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

Amateur Packet Radio Gateways by dl1eis

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

An RF power supply for 144 MHz schematics and instructions

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

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

FAR Circuits is exclusively a manufacturer of Printed Circuit Boards for electronic projects that are used by the Amateur Radio and electronic hobby enthusiast.

Radio Resources for PMR 446, Scanning, Broadcast and CB Radio

Add-in module to Microsoft Excel, contains a set of radio amateur relevant special functions: DistSphericLocator(Loc1; Loc2) Calculates the spheric earth model distance between two locators [km] DirSphericLocator(Loc1; Loc2) Calculates the spheric earth model direction from Loc1 to Loc2

Eham review for ICOM IC-706 - All flavors

Why Beverages need good transformers by VK3APN

PA5DD version of the dual band yagi antenna for 50 and 70 Mhz

RCI web site

RF power meter, dummy load, project

High Voltage Supply for GS 35B Amplifier

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

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.

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.

Large collection of audio clips of foreign radio stations, with identification announcements in various languages, signature tunes and jingles, and of course interval signals.

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.

Useful data-sheet on RG coax cables compiled by NA5N

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

A magnetic loop antenna calculator made with an excel sheet that run also with open office, let you design mag loop antenna dimensions by AA5TB

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

Recordings of shortwave numbers stations

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.

9K2GS WEB Page

This purpose of this page is to give a brief description of a 70 MHz transverter that has been published in the Danish amateur radio magazine "OZ"

QSL and Label printing addon to Ham Radio Deluxe by IW1QLH

A delta loop antenna for 6 meters band with SWR diagram , construction plan and some pictures by IZ8EWD in Italian

Excellent poster representing the electromagnetic spectrum from 31.2 mHz to 6.52 EHz, PDF file poster designed by Anthony Tekatch

G3TXQ pages focuses on understanding the HexBeam antennas. Basics, dimensions, multi band issues, antenna modeling.

Military collection Cold War Nike Msl Site

Remotely controlled antenna switch that can switch between 5 antennas

VA3EXT 5 element beam antenna for 6 meters band

Here is a way to ease assembly and balancing of a large antenna. The elements and boom are assembled separately in most cases. Once they are all together set up 2 tripods in the assembly area and put the boom on them.

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

Supplier of custom designed, high performance quartz crystal filters for communications receivers and transceivers, for Yaesu Icom Kenwood and Collins radios

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

Excel spreadsheet that help calculating dimensions of a high efficiency magnetic loop antenna for HF bands. Giving in input the loop perimeter, loop diameter and loop conductor will calculate electric characteristics, bandwidth, and efficiency

eham members Yaesu FT-857 and Yaesu FT-857D reviews

OM International sideband society incorporated nets 75M, 40M, and 20M Nets begin one hour earlier during Daylight Savings Time