direction finding circui

N9ZRT Kite-Lifted Antennas - Kite-lifted wire winch consists of 1/4 mile of 15 gauge, bare, solid, aluminum wire, spooled onto a wide pneumatic hose reel. The base pivot-platform locks into place for changing wind direction.

5 Element yagi for 10 meters - A directional 5 element yagi antenna for 28.5 Mhz in spanish

Directional arrays - About collinear array antennas

Build a hanging dipole for 2 metres - Described here is a simple omni-directional, vertically-polarized dipole for two meters. Made from coaxial cable, it can be rolled up and stored in a small container

The K9AY Terminated Loop - A compact directional receiving antenna

Antentop: Loop Antennas - Article on radiation patterns of small loops, equivalent circuits of loop antenna, small loops as receiving antennas, ferrite loops

Loop antenna for NDBs - Nondirectional Radio Beacons, NDBs, can easily by received with this loop. Resonant in the 200 – 500kHz range, the loop antenna is directional, sensitive, and quiet.

Remotely-tuned loop antenna for LW and MW - This article describes how to build a loop antenna for low frequency (LF) and medium wave (MW) reception with remote-controlled tuning. The antenna is extremely sensitive and can be built mostly from parts from old radios and tape recorders. Like all loop antennas, it is highly directional, which allows you to null out unwanted noise sources.

Sensitivity of Multi Turn Receiving Loops - Magnetism is manifested as a 'field of vectors', that is, any point in the magnetic field has not only a magnitude, but a direction in space. The four Maxwell equations describe how electric and magnetic vector fields behave and interact.

Corner reflector antenna - Do you need a high gain antenna? Have you suffered on picking up interference from unwanted direction? You need a directional antenna but a 12 element Yagi will be too attractive!

Building Coaxial Traps - This page describes the design and construction materials W8WWV used to build a coaxial cable trap. A coaxial cable trap is a parallel resonant circuit that is usually inserted in an antenna element to enable multiband operation.

Multi Band Antenna Traps - These devices are called Traps, but they are actually more like frequency sensitive switches. They are parallel resonant, high Q, tuned circuits which provide a very high impedance at their frequency of resonance.

Common vhf amateur radio antennas - Plans and drawings of common amateur radio antennas, like jpoles, copper cactus, super jpole, omnidirectionals and quads

Canadian Antique Radios Schematics Diagrams Service - We specialize in canadian antique radio schematics for vintage tube radios made in canada. we carry lots of factory electronic circuit schematic diagrams as well as all rcc / radio college of canada service data 1920's - 70's.

PSK31 Interfacing - PSK31 basics and radio to pc soundcard interface circuits, radio to soundcard, soundcard to radio and pc serial port to radio

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

ExpressPCB - Free PCB software is a snap to learn and use. For the first time, designing circuit boards is simple for the beginner and efficient for the professional.

PreMuLoc for windows - This program combines the formerly know programs PreFind and MU-Locator into one but with many improvements to find the location of any prefix, country or Maidenhead locator! Display and find locators on any map and calculate the distance and direction between two locators.

AM-6154 FAA Amplifier circuit conversion - AM-6154 222MHz grid Conversion Information by N0UK

Medium Frequency Amplifier Circuits Compared - Mark Connelly, WA1ION article on Medium Frequency Amplifier Circuits in PDF format, include some RF amplifier schematics

Rotator Brake Delay and Protection Circuit - A rotator modification by W4ZT

Offset Attenuator for Radio Direction Finding - Instead of acting directly on the incoming signal, an offset attenuator works by adjusting the strength of an offset signal

NiCad battery charger - A basic nicad battery charger using a single medium power transistor.

A Power Supply on the Cheap - Need a variable power supply that is short circuit protected and over voltage protected; Here is a good one that can be built cheap by VE3IVJ

Universal QRP Transmitter - Here's the homebrew Universal QRP transmitter adapted from work by Wes Hayward - W7ZOI. The circuit originally appeared in QRP Classics published in 1980 by the ARRL