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Low Noise Antenna pre-amp for SAT, EME & DX-ing

Simple program for ham radio Uses AX25 support built in Linux kernel, works in X11 graphics environment.

VU2VWN project to homebrew a CW for 40 meters band

Article by WB3GCK on 4 to 1 Un-Un

This circuit provides an interface between the Yaesu 920 transceiver and IBM computer sound card which allows data transfer and control of PSK31, RTTY, KEYBOARD CW, and SSTV modes for Amateur Radio

This array has been in use since 1989. The SWR from 3.5 to 3.9 is below 1.5:1. The F/R of the array is 20dB average and with some signals even better.

This page displays a 404 error, indicating the original content describing a simple _RS232 interface_ circuit is unavailable. The circuit was reportedly designed for older Kenwood transceivers and featured in chapter 22 of the _ARRL Handbook_. It likely involved basic electronic components for level shifting and signal conditioning between a computer's serial port and the radio's control interface. The intended project would have detailed the construction of a hardware interface, enabling CAT control for specific Kenwood models. Such interfaces typically convert TTL or CMOS logic levels from the radio to the +/-12V levels required by RS232, often utilizing ICs like the MAX232 or discrete transistor circuits. While the specific schematics and bill of materials are absent due to the page error, the context suggests a DIY electronics project for enhancing legacy amateur radio station functionality through computer control.

A three tube regenerodyne receiver by Gary Johanson, WD4NKA

More links to Icom IC-746 resources on the web

Applying for an FCC vanity call sign requires navigating the _Universal Licensing System_ (ULS) database to identify available call sign blocks and specific desired combinations. The process involves submitting an online application via the FCC website, ensuring all instructions are meticulously followed to avoid rejection. Typical processing time for a vanity call sign application is approximately **18 days**, after which the ULS database reflects the updated license grant. Operators often seek vanity call signs for various reasons, including aligning with a new license class, desiring a shorter call sign for CW efficiency, or simply preferring a more memorable phonetics. The resource emphasizes self-application to avoid third-party service fees, directing users to verify availability through tools like Vanity HQ. Key steps include selecting a primary call sign and several alternates, ensuring the chosen call sign conforms to FCC rules for the operator's license class. Payment can be made online or via check, with prompt submission critical to prevent application dismissal.

An interesting and very detailed report analysis of three populare HF+6m transceivers. Yaesu FT-950, ICOM IC-7410 and the Kenwood TS-590S by AB4OJ

A site exclusively meant for the novice. Find all the information necessary to become an amateur radio operator! More India specific information.

Web Site of CB Radio station from Vernadsky Research Station on Galindez island 140URL9909

This page shows W5AJ & KD5AAU setting up a self supporting crank over tower.

An RF power supply for 144 MHz schematics and instructions

Why Beverages need good transformers by VK3APN

Memory manager for ICOM IC-706 MKIIG, IC-737, IC-7000, IC-746, IC-756 ProIII, Kenwood TS-570D, TS-570DG, TS-870, TS-2000 and Yaesu FT-920, FT-1000 , FT-2000, run on windows, free by OH2KXO

RF power meter, dummy load, project

A portable 4 elements quad antenna for 144 MHz, 9 to 10 DBd forward gain, 30 DB front-to-back ratio, and 33 DB front-to-side ratio

High Voltage Supply for GS 35B Amplifier

Low power VHF RF amplifier with VMP1 Mosfet by IZ1BTS IK1XPD

UJYSAT is a new software for satellite tracking written by IT9UJY, This software is totally free for Amteur Radio only.

My first homemade SSB and CW receiver 10 kHz to 30 MHz

Yaesu, Kenwood, Icom repair service

This antenna consists of 4 resonate dipoles made from 12 insulated copper electrical wire. The dipoles are resonate on the following bands: 6 meters, 10 meters, 12 meters and 17 meters.

Useful data-sheet on RG coax cables compiled by NA5N

Some of the interesting shots of the W5AJ Rohn 25G tower

A magnetic loop made just of wire. Suitable for portable usage and for QRP operations.

Presents a detailed construction guide for a **Quadrifilar Helix Antenna** (QHA) optimized for 137 MHz, specifically for receiving weather satellite transmissions. The resource outlines the author's experience building previous QHA designs, highlighting challenges with tuning and nulls, and then focuses on a refined design by John Boyer, documented by Steve Blackmore, which proved easier to build and yielded superior reception. The guide provides precise element dimensions, including 1.5m of 32mm PVC pipe for the mast and 8mm soft copper tubing for the helix elements. It specifies lengths for horizontal tubes (190mm, 90mm) and helix elements (903mm, 1002mm), along with instructions for drilling, assembly, and forming a **balun** by wrapping RG58 coax around the mast. The text emphasizes critical steps like ensuring elements are square and twisting in the correct direction to avoid phase issues. It includes references to original QST articles by Buck Ruperto (W3KH) and the WxSat program for decoding satellite transmissions, contextualizing the antenna's purpose. The article concludes with a sample NOAA 12 image from September 1998, demonstrating the antenna's reception capabilities.

Calculate Cable Loss from SWR and reverse. Text file with only two simply formulas

9K2GS WEB Page

Operating Slow Scan Television (SSTV) on Apple macOS systems requires specialized software to encode and decode images for transmission over amateur radio frequencies. MultiScan 3B was an application designed for this purpose, enabling Mac users to engage in SSTV communications. It supported various popular SSTV modes, including Robot Black & Color, Scottie, Martin, PD modes (P3, P5, P7), and AVT, catering to a wide range of operational preferences and compatibility requirements within the SSTV community. The software's capabilities extended to both transmitting and receiving pictures, offering flexibility in how images were processed. Users could select regular, narrow, QRM, and narrow+QRM modes, allowing for adaptation to different band conditions and signal environments. This feature was particularly useful for mitigating interference and optimizing image quality during transmissions on HF bands. MultiScan 3B was built to run on Mac OS X 10.6 and later versions, providing a dedicated solution for Mac users interested in this classic digital mode. Its support for multiple modes and operational settings made it a versatile tool for SSTV enthusiasts.

A pdf file with schematics of an ssb and cw filter AF amplifier

Yaesu MD-100 microphone schematic wire diagram with pin out

Here is an easy method to mount elements to a boom, this can be realized at home, without the need of special tools

W3DZZ trapped multi-band antenna, exposed in this practical wireless article

Projects and design atv de ik1hgi Progetti, circuits, master, fotos in Italian

Yaesu FT-1000 review edited by G3CWI

Deciphering weak or noisy **CW** (Continuous Wave) signals often presents a challenge for amateur radio operators, particularly in contest environments or during DXpeditions. CWLab04X addresses this by providing a software solution that leverages **DSP** (Digital Signal Processing) capabilities of a soundcard to decode Morse code. It functions as both a receiver and a sender, supporting traditional CW and a unique "CCW" mode designed to enhance copyability of signals struggling against high noise floors. The program offers two installation methods: a Windows-specific installer for straightforward setup or a zipped package compatible with Windows and Linux systems running Wine. Users must first download and review the accompanying PDF documentation, CWLab04.pdf and CWLab04_Hardware.pdf, which detail the software's operation and the necessary soundcard interface circuit. The hardware PDF outlines a direct connection from the receiver audio output to the soundcard input, with optional conversion of the soundcard output for hard-keying or microphone input. CWLab04X is intended as an operational aid rather than a replacement for skilled human copy, particularly highlighting the effectiveness of its CCW mode in adverse signal conditions. The software was last revised in April 2009, with installation requiring the LV Runtime 602.

Very compact and high efficiency antenna ,very low radiation angle even at low height.

HF and VHF amplifiers homebrewed by GM3WOJ

Complete CW CODE signs

Diagram and sample ferrite balaun for 1.8-30 MHz

Understanding high-frequency (HF) skywave propagation is crucial for amateur radio operators seeking to optimize long-distance communications. This resource details the fundamental principles of HF radio propagation, including the properties of electromagnetic waves, the characteristics of various HF bands, and distinct propagation modes such as skywave, ground wave, and line-of-sight. It places significant emphasis on the ionosphere's pivotal role in refracting HF waves, explaining how solar activity directly influences ionospheric conditions and, consequently, propagation paths. The resource integrates real-time monitoring capabilities, featuring dynamic charts and data from DX clusters, WSPRnet, and the Reverse Beacon Network, which allow users to track current band activity and propagation conditions globally. It also delves into advanced topics like Near Vertical Incidence Skywave (NVIS) and gray line propagation, providing insights into ionosonde data and various propagation prediction models. The site presents a detailed analysis of solar-terrestrial interactions, geomagnetic indices, and space weather phenomena, illustrating their direct impact on HF communication reliability. Practical tools and applications are highlighted, including real-time QSO planners, online Maximum Usable Frequency (MUF) maps, and alerts for solar flares or geomagnetic storms. The guide systematically breaks down complex concepts into accessible chapters, offering a structured approach to learning about ionospheric regions, diurnal and seasonal effects, and the interpretation of propagation indicators like foF2, MUF, and Lowest Usable Frequency (LUF). This makes it a robust reference for hams aiming to deepen their technical understanding and improve operational effectiveness.

This webpage describe how to set up the Signalink USB interface and Yaesu FT-857D for digital operations by NA4IT

This is a compact three transistor regenerative general coverage receiver with fixed feedback

G4PDQ's PacketCluster routines to make PacketCluster a little more interesting for the user and a little easier for the SysOp

Homebrew antenna insulators for DK7ZB yagi antennas

Amplifier keying buffer for ICOM radios & others. Suitable for IC-746 IC-756 PRO and PROII. ACC1 key interface by KK5DR