Search results

Tune in live to the Grants Pass DPS police radio and Josephine County Sheriff's Office radio feeds.

The project outlines the process for constructing a low-power FM broadcast transmitter using a Raspberry Pi Zero, a simple wire antenna, and battery power. It details the software installation steps for PiFM and MPG123, essential for generating and transmitting audio. The resource provides instructions for configuring the Raspberry Pi to broadcast FM signals, including command-line operations for initiating transmission and playing audio files. It specifically focuses on the Raspberry Pi Zero's capabilities for this application, highlighting its cost-effectiveness and minimal hardware requirements. The content presents a practical, hands-on approach to creating a basic FM transmitter, suitable for short-range, experimental broadcasting. It includes guidance on testing the FM output and ensuring proper operation of the software components. The project emphasizes the use of readily available components and open-source software to achieve functional RF output.

Morse Tutor is a DOS based program written in C++. It can be used to practice morse code. Various options are available. Morse tutor with Complete Source Code and Binary is available for Download (32KB).

A well documented article on a small magnetic loop antenna for the 40 meters band

Some antenna manufacturers place baluns at the incorrect location in LPDA arrays, or tell you to route the cable incorrectly. This can cause substantial RFI and all sorts of weird problems like RF into house wiring.

Schematic Manual of the 3 element Yagi antenna by ECO antenne

CB radios, mobile phones and scanners

A basic article on end-fed antennas by KB6NU

Home page of the Dallas Amateur Radio Club, located in Dallas, Texas. The DARC is one of the oldest clubs in the country, founded in 1914.

This article describes how to use a phone line as a shortwave receiving antenna, but be carefull telephone lines present a potential shock hazard, use at your own risk

Satellite Tracking and Orbit Propagation, Reports and Mission Planning Products, Pass Scheduling and Orbit Event Analysis, Dynamic Communications Link Modeling, 3-D Visualization of Complex Scenarios User Defined Regions and Contours, Constellation and Formation Flying Support, Global Positioning System Coverage

Preamp & Power Amp By Alkberto, I0XGR

The no counterpoise antenna

CW decoder project that automatically adapts itself to the CW rate and may be employed for learning purpose substituting the traditional tone generator and offering the capability of displaying the keyed code.

2 element reversible verticals, small footprint, big results.

The U.S. Amateur Radio Callsign Lookup service, hosted by the University of Arkansas at Little Rock (UALR), offers a direct interface for querying the FCC's amateur radio license database. This resource is specifically designed for rapid retrieval of licensee information, including callsign, name, address, license class, and expiration date, all critical data points for QSLing and contact verification. The underlying database is refreshed daily, ensuring that the presented information reflects the most current FCC licensing records available. This service distinguishes itself by its direct reliance on official FCC data, processed and maintained by a university institution, which lends a degree of authoritative accuracy to its lookups. Users can input a specific callsign to instantly access detailed license particulars, facilitating efficient station identification and record-keeping for DXers and contesters alike. The daily update cycle minimizes discrepancies often found in less frequently synchronized callbook services. The UALR callsign lookup functions as a straightforward, no-frills utility, prioritizing data integrity and accessibility for the amateur radio community. Its operational simplicity and consistent data refresh schedule make it a reliable reference for verifying U.S. amateur radio licenses.

A small portable antenna tuner for HF and VHF bands by ON6MU

If your local repeater has got you singing the PL tone blues, then read on. For less than $10, an inexpensive PL tone generator can be constructed that will bring new life into that old non-PL rig.

Fractal Antennas are a new generation of multiband antennas for wireless communications. Based on a new design concept, fractal technology.

SWIFT WX Version 2.0 combines a powerful GIS mapping engine with real-time weather maps and storm tracking data making it the most comprehensive storm tracking application available.

Understanding high-frequency (HF) skywave propagation is crucial for amateur radio operators seeking to optimize long-distance communications. This resource details the fundamental principles of HF radio propagation, including the properties of electromagnetic waves, the characteristics of various HF bands, and distinct propagation modes such as skywave, ground wave, and line-of-sight. It places significant emphasis on the ionosphere's pivotal role in refracting HF waves, explaining how solar activity directly influences ionospheric conditions and, consequently, propagation paths. The resource integrates real-time monitoring capabilities, featuring dynamic charts and data from DX clusters, WSPRnet, and the Reverse Beacon Network, which allow users to track current band activity and propagation conditions globally. It also delves into advanced topics like Near Vertical Incidence Skywave (NVIS) and gray line propagation, providing insights into ionosonde data and various propagation prediction models. The site presents a detailed analysis of solar-terrestrial interactions, geomagnetic indices, and space weather phenomena, illustrating their direct impact on HF communication reliability. Practical tools and applications are highlighted, including real-time QSO planners, online Maximum Usable Frequency (MUF) maps, and alerts for solar flares or geomagnetic storms. The guide systematically breaks down complex concepts into accessible chapters, offering a structured approach to learning about ionospheric regions, diurnal and seasonal effects, and the interpretation of propagation indicators like foF2, MUF, and Lowest Usable Frequency (LUF). This makes it a robust reference for hams aiming to deepen their technical understanding and improve operational effectiveness.

An easy to build multiband trapped dipole that can work well on short low bands for skip contacts

Onine Log for 9J2T DX Pedition

A different approach can help you optimize attic-bound aerial by W6HPH

Compact HF antennas for home and mobile use, compact HF maritime antennas, manufactured by multi-band antennas

Long Waves, Short Antennas, designing antennas for MF and LF communications

Proppy: Online HF propagation predictions using the ITU Recommendation P.533-13 Propagation Prediction Application.

Portable magnetic loop antennas - G4TPH Mag-loop antennas Reviewed in PW and RadCOM, Both QRP and QRO, Portable. The only Magloop on the market that is fully portable

Multiband and monoband HF Vertical antennas and rotatable dipoles manufacturer based in Texas USA

Demonstrates the construction of two distinct wideband RF preamplifiers, detailing their component requirements and performance characteristics. The first design leverages monolithic microwave integrated circuits (MMICs) such as the MAR-6, MAR-8, or PGA103, offering a broad frequency response from DC to 2 GHz with a gain of 22.5 dB at 100 MHz and a noise figure typically below 3 dB. This MMIC-based amplifier incorporates protection against power supply transients and features a 50 Ohm input/output impedance, operating from an 8-20 volt supply with low current drain. The second preamplifier design utilizes a BSX-20 transistor, providing amplification across the 14 MHz to 550 MHz range. This simpler, more economical build achieves an average gain of 12 dB at 145 MHz and a noise figure of approximately 1.1 dB. It operates from a 7-15 volt battery supply with a current draw of 6 mA. Both projects emphasize critical construction techniques, such as maintaining short RF connections, ensuring 50 Ohm impedance paths, and mounting the circuit within a shielded enclosure to optimize performance and minimize noise. The resource also discusses phantom power options for antenna-mounted preamplifiers and precautions for use with transceivers, including output protection diodes and static bleeders.

GitHub reposotory of QradioPredict, a radio propagation prediction tool for VHF-UHF, based on the Irregular Terrain Model, also known as Longley-Rice. Can be used as a repeater site planing tool. Has an internal APRS client which can be used to display stations as a landmark.

The Swedish EH Antenna Group

Terrasat Communications specializes in advanced RF technology for satellite communication, focusing on _Intelligent Block Up Converters_ (IBUCs) and Solid State Power Amplifiers (SSPAs). These products are engineered to enhance satellite link performance, offering features like extended frequency ranges and high power efficiency. The IBUC series, for instance, integrates a BUC with an SSPA, enabling operators to install, configure, and monitor units for both commercial and military satellite applications, ensuring reliable, high-performance connectivity worldwide. The company's offerings support various satellite bands, including C, X, Ku, and Ka, providing solutions for diverse operational requirements. Their technology is designed for robust field performance, with products like the _IBUC2_ and _IBUCG_ models demonstrating the integration of advanced diagnostics and control capabilities, which are crucial for maintaining optimal signal integrity in demanding environments. Terrasat's focus on _SSPA_ technology underscores a commitment to power efficiency and compact design.

This is from a posting on the BARK PBBS Keith, WB2VUO

Constructing a functional spectrum analyzer for the 0-100 MHz range presents a significant challenge for radio amateurs, often requiring specialized components and careful calibration. This project details a homebrew spectrum analyzer design utilizing common integrated circuits like the _SA605D_ FM receiver IC and _MAR-6_ MMIC amplifiers, aiming for a cost-effective solution. The design incorporates a low-pass filter, RF amplification, a voltage-controlled oscillator (VCO) for downconversion, and multiple IF stages at 150 MHz and 10.7 MHz, with a resolution bandwidth (RBW) of 15 kHz. Critical components such as the _SBL-1_ mixer and varicap diodes are specified, alongside instructions for winding inductors and tuning filters. The analyzer's performance is discussed in terms of input level limitations, specifically the 1dB-compression point and third-order intercept point, to ensure accurate measurements and prevent component damage. The _SA605D_'s logarithmic Received Signal Strength Indicator (RSSI) output serves as the detector, driving the Y-input of an oscilloscope, while a _TL084_ op-amp generates the sweep signal for the X-input. Potential enhancements include adding a step attenuator, improving front-end filtering, and implementing switchable IF filters for variable RBW, allowing for greater versatility in analyzing RF signals.

A simple beam antenna offering good performances on 3 bands by 9m2mso

How to easy connect two Pc together with a Ethernet Lan

High speed silicn diodes work well as RF switches. This article describes how to use diodes for selecting two or more filters ARRL QST article by W1FB

Over **10 million** antennas and flags have been sold worldwide by Firestik Antenna Company, a veteran-owned manufacturer specializing in both CB and amateur radio communication products. Their offerings include a range of antennas, mounting accessories, and coaxial cables, designed for various mobile and fixed applications. The company provides technical support and maintains a network of dealers for product availability. Firestik products are known for their fiberglass construction, which is evident in their _Firestik_ and _Firefly_ antenna lines. The company also produces unique items like the "342 mile per hour Firestik flag," highlighting their diverse manufacturing capabilities beyond just radio antennas. They emphasize their commitment to quality and customer service, including direct technical assistance. The company is located in Tempe, Arizona, and operates under the registered trademark of _Pal International Corporation_. They actively protect their brand, including variations like Firestick and Firestix, ensuring proper representation of their products in the market.

An introduction to antennad including a DIY assembly instruction for a A Ground Plane Antenna for NOAA Weather Stations

Live Walton County Sheriff, Fire, and EMS Radio

Astron corporation power supplies and accesories

Land communications and marine antennas

The Classic Multiband Dipole Antenna QST article. The open-wire feed line dipole antenna is easy to install and offers surprising performance on several bands. You can install it in almost any configuration; it does not have to be strung in the traditional horizontal flat top

This is a 200 Watt PEP step up transformer for end fed full and half wave antennas without radials, designed as a 200 Watt PEP

This database contains data on thousands of tubes

Mclennan County Sheriff and Fire, Waco and Area Police and Fire, listen to live police audio feed

WAS Map, worked all States by ARRL

Outbacker mobile and portable antenna systems are slim line, highly efficient, single whip multi bond antennas for vehicular and limited space portable applications.