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Eham.net review of ICOM IC-2720H

Receiver tests of some transceivers and receivers including FT-1000, FT-2000, IC-751, IC-756 IC-7800 and TS-870

Maker of optical spectrum analyzers, digital oscilloscope, digital power meters and more test equipmente related products

Detailed pictures and description of antenna tower setup

This circuit stores a single morse code message as bits in an EPROM chip, the message is sent to a relay which can key a CW transmitter.

Amateur Radio operation and weak signal detection pages by AF9Y

A comeplete home made 600W LDMOS RF power amplifier. Settings can be made on a 7-inch touch screen, and on this screen you can see a lot of useful information during operation, such as output power, temperature, SWR, and so on. The power amplifier includes 2 MRF300 LDMOS FETs and several built-in sensors. The amplifier also contains several types of protection functions like too high current, too high swr, too high temperature, etc.

This resource details the four primary functions of a ground system: lightning energy dispersion, equipment safety, RF return path provision for end-fed antennas, and management of induced RF currents. It clarifies that a ground system's effectiveness varies depending on its specific function, noting that a good lightning ground might not be an effective RF ground. The content emphasizes that proper antenna system design, including baluns and appropriate feedline lengths, often negates the need for an RF station ground to mitigate common mode currents or RFI in the shack. The article quantifies lightning energy, stating its peak is in the dozens or hundreds of kilohertz, with damaging energy extending to hundreds of megahertz, and currents reaching thousands of amperes. It recommends solid, wide, smooth copper surfaces for ground leads to achieve low impedance across a wide frequency range. The author, W8JI, shares practical insights from his station, which includes two 300-ft towers and four 130-ft wire verticals, detailing his use of common point grounds and _DX Engineering RR-8 HD_ antenna switches for lightning protection without coaxial surge protectors. Specific examples of antenna systems prone to common mode current problems are listed, such as random wire antennas without proper feedline lengths and off-center fed dipoles. The text also explains how a ground screen or radial system can reduce local noise sensitivity for vertically polarized antennas by covering the lossy earth.

This page contains ideas, hints and tips about Auxiliary Items that will help you to enjoy the sport of HF Contesting without emptying the bank account

Manufacturer of Select-A-Tenna Products since 1971 AM Radio Antennas

Decoding NOAA APT weather satellite images is achieved with a homebrew receiver and a Turnstile Cross Dipole antenna, feeding data to a Pentium-3 500MHz PC running Windows XP and the WXTOIMG program. This setup, operated by VU2IIA in Mumbai, India, focuses on capturing and processing signals from NOAA satellites to generate visual weather data. The blog documents the technical aspects of constructing the receiving station, including antenna design and receiver integration. It provides insights into the practical challenges and successes of amateur satellite reception, specifically for Automatic Picture Transmission (APT) signals. Operational details cover the software configuration and image processing workflow necessary to transform raw satellite data into usable weather imagery. The content serves as a practical guide for radio amateurs interested in satellite meteorology.

Using the Raspberry Pi to operate Weak Signal Propagation Reporter

The 2 Meter 146mhz Slim Jim Antenna using aluminum tubing!

The resource, initially identified as "Alabama Radio," a dealer of amateur radios, antennas, CB equipment, scanners, and power supplies in Eastern Alabama, now redirects to a domain brokerage service. The original intent was to provide a commercial outlet for Ham Radio operators and CB enthusiasts seeking new equipment and accessories. This would have included transceivers, antenna systems, and various station components. However, the current content at the URL is _Startup Domains_, a platform for buying and selling premium .COM domain names. This shift means the resource no longer serves the amateur radio community directly. Instead, it focuses on digital asset transactions, with no mention of radio equipment, _DXing_, or _contesting_ activities. The original description of a regional radio dealer is no longer applicable to the live content.

64MHz to 1,700MHz Software Defined Radio

Rigpix page for Kenwood TS-590S

Collection of accessories that makes the Yaesu FT-817 more enjoyable.

2 Meter Slim Jim Antenna Using 300 Ohm Twinlead

Italian site, for antique radios, with photos, collections, technical and forum

PC-based oscilloscopes, data acquisition and data logger products, spectrum analyzers and voltmeters

Building the double size G5RV antenna, part list, assembly part, dimensions and assembly instruction in a pdf document

This video shows one way to use a scope and function generator to measure the length of a piece of coax transmission line as well as estimate its impedance

Heathkit Amateur Radio Repair, parts, and manuals. Amateur radio equipment sales and service.

Speakers and RFI noise reduction products

Understanding Common Mode and Differential Mode Currents on Transmission Lines by K9YC

Negative feedback is often referred to as shunt feedback in conjunction with emitter degeneration.

NG3K DXCC Entity tables by prefix by ng3k

Presents a Brazilian online portal dedicated to **amateur radio**, **CB radio**, and shortwave listening (SWL) communities. The platform facilitates free classified advertisements for radio equipment, including HF, VHF, and UHF transceivers, antennas, and accessories. It also aggregates a substantial collection of technical articles from Brazilian amateur radio operators (e.g., PY2DJW, PY1LJ, PY1LL/4LC), covering topics such as CW training with RufzXP, balun importance, and radio wave characteristics. Furthermore, the resource provides extensive links to Brazilian ham radio sites, clubs, international organizations, and official ANATEL (Brazilian National Telecommunications Agency) documents regarding licensing, equipment homologation, and regulations. The portal features sections for user evaluations of transactions, a "Top Ten" list of most visited pages, and a calendar of past and upcoming ham radio events across Brazil, including "Feirinhas" (local swap meets) and "Encontros de Radioamadores" (hamfests). It also includes a directory of ham radio related businesses and services in Brazil, such as antenna manufacturers (Diex), QSL card printers (Arte Final), and repair technicians (PY2MOK). The site also offers propagation maps, DX cluster links (e.g., DX-SUMMIT), and satellite tracking tools, making it a central hub for Brazilian radio amateurs seeking to buy, sell, learn, or connect with the community.

KARSFEST, held at the Will County Fairgrounds. Sponsored by the Kankakee Area Radio Society. Large and well attended hamfest and computer show!

Free windows world map application display current time, sunrise and sunset, greyline map, dx stations, requires windows 7 or higher. The program includes three resized Natural Earth maps which have been resized to 4k or slightly less. By Simon Brown G4ELI better known as the inventor of Ham Radio Deluxe.

Premier company that offers advanced products and services to protect today's structures from lightning

Design and build an 6 m dipole antenna from aluminum, tubing, that resembles the active element of a yagi beam antenna.

Examines the Icom IC-2100H 2-meter mobile transceiver, detailing its operational characteristics and user experience. The review highlights the clear, easy-to-read display with internal labels, the button-filled microphone's functionality, and the rig's physical construction, including its weighty heat-sink and lack of a cooling fan. It also discusses memory programming, the unique amber-to-green backlight color options, and the radio's performance against _intermodulation_ in urban environments, noting it performs "pretty darn good" compared to other rigs. The analysis delves into a significant low-voltage cutoff problem, where the microphone ceases to function below approximately **12.6 VDC**, rendering the radio receive-only or causing it to stick in transmit. The author describes testing the voltage cutoff, observing it fluctuate from _12.38 VDC_ to 12.69 VDC. An update from Icom involved a "factory update" to the CPU's control code, which is strongly recommended for early-serial number units to prevent operational failure in low-power emergency scenarios.

Activating a county for ham radio can be dangerous to your health!

Spanish web site

The essentials of the parabolic reflector or dish antenna and its theory and design for high performance applications such as satellite transmission and reception as well as microwave links.

5-element antenna, with which G0JJL has worked lots of EU crossband, and won the RSGB Christmas Cumulatives 70MHz section twice in a row.

The European PSK Club, or EPC for short, is an informal club of amateur radio operators dedicated to maintaining high levels of amateur radio communications on PSK modes. Its purpose is to promote activity and good operating practice on the PSK modes on all amateur bands

HAM-IV antenna rotor repari and restore

The largest gathering of shortwave listeners (about 200) in North America, near Philadelphia in March.

The Yaesu FT-1000MP Mark-V, introduced at Dayton 2000 Hamvention, features a higher RF power of **200 W PEP** and a Class-A amplification SSB mode at 75 W. Key enhancements include an _Interlocked Digital/Analog Bandwidth Tracking system (IDBT)_, a Variable Front-End Filter (VRF) preselector, and improved ergonomics, notably a multi-function shuttle jog dial. This model, a successor to the 1996 FT-1000 and FT-1000MP, was designed to compete with high-end transceivers, despite its retail price of $4200 initially. The transceiver's physical dimensions are 406 x 135 x 348 mm (16 x 5.3 x 13.7 inches) with a weight of 14 kg (31 lbs), making it substantial. Its rear panel offers over 20 connections, including power, external DSP speaker, BAND DATA I/O, ALC, and multiple interface jacks for DVS-2, Packet, and RTTY. The unit also provides two keyer inputs, a DB9M serial interface for CAT, and two PL female antenna connectors, plus additional receive antenna jacks. Despite its advanced internal architecture, including two independent receivers with their own IF filters and AGC loops, the display technology, utilizing fluorescent discharge rather than LCD, contributes to an older aesthetic. The control panel is extensive, featuring 92 knobs and buttons, alongside numerous LED indicators for various modes and functions.

Digital amateur tv and mobile transmitting around Friedrichshafen and Lake Konstanz to be seen in Hall A. Heinz DC6MR is presenting the news, novelties and technical aspects of DATV.

Amateur radio good operating practices by KG9OM

This PDF document details the construction of a **70 MHz** Big Wheel antenna, a horizontally polarized omnidirectional array. The design utilizes three full-wave loops, each approximately **2160 mm** in diameter, arranged in a triangular configuration. The resource provides mechanical dimensions for the antenna elements and a comprehensive bill of materials, specifying component quantities and types, such as M8 stainless steel bolts, 15x15x1.5 mm square aluminum tubing for spacers, and 8 mm aluminum rod for the arcs. The central hub is constructed from two 160x160x8 mm aluminum plates, with four 40 mm long polyamide insulators supporting the radiating elements. The feed system incorporates a 50 mm diameter aluminum pipe for mounting and a matching stub constructed from a 120x20x2 mm aluminum sheet, connected via M8x10 mm bolts. The resource includes a diagram illustrating the mechanical dimensions and assembly points, including the N-connector fixing point and the center conductor attachment. The project was published on May 25, 2011, by Peter OE5MPL and Rudi OE5VRL. DXZone Focus: PDF | 70 MHz Big Wheel | Mechanical Dimensions | **2160 mm** loop diameter

Mountain Thunder CB Radio Group is a group of CB SSB operators that started in the Pacific Northwest, Washington State.

Analyzing a decade of contest operations and QSLing from March 1993 to March 2003, K5ZD presents data on QSO totals by band and mode, QSL error rates, and DXCC progress. The article details the author's methodology of only answering incoming QSLs, which allowed for a study of call copying error rates, found to be between 0.8% and 1.7%. These error rates correlate with typical contest log checking reports (UBN/LCR). The data also tracks the percentage of QSOs confirmed by QSL cards annually, averaging 12.1% over the ten-year period, with a steady rate of 14-15% in earlier years. Specific statistics include a total of 215,653 QSOs logged, with 26,184 QSLs received. The article identifies the top 33 countries for incoming QSLs, accounting for over 87% of the total, with Japan, Germany, Spain, and Belgium being prominent. It also touches upon the potential of ARRL's Logbook of the World (LoTW) for instant confirmations, while noting potential error rate implications. The author's station, initially a barefoot setup with a Hygain multi-band vertical, evolved into a fully operational contest station by October 1993, utilizing DX4WIN for logging.

About the Icelandic Alfa Tango members,DX,Iceland and all what has to do with the hobby.

Makers of oscilloscopes, spectrum analyzers, frequency counters, power supplies and more testi equipment products

Manufacturer of custom belt buckles,coffee mugs,t-shirts,sweat shirts,maine gifts,name tags,call tags and awards for police, fire, sheriff, ham radio and amateur radio clubs

Antennas for restricted lots, apartments and indoor antennas by VK3YE