (SNR) significantly limits practical speeds. The article notes that reducing CW speed below 5 WPM can improve copy, especially with computer-aided spectrum analysis software capable of decoding signals too weak for human ear reception. QRSS, or "CW sent slowly enough that speeds are best expressed in seconds per dot," is a key mode for LF work, with examples ranging from 3 seconds/dot to extreme 240 seconds/dot transmissions. _Argo_ by I2PHD is mentioned as a simple program for QRSS, enabling reception of signals like BRO, a Part 15 beacon, at a distance of **1100 miles**. Other modes discussed include Dual Frequency CW (DFCW), which uses frequency shifts to distinguish dots and dashes, and Binary Phase Shift Keying (BPSK), a phase modulation technique employing 0 to 180-degree phase flips. WOLF (Weak-signal Operation on Low Frequency), a specialized BPSK form by KK7KA, encodes 15-character messages into 960-bit packages, taking 96 seconds to transmit, and has demonstrated successful reception over **672 seconds** for a message from a 1-watt beacon. Further modes include PSK, FSK variations like JASON and MSK, and graphical modes such as Hellschreiber and Chirped Hell. The article concludes with a practical chart comparing the time required to send a simple message like "WD2XES FN42CH " across these diverse LF modes, offering valuable insights for operators planning contacts on the low bands.

PhaseFree, Inc. Surge Suppression. Provide customers with the safest and highest quality surge suppression on the market. Providing surge suppression for the Navy's MARS stations protecting their investment.

Rotatable Antenna with Phased Elements based on the orignal design concept of HB9CV antennas, is considered to have an higher gain than standard quad antennas. The Swiss Quad Antenna does not need any spreader or boom.

The collinear antenna, or Marconi-Franklin antenna, is an omnidirectional, high-gain antenna composed of in-phase half-wave dipoles aligned vertically. By using quarter-wave transmission line segments, it maximizes gain at a low horizon angle, outperforming a half-wave dipole. Adding segments increases gain but narrows bandwidth. A popular DIY version, the CoCo antenna, uses half-wave coaxial cable segments connected by non-radiating transmission lines. Built with stable velocity factor cables, a matching quarter-wave sleeve balun, and ferrite rings for attenuation, the antenna achieves performance comparable to commercial models.

Power transformers for electronic, toroidals,three-phases

Phased Spaced Active Whips and Broadband Loops by WA1ION

Manufacturer for splitter and combiners, baluns, directional couplers hybrid couplers, modulators, mixers, phase discriminators, antenna feeds.

This antenna was conceived mainly for high-speed digital transmission via satellite. The antenna is made of two full waves loops , mounted at right angles to each other. Then coupled together, 90 degrees out of phase over a horizontal circular reflector. With this configuration the antenna is omni directional and circularly polarized.

Operating in the **microwave** spectrum, Response Microwave, Inc. specializes in the design and manufacturing of RF and microwave signal processing components and subsystems. The company's product line encompasses a wide array of offerings, including Connectivity Series components, rotary joints, phase shifters, cable assemblies, surge protectors, terminations, Hybridline/Couperline products, circulators/isolators, directional couplers, quadrature hybrids, attenuators, custom assemblies, filters/diplexers, DC blocks & bias tees, power dividers/combiners, laser diodes & drivers, high-frequency connectors, and precision test accessories. This extensive catalog supports various applications requiring precise signal manipulation and transmission at elevated frequencies. The resource provides access to a comprehensive product catalog and a dedicated connector catalog, detailing specifications for components like **high-frequency connectors** and test cables. While specific performance data or comparative analyses are not directly presented on the main page, the breadth of products indicates a focus on providing foundational building blocks for microwave systems. The company emphasizes customer service and aims to be a reliable source for RF/Microwave/Optics product requirements, serving a growing customer base with its specialized component offerings.

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.

Building the Three-Element Hex Beam. A project and construction phase of an HF hex-Beam antenna using trees to hang the antenna and a Channel Master antenna rotator.

Custom EMI Filters, AC DC Three phase filters by Filter Concepts Inc.

Demonstrates MegaPhase's extensive product line of RF and microwave coaxial cable assemblies and components, engineered for demanding applications up to 110 GHz. Key offerings include _Test & Measurement Cables_ with superior phase and amplitude stability, _RF & Microwave Cables_ utilizing _GrooveTube®_ technology for high power systems, and a range of RF components like directional couplers and power dividers. The site details specific cable types such as _Alumibend™_ for space-qualified, ultra-light applications through 90 GHz, and armored cables designed for rigorous environments up to 50 GHz, emphasizing their robust mechanical strength and measurement repeatability. The resource highlights applications across diverse sectors, including space programs like the _Hayabusa_ mission, global security (C5ISR), military airborne systems (MIL-T-81490), telecom, and automated testing. It also provides technical insights through "How To" guides on measuring amplitude/phase stability vs. flexure and proper connector cleaning. The company's commitment to quality is underscored by its rigorous testing protocols and a strong warranty, ensuring reliable operation in critical systems.

The resource, "Conventional Use of Transmission Line," meticulously details the operational principles of transmission lines, emphasizing the Transverse Electromagnetic (TEM) mode of energy transfer. It clarifies that for a line to function purely as a transmission line, all currents must be confined internally, with external fields ideally zero. The discussion differentiates between balanced and unbalanced lines, asserting that while both require equal and opposite currents within the conductors, the key distinction lies in the voltage relationship of each conductor to the surrounding environment. It highlights that a good antenna pattern does not inherently confirm proper feeder balance, and that common-mode currents can lead to RF in the shack and increased noise levels, even without pattern distortion. The article further explains that a transmission line can become a radiating conductor if energy is applied in a non-TEM mode, leading to common-mode issues. It cites classic texts like Jordan and Balmain's "_Electromagnetic Waves and Radiating Systems_" and Kraus's "_Antennas_" to support its definitions of TEM mode operation. The content also explores non-transmission line applications of parallel or concentric conductors, such as _coaxial dipoles_ and _folded dipoles_, which intentionally operate in non-TEM modes for antenna functionality. The author, _W8JI_, stresses that simply measuring equal currents is insufficient to confirm a balanced feeder; phase and voltage balance to ground are equally critical.

A Phased Array Switchbox by ComTek founder K8UR, switch your 4-Square in 8 directions and control it remotely over the internet

Low-frequency (LF) radio time signals, operating primarily in the 40–80 kHz range, are broadcast by national physics laboratories for precise clock synchronization. Transmitters like **JJY** (40 kHz, 50 kW; 60 kHz, 50 kW), RTZ (50 kHz, 10 kW ERP), MSF (60 kHz, 15 kW ERP), WWVB (60 kHz, 50 kW ERP), RBU (66.66 kHz, 10 kW), and DCF77 (77.5 kHz, 50 kW) cover vast geographic areas, often several hundred to thousands of kilometers. LF signals offer distinct propagation advantages over higher-band transmissions such as GPS. Their long wavelengths (3–6 km) enable effective diffraction around obstacles like mountains and buildings. The ionosphere and ground act as a waveguide, eliminating the need for line-of-sight and allowing a single powerful station to cover extensive regions. Ground wave propagation minimizes ionospheric variability effects on transmission delay, and signals penetrate most building walls effectively. Robust and low-cost receivers, often priced at 20–30 USD/EUR, are widely used in radio clocks. These receivers typically comprise a tuned ferrite core antenna, a receiver IC (e.g., Atmel T4227, U4223B, MAS1016) for amplification and AM detection, and a microcontroller for decoding the time signal and phase-locking a local clock. Specific components for DCF77, MSF, and WWVB are readily available from vendors like HKW Elektronik and Ultralink.

Mooncalc shows the motion of the Moon and Moon phase for a particular day at a particular location. You can see the moon positions for moon rising, selected time and Moonset.

Make them simple then Make them work. The LAZY H antenna is a general type of antenna that is in the curtain array family. By placing two 1 wavelength dipoles in a plane that is at right angles to the direction of maximum radiation and keeping the proper in-phase current condition to each element, you can achieve a high gain bi-directional antenna.

Valon Technology designs and manufacturers low cost, reliable radio frequency products such as RF Synthesizer modules, RF Frequency Dividers and Phase Gain Detectors. Main markets are military/defense, test engineering, radio astronomy, research centers and universities

Manufacturer of amplifier for small magnetic and electric receiving wideband antennas, and variable delay line kit for active antenna phased arrays

DC filters from radius power are specifically optimized for applications with DC supply like e.g. photovoltaic inverters. Radius Power provides total power solutions, EMI filters solutions from design to manufacturing, Three Phase, Single Phase, Power Line, IEC inlet, Power entry modules Filters.

This resource provides a historical analysis of amateur radio call sign assignment policies in the United States, detailing regulatory shifts from the Department of Commerce to the Federal Radio Commission (FRC) and subsequently the Federal Communications Commission (FCC). It documents the evolution of call sign issuance, from early reissuance practices in the 1920s to the implementation of the Group Call Sign Assignment System on March 24, 1978. This system categorized call signs (e.g., 1x2, 2x1, 1x3, 2x3 formats) into groups A, B, C, and D, correlating with license classes such as Extra, Advanced, General, and Novice, and specifying prefixes for contiguous U.S. and territorial areas (e.g., _AH_, _KP_, _KL_). The document further details the legislative process leading to the modern Vanity Call Sign program, initiated by a petition in June 1990 and formalized by the Omnibus Budget Reconciliation Act of August 10, 1993. It outlines the FCC's adoption of final rules on December 23, 1994, and the subsequent fee structure, with the first vanity call sign issued on May 31, 1996, at a cost of **$30.00** for a ten-year term. The ARRL's proposed "starting gates" implementation strategy is also described, which phased in eligibility for vanity call signs based on license class and prior holder status. DXZone Focus: Historical Document | Regulatory Analysis | Call Sign Formats | Fee Structure

Explores the re-establishment of SDRGadgets as an online shop, focusing on accessories for Software Defined Radio enthusiasts. The proprietor details the process of rebuilding the website and restocking products after a hiatus, emphasizing a commitment to affordability and user experience in the SDR hobby. The site aims to offer items that enhance SDR operation, such as VFO controllers, without significant financial outlay. Anticipates a refreshed product line featuring a "sleeker and more technical look and feel," leveraging new manufacturing technologies. The owner expresses enthusiasm for showcasing these redesigned items and expanding the inventory beyond initial offerings, inviting customer suggestions to tailor product development. Welcomes both returning customers and new visitors, acknowledging the current limited product availability during the rebuilding phase. The site promises worldwide postage and encourages interaction for product ideas, aiming to foster a community around practical, budget-friendly SDR solutions.

The DIY 137 MHz WX SAT V-dipole antenna project details the construction of a specialized antenna for receiving weather satellite transmissions. It provides specific dimensions for the dipole elements, designed for optimal reception around the 137 MHz band, which is commonly used by NOAA and Meteor weather satellites. The resource outlines the materials required, such as aluminum tubing for elements and PVC for the support structure, along with the necessary coaxial cable and connectors. The article presents a clear, step-by-step assembly process, including how to form the V-shape and connect the feedline. It emphasizes practical considerations for mounting and weatherproofing the antenna for outdoor deployment. The design focuses on simplicity and effectiveness for amateur radio operators interested in satellite imagery. Key aspects include the precise angle of the V-dipole and the lengths of the radiating elements, which are critical for achieving the desired circular polarization response for satellite signals. The resource includes photographic documentation of the construction phases and the final mounted antenna.

A review of the 30 meter MonoGap Antenna. This review covers from the unboxing go the Gap product, the assembly of the elements, the test and tuning phase and a performance report during the years

Clarifies the intricate process of calibrating the _Elecraft K2_ dial, addressing common user challenges and lively discussions on the Elecraft reflector. Wilhelm, W3FPR, dissects the K2's PLL synthesizer design, chosen for its low phase noise, kit-friendly duplication, and cost-effective components. The resource emphasizes the critical role of the 4000.000 kHz reference oscillator's accuracy during CAL PLL, CAL FIL, and CAL FCTR functions, noting its dependence on temperature and crystal stability for optimal performance. Explaining the K2's frequency display, the document reveals it relies on microprocessor-driven look-up tables generated by CAL PLL for VFO values and CAL FIL for BFO values. In SSB and RTTY, these combine, while CW and CWr modes also factor in the sidetone pitch. The author details inherent limitations, such as the 10 Hz increment resolution of the dial and varying PLL step sizes—from 3 Hz on 160 meters to 10 Hz on 10 meters. BFO increments range from 20 to 35 Hz, collectively limiting practical dial accuracy to within **20 Hz** with diligent effort, or **30 Hz** for a slightly less demanding task. The guide outlines a four-step calibration procedure: setting the reference oscillator, running CAL PLL, running CAL FIL, and setting all BFOs. It highlights the _N6KR Method_ as a particularly easy and accurate approach, requiring only the K2 and a known frequency source like WWV for zero-beating, eliminating the need for external test equipment.

Enables Android users to operate various _miniVNA_ antenna analyzers via Bluetooth, USB, or Wi-Fi, providing a portable solution for RF measurements. The application supports full control over data acquisition, offering features like custom frequency range selection from 1 KHz to the VNA's full range, and automatic screen adaptation for diverse Android device resolutions. It facilitates intuitive, wizard-based calibration for both reflection and transmission modes, saving calibration data for different VNA types (Standard, Pro, Pro with Extender) to avoid repeated procedures. The software displays critical parameters such as SWR, |Z|, Return Loss, Phase, Rs, and |Xs| on 2-axis graphs or Smith charts, with multi-touch gestures for zoom and frequency shift. It includes a frequency generator mode with independent channels and attenuator control for the miniVNA Pro, along with a sweeper function. The cable data mode automatically calculates phase and loss, measures cable length from less than 1 meter to hundreds of meters, and includes a table of common coax cable velocity factors. An experimental X-tal mode measures resonance frequency, Rs, and Q. Data export options include CSV, ZPLOT, and S1P formats, with CSV import capability. The application also features an SM6ENG Audio mode for SWR tuning without visual reference and provides a miniVNA battery voltage indicator. It supports a wide frequency range, with the miniVNA Extender extending coverage up to **1500 MHz**. The application is compatible with Android version 2.2 and later, tested on devices like the _Galaxy TAB 7.7 P6800_.

A home made project to reduce noises from lower bands, an X-Phase QRM Eliminator project that can help you a lot

The Meteor-M N2 is a polar orbiting Russian weather satellite that was launched on July 8, 2014. Its main missions are weather forecasting, climate change monitoring, sea water monitoring/forecasting and space weather analysis/prediction. Meteor-M N2 transmits images using the digital LRPT protocol at around 137.1 MHz with can be received with an RTL-SDR.

I have RFI, now what– Locating it. This article is the first of a three parts article, that covers the problem of locating the RFI source. Author make use of an SDR receiver to locate RFI emissions. Ai interesting RFI location process diagrams helps on following the various phases, permitting the discovery of almost 75% of the RFI issues.

This is a vertically polarized Broadside and Collinear Array each Loop is a vertically polarized Broadside Array both the right and the left side of the Loop is a bent 1/2 wave dipole working 180 degrees out of phase with the other one and that gives you 4.15dbi of gain

This stacking offers a well known simple phasing technique. All elements can be fed in parallel by open wires provided that they are fed in phase. This can be achieved by twisting the open wire phasing-lines at 180 degrees.

This article details the design and construction of a homebrew two-element loop antenna array for HF reception. The DIY receiving antenna system consists of two 30-inch diamond-shaped loops spaced 20 feet apart, offering superior directivity compared to traditional vertical arrays. The design features broadband operation from 160m to 20m bands, requiring only phase-delay adjustments via feedline lengths. This home-built antenna system achieves 9dB RDF (Receiving Directivity Factor) performance comparable to a 300-foot Beverage antenna, while requiring minimal space and no ground radials, making it ideal for suburban installations and low-band reception.

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.

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

Amateur radio SDR Receiver and Transceiver manufacturer , makers of the Silphase R1 an innovative HF receiver with high performance real-time spectrum scope.

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.

Amateur radio enthusiast Jean-Paul Suijs discusses combating manmade noise (QRM) in radio signals using AI. Detailing experiments with phase-shifting techniques and the self-learning nature of AI, he explores AI-based audio processing apps for real-time noise cancellation during radio contests, demonstrating results on both medium wave and shortwave bands.

This article describes the phases for the construction of a Yagi antenna. The calculations of the parameters are made using 4NEC2 software. This type of antenna is used for transmissions and receptions of electromagnetic waves. The project shown here refers to the frequency of 433.92 MHz.

Constructing an effective antenna support system often involves safely elevating wire antennas into trees or over obstacles. This resource details the build process for the WT8WV "Colossus" air cannon antenna launcher, a pneumatic device designed to project a pilot line over elevated structures. It specifies the use of readily available PVC pipe components and standard hardware, outlining the exact materials required and providing step-by-step assembly instructions for a robust, low-cost solution. The article presents a practical alternative to traditional methods like slingshots, emphasizing the launcher's utility for Field Day operations and general antenna deployment. It includes a comprehensive list of parts, such as 2-inch and 1-inch PVC pipe, various fittings, a sprinkler valve, and a bicycle pump valve, detailing their integration into the final assembly. The total cost for materials is estimated at around $40 per unit, making it an accessible project for many radio amateurs. Crucially, the guide incorporates essential safety precautions for operating a pneumatic launcher, covering aspects like pressure management and projectile selection. It also features multiple photographs illustrating the construction phases and the completed device, offering visual clarity to aid builders in replicating the design.

TFilter is a free online tool for designing linear phase, optimal, equiripple finite impulse response (FIR) digital filters. It utilizes the Parks-McClellan algorithm implemented in JavaScript. Users can specify the sampling frequency, desired number of taps, passbands, and stopbands to generate a filter. An example configuration is provided for easy testing.