spectrum circuit

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.

USA frequency allocations - The radio spectrum in usa, PDF File representing the united stares frequency allocations in graphical mode, by NTIA

WiNRADiO Communications - WiNRADiO Communications manufacture radio communications equipment for a very wide range of applications. Our customers include professional communications radio users in government, military, security, surveillance, spectrum monitoring organizations, telecommunications, industry, as well as radio and computer enthusiasts.

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

Expanded Spectrum Systems - Flash crystals, Feakin' beacon keyer, beacon attenuator

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

Sunstone Circuits Priority listing - Sunstone Circuits is your easiest source for quoting and ordering printed circuit boards online. We are three respected brands in one: PCBexpress quickturn boards, PCBpro.com full-featured and design-checked boards, and PCB123 design software.

Canada, radio spectrum allocations - Graphical maps of radio spectrum and frequency allocations in canada

Antenna Noise and Signal Cancelling at LF - The fact that the phasing between a wanted signal and an unwanted signal can be different on different antennas is put to advantage. With this condition, the unwanted signal can be cancelled out by controlling amplitude and phase. The heart of the system is some form of phase control circuitry.

Longwave operations - In the VLF portion of the spectrum it is easy to listen to the emissions created by the Earth itself. These emissions are generated by many different mechanisms and are often beautiful to listen to. Coverage on LF and MF frequencies

Far circuits - Direction finding projects, useful tools for t-hunting operations

HRX80 80 meters receivers for APRS - 80-meter peilontvanger / receiver includes printed circuit sample and list of components

HF Radio wave propagation - Radiowave propagation in the medium and high frequency spectrum in DOC format

Qsk keying for yaesu radios - QSK amplifier keying circuit for Yaesu FT-1000MP, FT-1000MP Mk-V, FT-1000/1000D and FT-920

FM transmitter kit for 88-108 Mhz - 3 Watt fm Transmitter Hobby Kit 88 - 108 Mhz. Kit Includes Glass Fibre Printed Circuit Broad High Quality Componets Full Instructions

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

Baudline signal analyzer - A Linux based FFT spectrum analyzer designed for time-frequency browsing and scientific data visualization. Oscilloscope waveform, statistical histogram, accumulated spectral trace,Weak Signal reception, continuos data logging, FFT Analyzer and specialized measurement windows.

Constant Current Battery Charger - Constant Current Battery Charger circuit project

RF Coaxial Connectors - RF coax(ial) connectors are a vital link in the radio spectrum. Coax connectors are often used to interface two units such as the antenna to a transmission line, a receiver or a transmitter. The proper choice of a coax connector will facilitate this interface.

Delabs technologies Product Design and Engineering - Around 200 electronic circuits in pdf format or images, There are also over 1000 links to useful electronics, freeware, open source websites. There are some 100 useful documents, software and pcbs too. Mainly industrial electronics, instrumentation. Covers Various aspects of electronics and basics of circuit design.

Making printed circuits - To make smart looking PCB's, all you need is a computer, a laser printer, copper clad board, etchant, a clothes iron and some Epson glossy photo paper.

A low pass filter circuit - A simple 7 element, Chebyshev low pass filter, rolls of at 30MHz. Attenuation is better than -40dB at 60MHz, -65dB at 90MHz, -80dB at 120MHz.

Bowden's Hobby Circuits - A small collection of electronic circuits for the hobbyist or student. Site includes over 100 circuit diagrams, links to related sites, commercial kits and projects, newsgroups and educational areas. Most of the circuits can be built with common components available from Radio Shack or salvaged from scrap electronic equipment

A CW TX for 80 meters band - This simple circuit will give about 1.2 Watts of output when powered from a 13.8VDC supply.