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The Collins 516F-2 is a heavy-duty power supply for the KWM-2/2A transceivers and the 32S-1,2,3 series of Collins transmitters.

DIY a Wi-FI Helical Antenna for better performances, a project by PA0HOO i Dutch end English

Qucs, briefly for Quite Universal Circuit Simulator, is an integrated circuit simulator which means you are able to setup a circuit with a graphical user interface (GUI) and simulate the large-signal, small-signal and noise behaviour of the circuit. After that simulation has finished you can view the simulation results on a presentation page or window. Run on Linux.

The utility "NEC-2 for MMANA" is intended for calculation of antenna models made and optimized in program MMANA and for construction and simulation of antenna models using input language NEC-2 and based on MMANA models.

The HB9DHG Contest Calendar aggregates contest information, offering direct links to official rules and past results for various amateur radio competitions. It features a curated list of events, with a focus on HF and digital mode contests, ensuring that operators can quickly access relevant details for upcoming and historical events. The calendar is regularly updated to reflect the latest contest schedules and rule changes. Each entry typically includes the contest name, dates, and a direct link to the sponsoring organization's page, such as ARRL or DARC, where full regulations and scoring information are available. This resource streamlines the process of finding contest specifics, which is crucial for effective pre-contest planning and post-contest analysis. Validation and checking of contest information are emphasized, providing a reliable source for operators planning their contest activity throughout the year. The calendar supports both CW and SSB modes, alongside various digital modes.

How to identify correct version of your TS-570

Accurately determining an antenna's feedpoint impedance is crucial for optimal performance, especially when experimenting with new designs or making adjustments. While SWR meters provide basic information, a full complex impedance measurement reveals the resistive and reactive components, which are essential for proper matching. Modern antenna analyzers, like the _Palstar ZM30_ or MFJ259B, simplify this task, but measurements taken through a transmission line require careful interpretation due to impedance transformation. This resource details a calibration method to precisely account for the effects of the feedline. It explains how a transmission line can significantly alter the measured impedance, illustrating this phenomenon with a Smith Chart example where an 80m antenna's [22 + j6] Ohms feedpoint impedance transforms to [82 + j45] Ohms after a 10m line. The guide demonstrates using a transmission line calculator applet, such as the one by W9CF, to reverse this transformation. It outlines the process of calibrating a specific length of RG174 coax, showing how an initial 26ft estimate was refined to **25.85ft** to accurately predict a known 22 Ohm load, significantly improving accuracy over uncalibrated results.

Adjusting audio output of your soundcard to obtain a perfect PSK signal from your transmission. A project to help you tuning your PSK31 emission.

A SSB CW transceiver for six meters band with schematic and block diagram

Simple circuit, with a simple push, transmit a memorized Cw messages

10 Meter Beacon, 28.288 mhz Hurricane Uta USA

Make your own loading coils for antenna projects using Caterpillar Grommet strips.

This circuit consists of microphone amplifier and a high pass filter. Suitable to improve signal readability.

There is not a personal design on this page, just I've transfered useful notes from PHILIPS RF Bipolar Transistors - Data HandBook about BLY89C VHF Power transistor, which is very popular among Amateur Radio homebrewers

Repeaters available in or near Ridgecrest California, Amateur Radio License Examination Schedules

A 4 elements handitenna for 70 cm band. This is my version of the K5OE Handitenna. This one is a four Element instead of three, as I had less of a crunch on space than he did. The 1st three elements (Reflector, Driven Element, and Director 1) are the same dimensions as his were.

Personal Web Site of UX7CQ. Information about Ukraine. Old military radios collection. CW Straight Keys.

Australia, Sydney Fire information and monitoring website, Live sydney radio fire stream.

A power line noise eliminator designed to eliminate QRN expecially on 40 meters band.

Approximately 800 x 600 resolution is recommended for optimal viewing of the _Connecticut Radio Society_ (W1CRS) website, which serves as a hub for active amateur radio operators. The site encourages participation in club activities, particularly emphasizing operating events and contests. It provides a digital presence for members and prospective members interested in local ham radio engagement. The society's focus includes general amateur radio operation and competitive contesting, aligning with its classification as a contest club. The resource is designed to foster community among hams in Connecticut, offering a point of contact for those seeking to engage with fellow operators and participate in organized radio events. The club's callsign, W1CRS, is prominently featured, signifying its identity within the amateur radio community.

Provides a robust contest logging solution for Windows users, supporting over **500** distinct amateur radio contests. The software integrates _digital modes_ and offers comprehensive logging features essential for competitive operating. It facilitates efficient entry, real-time scoring, and post-contest log submission in standard formats. Developed and maintained by K1LZ and a dedicated team, DXLog.net is provided free of charge to the amateur radio community. Users can access support and report bugs via the dedicated groups.io forum, ensuring ongoing development and user assistance. The platform includes detailed release notes and an archive of support information, aiding operators in maximizing their contest performance.

The Fence Fan Dipole a quick, easy and inexpensive multiband dipole antenna

The resource details the construction of a **Hustler-compatible** HF mobile antenna mast, utilizing 1/2-inch copper water pipe and common hardware. It provides a bill of materials, specifying one 10-foot copper pipe, four 1/2-inch copper end caps, and 3/8-inch fine-thread hex bolts and nuts, totaling $8.75 for two masts. The construction process outlines preparing bolts by rounding their heads, drilling 3/8-inch holes in end caps, soldering bolts into caps, and then soldering these cap/bolt assemblies to 5-foot sections of copper pipe to achieve a final length of 54-1/4 inches per mast. The method emphasizes precise soldering techniques to ensure structural integrity and proper fit. The resulting masts are presented as functional alternatives to commercial units, with the author noting their performance is comparable to the "real thing." Installation tips are provided, including the use of braces connected to a trunk lid to mitigate stress on the antenna mount, contrasting this approach with WA8WTE's spring-based method. Photos illustrate the completed mast mounted on a vehicle, demonstrating practical application and support strategies for mobile HF operation, particularly with larger coils and longer whips at highway speeds.

Ham Radio community web site

PCB for the DJ9BV Power Meter taken from DUBUS 3/87

This article describes a simple Inverted L antenna for the HF bands designed to work on 80m, 40m, 30m and 20m

Myths and basic truths on transmission lines

RF Power Meter using for reading a standard Digital Voltmeter by Iulian Rosu, YO3DAC / VA3IUL

Association with free membership for telegraphy lovers across the world.

W0IPL experiences with Ten-Tec Jupiter

A magnetic longwire unun with a T130-2 Iron Powder core by M0UKD

conversion of low band VHF Philips FM-828 E band down to 6 metres

The GM4JMU Shortened 7Mhz Dipole

Comparison of 50 and 70 Mhz antennas, commercial and home made projects

a methodology for connecting multiple LF/MF/HF receivers to a single antenna via readily available and inexpensive 75-ohm TV cable.

Battery problem with TS-570

Calculate power loss depending on coax cable you use

Ham Radio Class On-Line. A complete On-Line Course for the Technician, General or Extra Class amateur radio license.

Antenna Rotor Control Software for Windows and Linux is a companion project to the arduino rotor controller.

This little project will make a portable 28 Volt DC power supply using two 12 Volt, 4.5 Ah rechargeable lead-acid batteries

An easy portable VHF antenna to build for ARES - RACES work is the 300 Ohm Twin Lead JPole antenna

This page describes a DC to DC voltage converter, pretty simple, for currents up to 500 mA by sv1bsx

FreqTweak is a tool for FFT-based realtime audio spectral manipulation and display for Linux, offering various algorithms for audio processing in the frequency domain and an interactive GUI. It provides high-resolution spectral displays like scrolling-raster spectrograms and energy vs frequency plots.

Demonstrates the construction of a _3MA triband mobile antenna_ designed by IZ7DJR, emphasizing a full-size quarter-wave whip for 10 meters. The design incorporates a rapid tilt-down mechanism to facilitate quick changes of loading coils for operation on 15 and 20 meters. This approach aims to minimize losses and enhance efficiency compared to conventional base-loaded mobile antennas. The resource provides specific coil winding data: 22 turns for 15 meters and **37 turns** for 20 meters, both using 1mm wire over an 80mm coil length. The 10-meter band operates without a loading coil, leveraging its full-size design. The author's design prioritizes ease of band switching and improved performance for mobile HF operations, offering a practical alternative to more lossy commercial options.

A homebrew Magmount for 2m antenna

Many official FCC forms available in Acrobat PDF format.

Comparison of performance between an indoor random wire versus a magnetic loop using psk31

Online database: downloadable database, updated monthly. In norwegian.

The Trans Provincial Net meets daily on 7.055 Mhz, 7am to 6pm EST daily

Pneumatic Antenna Launchers for sale