direction finding circui

2 Meter 10 Element Quagi Antenna - This antenna was designed by N6JSX Kuby for Transmitter hiding. Fitting the requirements of directionality, high gain, and portability. This antenna was derived from the ARRL Handbook information on Quagi's and Yagi's; in the absence of two meter Quagi information, UHF Quagi dimensions were scaled into 146 MHz use.

Shorty Forty Antenna - Short dipole antenna for 40 meter ham band. Can be put up in the space required for a 20 meter dipole.

The EH Antenna analyzed - This report is a recent analysis of the EH antenna using the Pspice program and considering the antenna as a set of circuit elements

Common Mode Choke Theory - A common mode choke may be used to reduce a type of electrical noise known as common mode noise. Electro-magnetic interference (E.M.I.) in the circuit's environment is one source of electrical noise.

The full-wave loop antenna - These omnidirectional antennas offer Horizontal polarization, and about 2.1 dbd of gain. They are much quieter than a dipole or a vertical, have a broader bandwidth and will usually out perform a dipole antenna.

A homebrew 10-element 900 MHz quagi - A 10 elements quagi antenna for 900 mhz

Optimizing Inductors - While intended mainly for antenna loading coils, this article also applies to other resonant systems, such as amplifier tank circuits.

DirectionalBiQuad - Seattle Wireless - A biquad is a fairly powerful antenna which is relatively easy to construct, with impressive performance for their size. A link greater than 5 miles can be made with a pair of these as a stand-alone antenna and a Prism2 100mW card, provided you keep coax short, and your line-of-sight is clear.

Peet Bros Company - Manufacturer of advanced electronic systems to measure such weather data as: wind speed, wind direction, wind chill, pressure, humidity, rainfall, and dew point.

SSB Electronic USA - manufactures and distributes HF, VHF, UHF and SHF equipment covering 10MHz. - 47.0GHz. Our products include: Wireless LAN / WAN Bidirectional Linear Amplifiers, Low Noise Preamplifiers - LNA's, RF Linear Amplifiers, Relays, Transverter Systems, Frequency Translation Systems, Downconverters, Antennas, Parabolic Dishes, Coaxial Cable, Relays, Antenna Switches, Microwave Test equipment, PC controlled Receivers, Microwave Linear Amplifiers including models for Telemetry, Wireless, and CDMA applications.

Communication Concepts, Inc. - Provide components to the amateur who wants to construct their own gear and to the professional who wants to save money and time in prototyping their circuit design, Filters, HF Amplifiers, Splitter Combiners, VHF Amplifiers, ATV

Intuitive Circuits, LLC. - Intuitive circuit llc is a market leader in dtmf encoders and decoders, cash register surveillance, cash register security, and text inserter products. Amateur televisions ATV products

Eliminate QRM from 6 meters band - The circuit described below will substantially reduce or completely eliminate interference from almost any local source whilst leaving the wanted signal relatively unaffected, even though it may be on the same frequencey by TREVOR, G3ZYY

All American - Distributor of electronic components, ull range of semiconductors (active components), including relays, circuit breakers, transistors, diodes, memory devices, microprocessors, microcontrollers, and other integrated cuircuits, as well as passive components, such as capacitors, resistors, inductors, and electromechanical products, including cable, switches, connectors, filters, and sockets.

Circuit Specialists - We specialize in pc-based data acquisition systems, test equipment, electronic components, disk on modules, choke and coils, diodes, capacitors and connectors, potentiometers, crystals, resistors, relays

HL1INF RF Amplifiers - Circuits, pictures and data about toroids, tubes and home made power amplifiers

DL5DBM 1KW amplifier for 144 Mhz - Pictures and circuit diagramm to build this power amplifier for 2 meters

Build An Audio Speech Processor - When one operates at low power on SSB, speech processing becomes almost essential to get through the QRM. The circuit is a low cost speech processor that will perform well with a minimum of construction effort.

Constant Current Battery Charger - Constant Current Battery Charger circuit project

DigChip IC database - Provider of electronic components documentation. Offer a reliable tool to find semiconductors components technical information like parts, datasheets, cross reference, obsolete and new circuits.

5 Watt 40 Meters transmitter - This circuit is unique in that it uses a power mosfet as a final rather than a conventional bipolar transistor.

Build a Vox Circuit - by Mike Martell N1HFX

Simple Electronic Keyer - A simple keyer which can be built for as little as $6 with some junk box parts. Although this circuit is not a true iambic keyer, it is capable of producing perfectly sounding CW.

Easy Morse Code Keyer Circuit - based on the famous Curtis family of morse keyer chips and has a proven record of dependability.

50MHz-Transverter 10m/6m from DK7ZB - This transverter was built in 1994, a discription in three parts (german language) for DOWNLOAD as PDF-files. Circuit, printed-boards and layouts in the files