circuit design

Vertical half-wave aerials for 4m - Practical designs pictures and alternative design of antennas for 70 Mhz by Ross Wilkinson G0WJR

3 Element cubic quad for UHF - Article in spanish with design and descriptio of a 3 elements cubic antenna for UHF

Magnetic Loop antennas - Pictures, designs and answer to common questions on building magnetic loop antennas by ON4CEQ Van Herck

W4JOH Cobra Antenna - The original Cobra antenna, is a multiband 160 or 80 to 10 meter, designed by W4JOH is built using standard insulated wire of about 14 gauge and fed with 450 ohm ladder line down to the shack into a tuner.

Amplitec linear amplifiers - HF VHF UHF amplifiers, designed by hams for hams, and morse keys manufacturer

RF HAMDESIGN - An engineering oriented organization specializing in the design and manufacture of high performance parabolic antennas, 3dB high power RF couplers, Antenna power splitters, directional RF couplers and more items for RF transmission from HF through Microwave frequencies.

Harbour Industries - Harbour Industries, the worldwide High Temperature and High Performance cable manufacturer, offers a wide range of Mil-Spec and Commercial designs such as NEMA HP3/HP4 and SAE AS22759

Neutrik, Connectors - Supplier of professional entertainment connector products. The company designs, manufactures and markets audio, video, fiber optic and industrial connectors

General Cable Home Page - Leader in the development, design, manufacture, marketing and distribution of copper, aluminum and fiber optic wire and cable products for the energy, industrial, specialty and communications markets

Radio Frequency Systems - RFS is a global designer and manufacturer of cable and antenna systems plus active and passive RF conditioning modules, providing total-package solutions for wireless infrastructure.

Motron - DTMF Electronics Manufacturer offers Decoding, Display, Signalling, Data Logging, Remote Monitoring and Control products and design.

Piexx Cunputer and Electronics - Design and build custom electronics for clock enthusiasts, Juke Box collectors and the ham radio community. Produces radio interfaces, and radio upgrades.

NDB Weblog - Many NDB radio enthusiasts publish their reception logs on the web. A completely separate system designed for individual listeners to make their own logs and obtain statistics on NDBs, DGPS and now Navtex Stations they have received. Log listings can be exported in a multitude of formats and then emailed to the NDB List

PI-EL - The Windows program for designing and analyzing PI and PI-L networks by Tonne Software

Elsie - Filter Design - Filter design software. Elsie is an uncommon commercial-grade lumped-element ("L-C") electrical filter design and network analysis program, directed toward the engineer or technician involved in that line of work.

SVC Filter - Filter design software. A program designed to expedite the design and analysis of lowpass (and highpass) filters with nearest 5% component values. SVCfilter is 32-bit Windows electrical filter design software nicely written to help the radio amateur, technician or engineer design and analyze lumped-element lowpass and highpass filters.

Meter - This meter scale drawing program is designed to have a computer do the hard work in making a precision scale for a d'Arsonval analog meter. The resulting scales will typically be nicer-looking than those found on many commercial meters.

Quad - from Tonne Software - This graphics-intensive program designs and analyzes active quadrature ("90-degree") networks for use in SSB transmitters and receivers.

RX-PSK31 - Easy to use Audio Spectrum- and PSK31 decoding program specially designed for SWL's who don't need TX or for anyone who just like to monitor PSK31 or analyse signals. Adjustable DSP and Spectrum settings for audio and frequency spectrum analasys or to set it for best decoding of PSK31 signals. By ON6MU

UISS Windows Packet Program - This program has been designed for packet communication with ISS (International Space Station), PCSat or 'compatible' satellites with ease... Ideal for any UI packet communication.

The KB6IBB Utilities for Palm OS - designed for the ham radio operator or radio scanner hobbyist. It houses four databases that organize your frequency lists. EDACS Trunk - A database that houses the entire EDACS ID table. Conventional - A database that houses lists by channal number. Radio Call Log - A database that allows the user to log calls/notes. Ham Radio Repeaters - A database for ham radio repeaters.

WINRAD by I2PHD  ^{updated  pop} - Winrad is a free software program designed to implement a Software Defined Radio (SDR), meant to run under Windows XP, Windows 2000, or Windows 98SE. In a nutshell, it accepts a chunk of up to 96 kHz coming from a complex mixer in form of two signals, I and Q, fed to the PC sound card.

Diplexer - This program expedites the design of lumped-element diplexers using both the lowpass/highpass and the bandpass/bandstop topologies.

Class E - This program simplifies the design of the single-ended Class E amplifier. Operation is intuitive and encourages "tuning" and exploration.

A simple VOX circuit - Here is a 3 transistors 6 diodes circuit that is a Voice Operated Tx PTT control as well as an ANTI VOX circuit to stop mis-operation from Rx noise by G8MNY