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This tutorial provides background information on the decibel and instructions for performing calculations involving decibels. This tutorial combines information from several authors, including Bob DeVarney, W1ICW; Walter Bahnzaf, WB1ANE; and Ward Silver, NOAX

SWODXA is comprised of active DX'ers and contesters with a deep passion for all aspects of Amateur Radi

Getting your Raspberry PI up and running your D-Star radio kit. This will work with DVAP / DVRPTR or DVmega

A linear regulated power supply 2A, 20 V designed mainly to get used to soldering and have something usefull as final result.

NFM (for Noise Figure Meter) is a software application to assist Noise Figure measurement. NFM implements the method of Agilent application notes AN 57-1 and AN 57-2 for noise figure measurement, but with the addition of an adjustable attenuator after the noise source and between the DUT and instrument.

Listing of North American Class 1, industrial,short line, tourist and transit lines. Includes a listing of all the frequencies sorted numerically.

Amateur radio blog from UK

PowerFilm, Inc. develops and manufactures thin, flexible solar modules for OEM, military and consumer needs.

Peninsula Amateur Radio Club - W4MT - Newport News, Virginia

West Essex Amateur Radio Club, Essex Fells, NJ

Can Home Solar Power and Ham Radio Coexist? It is possible, with minimal interference from the solar power system, provided you make some modifications.

Reducing and removing RFI Noise

Ham radio blog in English and Dutch. The radio adventures of PE4BAS.

A simplified explanation of decoding West German numbers messages transmissions without a computer.

NEScaf: A Switched Capacitive Audio Filter

The _Touch CPO_ circuit offers a unique method for Morse Code practice, eliminating the need for a physical key. It leverages the versatile IC555 timer, configured as an astable multivibrator, to generate an audio tone. Users can adjust the tone's frequency by manipulating a 100 K variable resistor connected between pins 7 and 6 of the IC555, providing flexibility in the practice experience. Volume control is achieved via a 10 K variable resistor, while a 1 K Ohms preset at pin 4 of the IC555 allows for fine-tuning the touch plate's sensitivity. The design connects the touch plate to the base of a BC147B transistor, a configuration noted for its flexibility regarding the length of wire between the transistor and the touch plate. The author's prototype successfully used a 9 cm wire with a 3 x 6 cm aluminum plate. This project also suggests an alternative application as a touch-operated doorbell, demonstrating the circuit's adaptability. The design emphasizes simplicity and ease of construction, making it accessible for hams interested in DIY electronics.

Nearly half of all reception problems are due to deficiencies or faults in the television receiver, the aerial lead or the aerial. This article will help you to check whether the problem you are having is due to one of these causes.

Martek Power designs and manufactures a wide of high performance power supplies for various industries. Power supplies AC-DC, DC-AC inverters, DC-DC, EMI Filters

In 1996 the NWARC was formed and is a non-profit society organized to deliver communication services during emergencies.

How-to decode and Display APRS Packets from WebSDR Audio using linux computer

Interesting article on how Marc Van Stralen, PA1HFO, took the Drake TR-7 Transceiver to the Next Level.

Experimental Stations Run by W1TAG WD2XES has been used to study LF antenna design, propagation and communication modes. Signals from WD2XES have been copied as far away as Russia.

A 12V powered, 4x15 Watt quad audio amplifier

23 cm PA with Mitsubishi RA18H1213G

Sent every Saturday, Amateur Radio Weekly is an email newsletter containing links to the most relevant news, projects, technology, and events happening in Ham Radio

North Carolina amateur is refuting a clean bill of health the FCC gave this summer to a BPL field trial system in the Raleigh area.

PV Solar Panels, Photovoltaic Panels, Solar Power

New Club Site For Maidstone YMCA ARS

Beacon website of WE4S, Grady Donaldson, located in McDonough, GA. EM73TM.

A collection of projects and equiment home made for 24 GHz operations

A tutorial on how to setup a receiver capable to decode SSTV signals with a small RaspberryPi version 2 and a RTL-SDR dongle. The author explains how to install the needed software to interface the RTL-SDR and a step by step guide to install the QSSTV software used to decode the signals.

Official web site for the ILLW event. Maintained by vk2ce.

G3CWI contest software reviews, compare NA SD TR CT and WriteLog

A Tower Project at WOIVJ. A pictorial story of the erection of a 40 foot, self-supporting, fold-over tower.

Demonstrates the construction of a high-power 6-meter (50 MHz) amplifier, specifically designed for demanding modes like EME, TEP, and multiskip Es. It details the use of a _GU-43B_ tetrode in a grounded-cathode configuration, emphasizing the need for stabilized grid voltage and input capacitance compensation. The resource provides a comprehensive schematic, power supply design, and practical considerations for component sourcing, particularly for high-voltage and high-current sections. The builder achieved an output power of **1250 watts** with an anode current of 0.65 amperes and 3200 volts anode voltage. The article also covers the physical construction within a modified P6-31 enclosure, outlining the internal layout for RF and power supply sections, and includes photos of the completed unit. It highlights critical safety precautions for working with high voltages and reactive currents up to **20 Amperes** in the P-network.

Propagation forecast for the southern African region by SANSA

Electronic components and parts supplier: semiconductors, capacitors, diodes, transistors, resistors, and more since 2005

What is VSWR and why you should care, formal definition of VSWR and SeaSonde Measurements, formulas

Testing a linear regulated power supply using headlight bulbs for loading.

My view on the world of AMATEUR RADIO- "Rambling on" so to speak

radio.McDougallsHome.net The Web site and Blog of Amateur Radio Station K7JM. Homebrew, Construction, Operating, and Discussion

Sponsored by the Oklahoma DX Association

G8YMM Amateur radio web site with interest on ATV

Accurate meteorological data is crucial for optimizing antenna performance, predicting propagation, and ensuring safe tower work. This resource provides a curated inventory of weather stations, including models like the _AcuRite Atlas_ with lightning detection and the _Ambient Weather WS-2902_ WiFi Smart Weather Station, which offer real-time data on environmental factors. The product listings detail specific features such as direct-to-Wi-Fi connectivity, rainfall tracking, and temperature insights, enabling informed decision-making for various amateur radio operations. The platform categorizes products by application, featuring weather stations tailored for home and backyard use, as well as more robust systems for farm and agriculture, which can be critical for field day operations or remote station monitoring. It also highlights _Made in USA_ options, emphasizing local manufacturing and support. Beyond weather instruments, the site also presents related surveillance technology, such as the _Waggle solar CCTV camera_, designed for outdoor reliability with an IP65 weatherproof rating. This integration allows for comprehensive monitoring of remote ham radio shacks or antenna sites, combining environmental data with visual oversight.

Showcasing innovative RF solutions, Hofi Hochfrequenztechnik manufactures high-quality _antennas_ and RF switches. Their products, including the **versatower** and **fritzel** brands, cater to both casual operators and serious DXers. With a commitment to performance, Hofi's offerings enable operators to achieve optimal signal gain and reliability in various conditions. The company's expertise in antenna design ensures that users can effectively communicate across _HF_ bands, enhancing their overall operating experience. Whether setting up a new station or upgrading existing equipment, Hofi provides essential tools for successful ham radio operations.

Monitoring extremely weak signals in the QRSS (Very Slow Morse) mode requires specialized receiving and processing capabilities to extract information below the typical noise floor. This project provides a software solution, _QrssPiG_, designed to run on a Raspberry Pi, enabling it to function as a dedicated QRSS grabber. It interfaces with various Software Defined Radio (SDR) devices, including the popular _rtl-sdr_ dongles and _HackRF_ units, to acquire raw I/Q data streams. The software then performs the necessary signal processing to visualize and decode these faint, long-duration CW transmissions, often operating with milliwatts of power. The system leverages the computational power of the Raspberry Pi for real-time signal analysis, allowing hams to participate in QRSS experiments and monitor distant beacons. It supports different SDR hardware, offering flexibility in setup and deployment for home stations or remote monitoring sites. The project includes detailed instructions for installation and configuration, making it accessible for those familiar with Linux environments. This grabber is particularly useful for tracking propagation on the LF and HF bands where QRSS activity is common, providing a visual representation of signal presence over extended periods.

To gain Tonga DXpedition Award it is necessary to have QSL confirmed contacts with two amateur radio expeditions from Tonga (A35), on two bands, with two diffrent modes. Available also to SWLs

KiwiSDR Software-defined receiver at Bjargtangar Iceland covering HF Bands

A 3CX1500/A7 8877 144mhz W6PO amplifier, that running a little over 4kv on the plate, this Amp will do over 2kw out.

CE9/VE3LYC and CE9/PA3EXX Wollaston and Diego Ramirez Islands 2011