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A Shielded Low Frequency Loop Antenna, allows Simultaneous Transmission and Reception at the Same Site.

Stand Alone Software Defined Radio, direct sampling receiver from 30 kHz to 1700.00MHz continuous frequency range, LAN interface for remote access

Northern New Jersey, New York City/Long Island and Westchester County frequency coordination

Amplitude Modulation (AM) is essentially a mixing process where the audio modulating signal is mixed with the radio frequency carrier

UK frequency list provide reference table to lister to Police scanner channels UHF VHF, Amateur Repeaters, Ambulance CB Radio CoastGuard Rescue, marine VHF, Military and more.

Tektronix Frequency Counters pack the functionality of a frequency counter, meter and timer into one instrument.

Unlike older radios, the 706 uses only one crystal oscillator (called the Master Oscillator). All other frequencies in the radio (L.O., 3-4 I.F. stages, VFO, and CW-offset) are computer-derived from the Master Oscillator. This makes it relatively simple to frequency-align the radio, so that it agrees with the Frequency Display in all modes.

A basic YAGI UDA online antenna calculator, accept as input frequency, number of elements, diameter of parasitic element and boom diameter. This online calculator will generate a basic design data including each element length and spacing.

Amateur radio repeaters, often designated by an "R" number like _R6_ or _R5_, serve as crucial infrastructure for extending VHF/UHF communications range. This resource from Essex Ham explains the fundamental concept of a repeater, detailing how it receives on one frequency and simultaneously retransmits on another, typically with a 600 kHz offset for 2-meter repeaters. Understanding the input and output frequencies, along with the required CTCSS tone, is essential for successful access, ensuring your signal is processed and relayed across a wider service area. The article clarifies the importance of using the correct _CTCSS_ (Continuous Tone-Coded Squelch System) tone, often referred to as a sub-audible tone, to activate a specific repeater. It also touches upon the concept of _simplex_ operation versus repeater use, highlighting the benefits of repeaters for mobile and handheld transceivers. Proper operating procedures, such as listening before transmitting and keeping transmissions concise, are emphasized to maintain good amateur practice on shared repeater assets.

Determining the characteristic impedance (Z) of an unknown coaxial cable, a common challenge for many radio amateurs, can be resolved with a straightforward method. The impedance of a coaxial cable is derived from its inductance and capacitance, and importantly, these values are independent of the cable's length or the operating frequency. This means that measuring a random length of cable, such as 20 meters, provides sufficient data for calculation. The core of this technique involves an LC-meter to obtain the inductance (L) in microHenries (uH) and capacitance (C) in microFarads (uF). The impedance is then calculated using the formula Z = L/C. For instance, a measurement yielding L=1.2uH and C=450pF (0.00045 uF) results in an impedance of 51.6 Ohms, closely matching **RG-58** specifications. Similarly, a TV coaxial cable with L=1.8uH and C=320pF (0.00032 uF) calculates to 75 Ohms. While the accuracy of this method, depending on the LC-meter's tolerance, is approximately 10%, it proves sufficiently precise for practical determination of unknown coaxial cable impedance, as noted by Makis, SV1BSX, who credits Cliff, K7RR, for the formula's dissemination.

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.

An online reference table with Satellite information including current status, uplink and downlink frequencies.

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_.

PRO-LINK specializes in the manufacturing and distribution of high-quality cabling solutions, including a wide array of fiber optic cables and various coaxial cable types. Their product line encompasses 50-ohm and 75-ohm coaxial cables, essential for diverse RF applications, alongside specialized RF cables and 10Base-T networking cables. The company also provides a selection of connectors and custom cable harnesses, catering to specific installation requirements. Since 1988, PRO-LINK has offered a 5-year warranty on its products, underscoring a commitment to durability and performance. The product catalog details specifications for different cable constructions, such as _RG-58_, _RG-213_, and _LMR-400_ equivalents, which are commonly used in amateur radio installations for antenna feedlines and inter-component connections. Their offerings support both commercial and amateur radio operators seeking reliable signal transmission. The company's focus on robust cable and connector solutions addresses the critical need for low-loss transmission lines in radio communication systems, ensuring signal integrity across various frequency bands.

Frequency agile 80 metre CW QRP transmitter. Ceramic resonators vary in the frequency shift obtainable. The one in the prototype of this article gave 3.525 to 3.558 MHz coverage.

Antennas custom made to your frequency of choice

Microwaves101 provides an extensive repository of information covering fundamental principles of microwave design, targeting engineers and radio amateurs interested in the higher frequency spectrum. The site features a detailed _encyclopedia_ of microwave terms and concepts, alongside practical design considerations for various components and systems. It serves as a foundational reference for understanding RF propagation, transmission lines, and active/passive microwave circuits. The resource includes numerous calculators for impedance matching, filter design, and other critical RF parameters, facilitating hands-on project development. Discussions on **10 GHz** equipment and **24 GHz** projects highlight practical amateur radio applications, extending to operations up to 134 GHz. Content spans from basic theory to advanced topics like MMIC design and antenna characteristics, supporting both educational and practical endeavors in microwave technology.

Design and manufacture antennas for mobile devices, wireless data including WiMAX, WiFi, and WISP (Wireless Internet), two-way radio and RFID (Radio Frequency Identification).

With BktDxCluster you can connect to all DX Cluster with DXSpider Protocol and telnet connection, filter the spots, send new spots, send commands to the cluster, set the radio to the frequency of the spot through BktRemote. Adroid App

a subcommittee of the Amateur Radio Council of Arizona

DOMINO DF is a sensitive mode which, due to its incremental frequency keying and thanks to its interleaved multiple tones sets, is easy to tune and is few sensitive to interference and ionospheric effects. Domino faeture a great signal to noise ratio.

Upper New York Repeater Council, Inc, support the frequency coordination needs of the Amateur Radio repeaters operating in its area

Frequency coordinations on BC Canada

Before the advent of satellite communication, maritime communication adhered to an international protocol requiring ships and coastal stations to observe silent periods twice an hour, reserved specifically for emergencies. These silent periods were marked by red sectors on the 500 kHz frequency and green sectors on the 2182 kHz frequency. The 4-second red bars facilitated the manual transmission of the SOLAS distress signal.

The Precision VXO (PVXO) and its matching Crystal Test Fixture (CTF) were created to provide a low cost means of evaluating the characteristics of crystals and a means of measuring their series resonant frequency.

Details Amphenol Connex's product range, focusing on RF connectors, adapters, and cable assemblies. The company produces common radio frequency interfaces such as _BNC_, _SMA_, and _TNC_ connectors, alongside numerous other specialized designs. These components are critical for establishing reliable signal paths in amateur radio stations, ensuring proper impedance matching and minimal signal loss across various frequency bands. The manufacturing process emphasizes precision engineering to meet the demanding specifications of RF applications, from HF to microwave frequencies. Product lines support diverse coaxial cable types, facilitating custom cable assembly for specific station configurations. The extensive catalog provides solutions for both fixed station installations and portable operations, addressing the needs of contesters, DXers, and general amateur radio operators.

The Straits Area Amateur Radio Club (SAARC) operates a 146.68 MHz (-) repeater with a PL tone of 110.9, serving Northern Michigan for emergency communications and community support. A temporary cross-band repeater on 445.875 MHz is also available during specific hours, enhancing local coverage. The club actively supports disaster services through its repeater infrastructure and coordinates local community events. SAARC provides resources for prospective hams, including information on licensing classes and testing sessions, and promotes amateur radio education. Members and interested individuals can join the club's Groups.IO group for updates and participate in the Bill DeMay _K8GUG_ Memorial Net, held weekly on Monday evenings at 8:00 PM on the primary repeater frequency.

On the field comparison among C-Pole antenna, an EFHW vertical antenna and an Inverter V dipole antenna. Test is done using two identical WSPRLite beacons that transmit with 200mW on the WSPR frequency and analyzing spotted results.

recognized Amateur Radio Frequency Coordinating entity for the State of Arkansas.

Illustrates the fundamental principles of radio repeaters, detailing their role in extending communication range beyond line-of-sight limitations. It begins by defining _simplex communication_ as a direct radio-to-radio link, effective only when no obstructions impede the signal path. The resource then introduces the concept of a repeater (or base station) strategically positioned on elevated terrain, such as a mountain, to overcome geographical barriers. The article clarifies the repeater's operational mechanism: it receives a signal on one frequency and simultaneously re-transmits it on a different frequency, enabling users on opposite sides of an obstruction to communicate. This _duplex operation_ is likened to satellite communication for VHF propagation, but with a fixed terrestrial station. Specific examples of signal paths are provided, showing how a handheld radio transmits up to the repeater, which then relays the message down to another user, effectively bypassing obstacles like hills or large buildings.

Time Mapper UHD is a versatile mapping and time visualization program offering multi-satellite viewing with frequency display and unique country-pairs for PskReporter data. It features live feeds from logging programs and can plot ADIF files. Ideal for schools, offices, or amateur radio stations, it provides customizable 4K or HD world clock displays with over 60 map layers, including ham radio zones and natural features. The program supports various time functions and can import logs for detailed analysis. It runs on Windows 10 or 11 and offers a 30-day free trial.

TelExpress provides a wide array of RF and data connectivity products, including various coaxial cables like LMR-series equivalents, fiber optic cables, and Ethernet solutions. Their inventory supports diverse amateur radio and telecommunications requirements, from antenna feedlines to network infrastructure. The site emphasizes bulk cable availability and custom assembly services, catering to both individual hams and larger installations. Key offerings include _low-loss coax_ for HF and VHF/UHF applications, along with a comprehensive selection of RF connectors. They also supply patch panels, Ethernet cables (Cat5e/Cat6), and general wireless and telecom hardware. Customers can find components for building robust station infrastructure, ensuring signal integrity across various frequency bands. The platform facilitates procurement of essential parts for new builds or upgrades, supporting reliable RF system performance.

Presents Wayne Kerr Electronics, a manufacturer specializing in precision component measurement products. The company offers a range of LCR meters, impedance analyzers, and transformer test systems designed for various applications in electronics manufacturing and research. Specific product lines include the 3260B Precision Magnetics Analyzer, which measures inductance, capacitance, and resistance with high accuracy, and the 6500B series of LCR meters, capable of testing components across a broad frequency range up to 120 MHz. The 3255B and 3265B series provide solutions for transformer and inductor testing, including turns ratio, leakage inductance, and inter-winding capacitance measurements. These instruments are utilized in quality control, component characterization, and production line testing, ensuring performance and reliability in electronic circuits. Wayne Kerr's offerings support engineers and technicians in verifying component specifications.

The MiniTioune receiver project, developed by Jean-Pierre F6DZP, consists of the home constructed MiniTiouner hardware which interfaces via a standard USB 2.0 port to a Windows PC running the MiniTioune software. It can be used to receive satellite broadcasts transmissions making it ideal for use on Q-oscar 100 Es hail-2 without any external frequency converters.

NanoVNA based on edy555, use the odd harmonic extension of si5351 to support the measurement frequency up to 900MHz. GitHub repository.

There are several ways to reduce the length of a dipole and still use it as an effective antenna. Remember it is the electrical length that determines resonance. The physical length can be considerably less than a half wave length on your desired frequency as determined by 468/f MHz.

Article about Standing-wave ratio (SWR) defined as a mathematical expression of the non-uniformity of an electromagnetic field on a transmission line. SWR is the ratio of the maximum radio-frequency (RF) voltage to the minimum RF voltage along the line.

Passive Bandpass Filter online calculator and filter formulas. Active Inverting Op Amp Bandpass Filters, Active Noninverting Op Amp Bandpass Filter, just enter the Low ir High Cutoff Frequency

A spectrum analyzer is always an usefull amateur radio test equipment that should be present in a radio shack. Hams can use it for testing frequency response of filters, amplifiers, and other two-port RF devices. This article illustrate a tracking generator compatible with any spectrum analyzer in the Tektronix 490- and 2750-series lineups

This transmitter covers the 160, 80, 40 and 20 metre bands and provides both SSB and properly generated CW. The CW side of this transmitter is not compromised and produces excellent CW. On SSB the audio has been tailored to provide a rising response to 3 KHz, with a sharp drop above that frequency. There is RF speech clipping to both provide more "punch" and to limit the peak output.

The Waterway Net, sponsored by the Waterway Radio and Cruising Club, is dedicated to enhancing amateur radio communications for recreational boaters. Meeting daily at 0745 ET on 7.268 MHz LSB, the net focuses on safety and weather updates, providing a vital link for live-aboards and cruising boats to stay connected with families and friends. Position Reports and Float Plans are essential components that ensure safety for offshore passage makers. Established in the early sixties, the Waterway Net is one of the longest-running nets in amateur radio history. Open to all amateur radio operators with a General class license or higher, it encourages participation without requiring WRCC membership. Newcomers are advised to listen initially to understand net procedures before checking in. In emergencies, FCC regulations allow anyone, licensed or not, to use any frequency to call for help, with the 20-meter frequency of 14.300 MHz available for emergency assistance approximately eighteen hours a day.

Online HF Communication prediction system provided by the Australian Governament Buerau of Metereology allow to predict usable frequency rage for radiocommunications between two stations allowing to specify frequency and date range. This tool allow calculation with different methods and algorithms

open source hardware for software-defined radio. HackRF One is an open source hardware platform that can be used as a USB peripheral or programmed for stand-alone operation. 1 MHz to 6 GHz operating frequency

The amateur radio listener for when you're not on the radio. Repeater-START, the offline repeater listing app for Windows, Linux, Raspberry Pi, Ubuntu, Librem Phone is available, Now with grid square display, topographical maps and frequency preferences

Operating an amateur radio station effectively requires reliable coaxial cable to minimize signal loss between the transceiver and antenna. SIVA Cavi, an Italian manufacturer, produces a range of coaxial cables, including specific 50 Ohm low-loss types suitable for amateur radio applications. Their product line features cables like **RG 58 SHF1**, **RG 213 SHF1**, and **RF 400 SHF1**, which are commonly deployed in HF and VHF/UHF setups. The company also offers specialized cables such as the **HF 214 UF Ultraflex**, a high-performance broadband low-loss 50 Ohm cable designed for flexibility and reduced attenuation across various amateur bands. These cables are engineered with solid or foam dielectric materials, impacting their electrical characteristics and suitability for different power levels and frequency ranges. For instance, foam dielectric cables often exhibit lower loss at higher frequencies, a critical factor for VHF/UHF operations. Beyond amateur radio, SIVA Cavi manufactures cables for digital video broadcast, offshore marine use, and fire detecting systems, demonstrating a broad engineering capability in coaxial cable technology.

This page offers an online antenna designer tool for Hams to calculate the dimensions needed to construct a coaxial collinear antenna for a specific frequency. It provides guidance on the required frequency input, coax velocity factor, and element measurements for optimal performance. The tool is recommended for experienced antenna builders due to its complexity and technical requirements. Users can input the frequency in MHz and the tool will generate the necessary dimensions based on the chosen parameters. The page emphasizes the importance of accurate measurements and connections for successful antenna construction.

This article shares the author's experience with building antennas. After putting a large magnetic loop project on hold, they decided to try a base-loaded vertical antenna. The author explains how they chose to design a new antenna from scratch, aiming for a frequency of 7 MHz. They describe the calculations needed to find the right coil inductance and how they used 3D-printed parts for the construction. The article wraps up with results from their initial tests, showing good communication on different bands and highlighting the success of their design.

All Satellites Frequency List Update. A complete list of satellite frequencies available in several formats, including info on Satellite Uplink and Downlink frequencies Beacon, operative Mode, Callsign and Weather sat functionality.

The video delves into the significance of interference reduction in ham radio setups by utilizing ferrite materials. It demonstrates the use of spectrum analyzers and tracking generators to showcase the performance of ferrite devices in minimizing noise levels. The analysis includes insights on resistance levels, attenuation factors, and the impact of using multiple ferrite clamps or rings to enhance noise reduction capabilities. Viewers gain a deeper understanding of ferrite composition, characteristic curves, and winding techniques for effective noise attenuation in different frequency ranges. Overall, the video serves as a comprehensive guide to optimizing interference reduction in radio environments through the strategic use of ferrite materials.

Just a simple signal generator based on ADF4351 module from fleebay allows you to generate one single frequency that can go up or down in 100Khz steps via two push buttons.