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Radio monitoring and analysis tools. Scanning, searching, spectrum analysis and traffic analysis. Amateur, Industry & Government,

Even if using a tuner this multiband antenna will let you operate from 160 to 10 meters. If you could only put up one antenna, this would be it. Project by N0KHQ.

Drawings pictures and notes on a rotary dipole antenna for 30 and 40 meters band

One is an EFHWA for 20-40 meters, and the other is a matching unit for the antenna by n0lx

Download JT65-HF Amateur Radio software for reception/transmission of JT65A protocol with an emphasis upon its usage in the High Frequency Amateur Bands. This is the W6CQZ version not developed anymore.

Yet Another Navtex decoder is a windows NAVTEX decoding software

How to select an antenna for scanning. This is a Readers Digest version of antennas, meant to give new users some idea of the different antennas and their good and bad points.

Base, mobile marine and cb antennas

Mods.DK serves as a central repository for **amateur radio modifications**, offering a substantial collection of user-contributed articles. Hams can find detailed instructions for various equipment, from transceivers by Yaesu, Kenwood, and Icom to microphones and power supplies. The database, currently holding 6230 articles, facilitates searching for specific equipment modifications, such as enabling out-of-band receive and transmit capabilities or integrating high-speed packet modems for enhanced data communications. Many entries focus on achieving better performance from existing gear, often detailing how to expand frequency coverage for MARS/CAP operations or optimize radios for 9600 baud packet. The site also includes repair instructions and general improvements for a wide array of HAM rigs and modems, reflecting a community-driven effort to share technical knowledge. Users are cautioned that modifications are not verified by Mods.DK and are undertaken at one's own risk, with potential legal implications depending on local regulations. The platform emphasizes community support, encouraging direct contact with authors or forum discussions for troubleshooting.

This antenna is intended as a simple, inexpensive solution for the newcomer to experiment across the 40m band (7.0-7.2MHz) when only restricted space is available

Retrospective of a mark now disappeared. Jumbo, Multimode, Concorde, Puma, Viking. Photographs, diagrams, adjustments etc.

Article designed to answer basic questions about antennas

A 14 Mhz version of the vertical moxon antenna homebrewed.

This page discribes microphone wiring connections for most UK and foreign radios. Most U.S. radios are "Code Type 2".

WSJT-X, a creation of K1JT, offers specialized digital protocols meticulously optimized for challenging propagation paths such as EME (moonbounce), meteor scatter, and ionospheric scatter. This software excels at VHF/UHF frequencies, and also provides robust performance for LF, MF, and HF DXing, enabling contacts far below the audible threshold. The program decodes signals from ionized meteor trails and steady signals more than 10 dB below the audible threshold, a testament to its advanced digital signal processing. It integrates nearly all popular features from its predecessors, WSJT and WSPR, while adding comprehensive rig control and numerous other enhancements for the serious weak signal operator. Available for Windows, Linux, and Mac OS X, WSJT-X is an open-source project, allowing hams worldwide to download the latest versions and engage in cutting-edge weak signal communication.

Calculates grid squares from latitudes and longitudes, the reverse, and calculates distances and headings from two sets of lat/long or grid square. Convert Grid Square to Lat Log and vice versa. Freeware for Windows

Complete DXCC list in a plain text file updated by ARRL

This page describes the design and construction materials W8WWV used to build a coaxial cable trap. A coaxial cable trap is a parallel resonant circuit that is usually inserted in an antenna element to enable multiband operation.

The _Astron RS35m Power Supply Schematic_ provides a detailed circuit diagram for this popular linear power supply, focusing on the rectifier and pass transistor stages. It presents the AC input and DC output sections, illustrating the component layout and interconnections critical for understanding its operation. The schematic is enhanced with specific annotations derived from the December 2005 QST "Hands-On Radio, Experiment #35 Power Supply Analysis." These notes offer insights into the circuit's functionality and potential analysis points, making the diagram more instructive than a bare schematic. The resource serves as a practical reference for hams interested in the internal workings or maintenance of the _Astron RS35m_ unit. This document specifically highlights the key components responsible for voltage regulation and current delivery.

Concentric Open Loop Antenna Fed Off-Centre similar to the cobwebb antenna but resonating on 20-17-15-10 meters band

Guide to calculate effective gain of antennas

80m to 23cm beam antennas, oscar antennas, and antenna rotors

Contain schematic diagram of many different radio, and some operations instructions.

Live streaming audio of Ontario Police Department. Super clean receive and high quality audio.

Sardine Can Antenna. is a BiQuad or Bi circle - wire length each side (8 x 1/4 waves ) 31 mm

Designed to work with all the major ACARS data capturing programs and enable users to get a complete picture of all the aircraft in there database, where they go and what they have done in the past.

An informative page about delta loop antennas

Proposed frequencies for PSK31 QSO

The FT-817 is a small 5W MF/HF/VHF/UHF transceiver with internal batteries. Here is an assortment of technical information K6XX put together about this rig that might interest you.

Multiplatoform freeware DSP software. Linrad has its origin in software that was developed for 144 MHz EME CW but it is quite general and should be seen more like a kit for designing a receiver that a receiver for some particular usage. It can be used as a CW receiver with a small time delay and a fast waterfall graph. A dsp for conventional receiver to imporve signals readability, a spectrum analyzer.

The finest in VHF/UHF antennas for Amateur and Commercial Applications. Antennas and Repeater Controller Accessories includes Rutland Arrays.

IRAQ War Military HF freqs, Aero HF frequencies and Shortwave Broadcast schedules of interest

Listen to the Baltimore County Maryland Police Live Scanner Radio Feed.

Article by Ed WE6W on a double bazooka antenna

Modified version of the Telerana antenna which was orginially featured in the July 1979 issue of QST. The array is suspended within a framework made of fiberglass poles emanating from a central hub with the ends tied together with light weight rope around the perimeter. 10-15-20-30-40 meter band coverage

Moxon antenna for 50 MHz, The Moxon rectangle is a quite broad-band antenna, but it is not quite broad enough to cover the entire band.

Demonstrates _Freq51_ and _Specgrm2_, two analysis programs from the Biomedical Ultrasonics Laboratory at the University of Michigan, available for DOS or Linux. The _Spectrum Analyser (Freq51)_ provides power spectrum levels as a function of frequency, configurable for absolute values (e.g., dB re 1 volt) with sound card calibration. _Spectrogram (Specgrm2)_ generates a real-time, full-screen spectrogram (sonagram) with various color options. These programs analyze incoming signals in real time, not stored files, and offer extensive settings for sampling rate, FFT points, and averaging time, making them highly versatile for acoustic analysis. The DOS version of _Freq51_ and _Specgrm2_ can operate under Windows 95, requiring users to configure sound card switches via a text file. The resource also briefly mentions other acoustic analysis software like Gianni Pavan's DOS-based bioacoustic tools, _Gram_ by R.S. Horne for Windows, _SASLab_ (Light and Pro versions), _Cool Edit_, and _GoldWave_, providing a comparative overview of available tools for real-time and file-based spectral analysis and waveform manipulation.

Manufacturer of the world's most dependable radio communication products

Kent Morse keys, used by amateurs and professional alike, renowned for their quality and reliability.

Austin Amateur Radio Supply, online amateur radio store.

Complete 144/50 MHz transverter with GaAs Fet LNA and 400 mW out. No printed circuit board. Schematics and images by Christoph Petermann DF9CY

This is a project to develop an Open Source reference design for a 1500 watt solid state linear amplifier for 10 through 160 meters by K6IF

2el 40Ft front to back spacing 80 meters Quad antenna

40 meters band Delta loop antenna plan that is vertically polarised

Log4OM is a free logging software designed for amateur radio operators who require an integrated environment for station management and QSO logging. It is widely used by DXers due to its strong database capabilities and its integration with common online services. The program uses a structured SQL database and supports large logbooks without noticeable performance degradation. One of its key features is **CAT Control**, which allows direct communication with many transceivers for automatic frequency and mode detection. The **DX Cluster Client** provides real-time spotting with filtering and band/mode tracking, helping operators quickly identify new DX opportunities. Log4OM integrates with several external confirmation systems. Built-in support for **Logbook of The World (LoTW)** and **eQSL** allows automatic upload and download of confirmations. The software also includes **Award Tracking**, enabling operators to monitor progress toward DXCC and other award programs directly from the log. Additional capabilities include **Callbook lookup** via services such as QRZ, **ADIF import/export**, and customizable **QSL management** for both electronic and paper cards. The interface is modular, with panels that can be arranged depending on operating preferences. Log4OM does not include integrated digital mode engines, so digital operation normally relies on external programs such as WSJT-X or FLdigi connected through standard interfaces. Overall, Log4OM provides a comprehensive logging environment suitable for both casual operation and serious DX chasing, with a feature set comparable to many commercial logging applications.

ZZ Wave Net is a 40 & 80 meter full wave loop designed to fit on a city lot. ZZ Antenna is a folded dipole bent into an inverted V loop

Dispels myth about choke balun winding method

This free software is useful for visualizing terrain and performing Longley-Rice path loss and coverage prediction using the Irregular Terrain Model. A Windows port of the Linux-based SPLAT by John Magliacane.

How To Build Code-Practice Apparatus: A Simple Telegraph Key

What is the best balcony antenna? what antenna would you recommend for use on typical hotel balcony? Read some answers here