direction finding circui

G0KSC Revolutionary Yagi Antenna Feed System - New feed system for the Yagi directional beam antenna, that suppress unwanted side lobes within longer Yagi designs by G0KSC

A 144 MHz Halo - This halo antenna was built to have an omnidirectional coverage while working in VHF contests. The idea was to have a small but useful antenna for receiving, but it has demonstrated very capable on TX also.

DF Antenna for 2 meters - Direction Finding (DF or Fox) hunts antenna for 144 Mhz

Weatherproof Vertical Antennas - Slim Jim - How to make a Weatherproof Vertically Polarised Omnidirectional Aerial, The Slim Jim Antenna

Build an antenna for 23 cm band - Building an omnidirectionnal antenna for the 23 cm band, 1240 - 1270 Mhz

Uni-Directional WIFI Range Extender - Requires no modifications to a USB WIFI adaptor or your computer.

QHtenna - The QHtenna Turnstyle antenna system offers horizontal omni-directional antennas for the Ham frequencies in the VHF/UHF range of 50 Mhz to 432 Mhz. The Crossed Field Antenna" (CFA) by QHtenna offers a small antenna for limited space, maritime mobile, and seasonal DX work.

Wire Harness Assemblies - Printed Circuit Board, Custom Overmold Cable Assembly, Box Build, System Integration, Sheet Metal

Doppler Systems - Radio Direction Finding products

KE6HTS ARDF products - RDF - Amateur Radio Direction Finding

Radio Frequency Beacon Finder - This project is a radio frequency receiver that will help the user the trace the direction and distance of transmitter beacon(s) operating at 433MHz frequency by Cornell Univerity

Radio Direction Finding - introduction - History of Radio Direction Finding, performance and limitation of RDF Systems, RDF for non professional use

Broadcast Books - Directional Antennas Made Simple The "How To" Book by Jack Layton

IC-746PRO TX Problem - The IC-746PRO is a great rig. But it has a few reliability issues, especially with the earlier-production units. This article addresses four problem areas:. IC151 on the RF Unit. Driver circuit on the PA Unit. HRX-muting circuit on the CTRL Unit. Predriver on the PA Unit.

5Spice - Analog circuit simulation program for the typical circuit designer. Commercial version for windows

NL5 Circuit Simulator - Analog circuit simulator for Windows (not a SPICE). A great tool for students, amateurs, as well as for experienced engineers. Free Demo.

Enable Low Cost RF Power Amplifiers - A new paradigm for low cost, reliable RF amplifier ‘pallets’ has been enabled by new circuit design, manufacturing and thermal management techniques

Power Aamps RF voltages - This test circuit is easy to duplicate, and demonstrates the extreme voltages that appear in an amplifier when the load is improper for the amount of drive power applied.

Build a Remote Control Antenna Switch - Remote Control Antenna Switch made with two circuits board

A fool-proof VOX - A circuit which had been used in many other application before. The configuration described here is optimized for IPHONE/radio operation.

KI5YN QLF Filter - A microprocessor based interface designed to go between a standard Morse code key and a radio transmitter. The circuit receives a signal from the key, processes it, and re-transmits it to the radio.

QRP AM(cw) Transmitter for 10 meters - In this project, you will make a simple low-power broadcast-type circuit, using a crystal oscillator integrated circuit and an a collector modulated AM oscillator.

Lightning Protection : Protecting each I/O line - KB22UT Article on how protecting ham radio station and in particular I/O Lines such as AC power, coax cable, control circuits, telephone line.

Sound Card interface - Interface to insulate the radio circuits from the computer by VK2GWK

Using An Oscilloscope - It allows you to take a peek into a circuit to see what is happening has it happens, irrespective of the speed with which it is taking place