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Pipe your signals to 146 and 445 MHz with one antenna!

The document is a technical guide on designing RF filters for radio frequency applications. It covers topics such as interference suppression, band-pass filters, and low pass filters, with a focus on filter design and circuit filters.

Why twinlead isn't necessarily a low loss feed line.

Cheap UHF antenna plans for 2 meters and up including 421 1296 and 902 Mhz

A PDF presentation of a home made moxon antenna for 50 MHz 70 MHz and 144 Mhz. The project is mainly out of surplus plastic Plumbing pipes and clips etc, and also details of how the dimensions were calculated.

JT65 is a digital protocol intended for Amateur Radio communication with extremely weak signals. It was designed to optimize Earth-Moon-Earth (EME) contacts on the VHF bands, and conforms efficiently to the established standards and procedures for such QSOs.

Homebrewing a mic boom headset for the Yaesu FT 897 and 857 transceivers

IC820H or other Icom Radios Soundcard interface for VHF EME use by DF9CY

By Jim Davey WA8NLC

Original Tuna-Tin 2 QRP CW transceiver article by W1CER

A simple VHF vertical aerial for the home station

RF and Microwave Power Amplifier and Transmitter Technologies, amplifierlinearity, efficiency and available RF power devices.

The Considerate Operator's Guide shows frequencies generally recognized for certain modes or activities (all frequencies are in MHz).

Table of Frequency Allocations as published by the Federal Register and codified in the Code of Federal Regulations remains the legal source material.

ARRL review ICOM IC-756 pro III HF/6 meter transceiver at central michigan ARC PDF File

Australian amateur radio band plans in pdf format

Using MFSK mode, 98 Kb PDF doc, taken from QST January 2001

Service manual in PDF Format for the Yaesu FT-7800 transceiver

Understanding and solving RF interference problems using ferrite

The Kenwood TS-2000 All-Mode Multiband Transceiver review

Building a high voltage (5KV), variable plate capacitor (17 to 220pF)

A 2-metre Quad antenna project by K6WXA in PDF file

A 5 band two element quad antenna working from 20 to 10 meters using hardware-store parts or modifying an existing commercial triband quad by KC6T

Balun case construction, tipically to host toroid cores. Size of case depends on power to handle. By DL5DBM

A PDF presentation about Amateur Radio and Linux by By: Dave Mamanakis. A beginners guide to Linux for radio amateurs, this presentation cover basic concepts of the open source operative system, from the basic installation to the setup of ham radio programs.

The Resonant Feedline Dipole (RFD) HF antenna design utilizes a single piece of coaxial cable and a stranded wire section, forming a 1/4-wavelength radiator. This configuration, based on a 1997 ARRL Handbook design (page 20.17), functions by RF traveling on the inside of the coax shield and returning on the outside, creating the second half of the dipole. A choke wound into the feedline prevents RF current from flowing back down the feedline. Construction details include using RG-58a/u coax for a 75m version, with a 1/4-wavelength section of stranded wire soldered to the center conductor. The document provides choke dimensions for RG-213, RG-8, and RG-58 coax across 3.5 MHz to 28 MHz, specifying cable length and number of turns. Dipole dimensions are also tabulated for frequencies from 3.6 MHz to 28.4 MHz, listing overall length and individual leg lengths. Field tests included deployment near Bryson City at 5 feet off the ground and as a sloper during WCARS Field Day in Asheville, yielding successful local and regional contacts.

W3EDP antenna assembly instructions and dimensions with pictures in this PDF File

An home made vertical dipole antenna made with simple material. The antenna has a total length of aproximately 16 feet. In this article appeared on June QST 2019, the author explain how he reached the optimal confirugation changing and adjusting the lower part of the antenna, trimming and spacing correctly the copper wire. PDF File to downloas

ARRL Laboratory Expanded Test-Result Report Kenwood TS-570D

CO2KK exposes some myths about using 75-ohm feedline with 50-ohm rigs and show how to build a cotanget transformer

A scanned PDF of this interesting book on HF Dipole antennas published by Stanford Research Institute

Cushcraft X7 20-15-10 Meter 7 element beam Assembly & Installation

A proven and practical approach to dealing with RFI from grow lights and more.

Ebook by Akira Matsuzawa Tokyo Institute of Technology, Building blocks in RF system and basic performances, Device characteristics in RF application , Low noise amplifier design, Mixer design and Oscillator design

Hidden transmitter hunting, often called fox hunting or Amateur Radio Direction Finding (_ARDF_), presents a unique challenge for radio amateurs. This resource details the _PicCon_ controller, a specialized device designed to automate the transmission of signals for such events. It integrates with a standard radio transceiver, functioning similarly to a packet radio TNC, by controlling the Push-To-Talk (PTT) line and injecting audio tones or modulated CW Morse code into the microphone input. The _PicCon_ unit is field-programmable using DTMF tones received via the radio, storing all settings in EEPROM for power-off retention. Its compact design and low power consumption (a few milliamps from a 7-35VDC source) make it suitable for remote deployment. An onboard LED indicates operational status, and a push-button allows manual start/stop of transmissions without DTMF. Typically supplied as a kit, _PicCon_ includes a PCB, components, and a comprehensive manual (available in HTML, RTF, and PDF formats). The kit provides a six-conductor interface cable, but users must supply radio and power plugs due to varied configurations. Byon, _N6BG_, developed this controller, which is available from the Byonics website.

A project of a 5 Antennas Relay Switch Box, all Switches & Relays have both contacts wired in parallel to improve reliability of operation, to prevent static build up, when an antenna is not in use the feeder coax is grounded.

6-Meter Solid-State 100W Linear Amplifier complete documentation German and English

For those who are interested in telegraphy, for those who would like to learn it, for those who love it, and for those who want to improve their skills in it

A Loop Fed Array Yagi antenna for 50 MHz featuring 11 dBi gain and 23 f/b ratio. In this excellent page the author even includes a detailed drawing in DWG format, with element lenght and spacing measures, in a separa file a full list of material list needed to build this yagi antenna including source and price, the EZnec file for this antenna plan, and a lot of pictures of this LFA Yagi for 50 Mhz. A ten page PDF file containing all infos, is also available to download.

Resonant Feedline Dipoles for 4m and 2m

A practical approach to microwave signal analysis for the home experimenter

An optimized QRP transceiver for 40 meters band

Manuals of butternut antennas

Nino porcino documentation about CHIP64 digital mode

Operating an 80/40/20M fan dipole for DX is analyzed through EZNEC modeling, focusing on the antenna's performance in a real-world, low-height installation. The resource details the physical construction and SWR measurements of the fan dipole, comparing them against EZNEC simulations. It also incorporates High Frequency Terrain Analysis (HFTA) data to illustrate typical DX elevation angles for various regions from New England, providing a crucial context for evaluating antenna patterns. The analysis presents EZNEC-generated azimuth and elevation patterns for each band (80M, 40M, 20M) at specific frequencies, showing gain figures at different elevation angles relevant to DX propagation. It compares the modeled SWR with measured SWR, attributing discrepancies to coax attenuation. The study concludes with observations on the antenna's azimuth performance (omnidirectional within ±1.5 dB) and its less optimal elevation gain at desired DX angles, highlighting the impact of low antenna height on DX capabilities.

An Experimental, High-efficiency, Graphic-Tunable Magnetic Loop antenna and loop controller in a 52 pages PDF presentation with drawings and pictures

A 5/8 wave antenna, can be fed with ladder line from the center insulator to tuner.

Istructions to use the IFD demodulator

QST review for Yaesu FT-920

Green that aluminum into something useful right in your own backyard by WB2CQM