Search results

Constructing a Compact Low Cost Sprinkler Valve Antenna Launcher

Over 45 years of dedicated work by Robert Sherwood, NC0B, culminated in a wealth of technical insights, particularly concerning **receiver performance** and the intricacies of transceiver design. The site provides access to numerous presentations from events like Dayton Contest University and W4DXCC, covering topics such as optimizing rig performance, the evolution of lab testing, and the impact of roofing filters on transmitted IMD and receiver characteristics. These resources offer detailed analyses and practical advice for serious operators and contesters. While product manufacturing, including the SE-3 MK IV synchronous detector and various Drake R-4C accessories like roofing filters and cooling kits, has ceased, the legacy of technical documentation remains. The site details specific products like the Icom IC-781 and R-9000, and offers insights into 455 kHz mechanical and crystal filters, along with DSP protection strategies. Crucially, the site features extensive receiver test data, allowing radio amateurs to compare the performance of various transceivers. This data, often presented in white papers and slide shows, includes detailed measurements and explanations of key performance metrics, serving as a valuable reference for understanding and selecting high-performance HF gear.

Ham Radio Class Exam question pool effective 7/01/2010 thru 6/30/2014

Graph of the frequency response of some of the legendary microphones favoured by radio hams

This online WebSDR is located near Corinne, Utah, has coverage on all U.S. amateur HF, MF and LF bands, 2 meters, the bottom 1 MHz of 6 meters, and several shortwave broadcast bands.

A home made field strength meter wit detailed pictures and schematic diagram by W4ZT

PropNetPSK is a PSK (Phase Shift Keying) program capable of receiving multiple signals (2 - 16) at one time for the exclusive use to decode a properly formatted PropNetPSK beacon signal. If you are looking for a Keyboard to Keyboard type of program, this will not fit your bill.

The Amateur Radio Association of Bahrain (ARAB) was established in 1970 to support the amateur radio community within Bahrain, operating under the **A92C** callsign. This organization provided a central point for local hams, fostering activities and representing their interests for several decades. Its historical presence is noted, even though it is no longer active. Unfortunately, due to unforeseen circumstances, ARAB ceased its operations. However, a new amateur radio society has since been formed in Bahrain, continuing the tradition of supporting local hams. Interested individuals can contact Fawaz, **A92AA**, for details regarding membership and the new society's activities, ensuring continued amateur radio presence in the region.

Building a Resonant Feed line Dipole for 2 Meters

Operating a modern amateur radio station often involves integrating various software tools, and LogHX aims to provide a unified environment for Windows users. The software facilitates comprehensive QSO accounting, allowing operators to track contacts and manage both e-QSL and traditional paper QSL exchanges, including via QSL managers or direct methods. It also offers real-time QSO preview and integrates with popular callbook data for quick lookups. LogHX supports various logbook database searches and maintains statistics for numerous awards, a critical feature for serious DXers and contesters. The program handles logbook import and export in widely used formats such as _ADIF_ and _Cabrillo_, ensuring compatibility with other logging applications. Furthermore, it interoperates with Telnet clusters and third-party ham radio software, enhancing its utility in a networked shack environment. Key functionalities include antenna rotator control, editable macros for PSK, RTTY, CW, and SSB operations, and CAT control via _OmniRig_ or direct interfaces. Embedded modules like MMVari, MMTTY, and CWServer streamline digital mode operations, while its multi-window structure allows users to customize their screen layout, preserving valuable monitor space.

GAL-ANA is an Antenna-Analyzing Tool software, based on NEC2/MININEC3m engines currently available in demo mode for download

The direct conversion receiver described consists of only a bandpass filter, mixer IC, VFO and audio filter. With only 22 parts, this simple circuit should take a few hours at the weekend to construct.

VK9MT Online Log Search - Mellish Reef 2014

A little information about my equipment, qsl cards etc.

Personal site of Russian DXer Dmitri Mezin. Contains a fresh edition of his Signal bulletin, archive of all previous issues and QSL gallery.

Contesting, CW, antennas and review on TK/OE5XVL DXpedition 1999 plus my GD/OE5OHO DXpedition in 1997.

Running D-Rats on a Raspberry Pi documentation and instruction by n0so

About Switchable Direction EWE Antenna

The function of the XPhase is based on the fact that the interfering signal, received by an auxiliary antenna, is added phase-shifted to the signal received from the main antenna. When the phase-shift is more or less 180°, the interfering signal is canceled out.

Personal web page of Gerardo Pe?a. From Cuenca, in the South Center of Ecuador.

There are several reasons that can cause coax line radiation, most of them are related to wrong or missing use of a balun, but none can be imputed to load mismatch.

DXpedition by Jorge/OA4BHY, Rene/DL2JRM, Bodo/DL3OCH, Daniel/DL5YWM

Searchable database of amateur repeaters and broadcast transmitters. The database covers the fifty U.S. states, the District of Columbia, and the ten Canadian provinces.

Port of the popular VOACAP program, HF propagation prediction tool. It may be compiled using the GCC GFortran compiler

Index of main electronics topics

BI5D The archipelago of Dongtou.

A test and comparison of real attenuation of N-type connectors and PL-259 connectors on UHF bands, domonstrating that connectors are almost equivalent.

Learn quadrature modulation through interactive flash programs. These programs will allow you to learn about quadrature modulation and quadrature demodulation without getting overwhelmed by math.

Online Log 9U4U

This program converts an ADIF report file from ARRL's Logbook of the World (LoTW) to comma-separated value (CSV) format so that it can be read into a spreadsheet program like Microsoft Excel.

Meetings Schedule, study groups, circulars from the radio communication division at ITU

link7 is a Windows 9X program to download/upload data from/to the Kenwood TH-D7.

How to measure the characteristic impedance of a unknown transmission line using MiniVNA

Adapting a Wouxun/Kenwood USB cable as a Yaesu FT-817 FT-857 FT-897 CAT connection

This app permit to work in DigiModes using the latest free version of HamRadio Deluxe Suite 5.24.0.38 with the new Yaesu FT-991 (which is not supported in that version of the application) using the Yaesu FT-950 model in HRD

The Four Metres website offer a global overview graph of the four meter band plans world wide

An illustrated modification for the Icom IC-R20 receiver to locate and use the unfiltered audio.

Design a parallel circular wire balanced transmission line with this online calculator. This calculator is a tool for designing balanced transmission lines with a specific desired characteristic impedance Zc and made of parallel circular conductors of a given diameter d.

What's all this stuff about LowFERs, MedFERs and HiFERs? What Is 'Part 15?'

Performance of an unloaded ground mounted vertical as a multi-band HF antenna.

Refurbishing my 10 years old Cushcraft A3S triband HF Antenna

The ZL1BPU Rotator Controller has been designed as an add-on unit for the popular Kenpro KR-400 and Yaesu G-400 rotators. The controller consists of a small circuit board which fits inside the rotator control box

Tait electronics provides advanced and reliable voice and data radio communications products and solutions, specialising in customised solutions for organisations worldwide.

Macedonian press agency

CASPERARC amateur radio club in Casper Wyoming

T index explained BY NOAA

The complete Bozo's guide to JT65A by K3UK, learn how to install and operate WSJT software and start making QSO in weak signals operating modes

Solar Flux, Geomagnetic Activity indexes and interpreting their relation

SkookumLogger is a free contest logging program for Mac OS X 10.7 or later, supporting CW and SSB events on the six HF contest bands plus 6m, 4m, 2m, and 70cm

An interesting article on how build an optimal sounding communications loudspeaker capable to optimize sound reproduction at the frequency range from 150 Hz to 3 kHz.