circuit design

6 element UHF Yagi antenna - A standard 6 elements design scaled for UHF application. All material used in this project are easily obtainable tubes and rods which is limited within a total budget of $18.

80 Meter Pizza Pan Antenna - This is a resonant, half-wave, vertical antenna. It takes up little space in the back yard, was designed for operation on a single frequency 80 meter PSK net, and is reasonably inexpensive to construct by Chuck Hines, K6QKL

RF Balun Transformers - This application note is designed to help the reader understand how balun transformers can be used in today’s RF/Microwave communication applications.

HF Antenna Switch - The purpose of this remote antenna switch was to be able to select between four different antenna combinations The unit was designed to work at RF power levels of around 100 watts by G8JNJ

Homebrew Pac-15 Vertical - This page shows a homebrew vertical antenna based on the Pac-12 antenna design.

VHF/UHF Folded Diplole - This is a two element colinear design for vertically polarized radiation. It may be constructed for use on either 2m or 70cm

Sidemount VHF/UHF Antenna - This antenna is designed to be mounted off the side of a tower. Works on 136-153 Mhz range but also on 70 cm band

Yagi-Uda Antenna Priority listing - The Yagi-Uda antenna, information on basic design, project and measure of Yagi-Uda antenna, include free repository/sample of beam antenna.

DICL - Customized Power Supply - Design and manufacture switching power supply for global customers in many field , such as industry , medical , radio , telecome

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.

K7BON - Callsigns in Oak - Your call sign, name or specialty item professionally crafted in oak (two thicknesses available), from a computer designed pattern and finished in up to 4 coats of Formby's Glossy Tung Oil.

M.C. Howard Electronics - Distributor of Common Electronic Components Such As Memory, Integrated Circuits, Discrete Components, Cables And Services. We Also Provide Prom Programming, Simm Manufacturing, Testing And Custom Kitting.

DERF electronics corporation - Distributor of electronic components like diodes Transistors Microcontrollers Microprocessors connectors, switches, relays, integrated circuits, eproms, leds

AP Circuits - Printed circuit board fabrication

cocoaNEC - cocoaNEC 2.0 is an opensource Mac OS X application intended primarily for the design and modeling of antennas by Kok Chen, W7AY

Panel and Dial - Freeware windows and linux tools to design front panels and dials labels for your home-brew projects.

AADE Filter Design - Freeware windows programs to design Butterworth, Chebyshev, Elliptic (Caur), Bessel, Legendre and Linear Phase low-pass, high-pass, band-Pass, and band-reject filters. Coupled Resonator band-pass filters

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.

Design RF Filter

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.

Power Supply Design - A home learning tutorial on the basics of designing simple power supplies for radio projects by VK2TIP

HV power supplies - WV0NNI 2,800 VDC @ 2 Amps Continuous Variac adjusts filament voltage. A voltage doubler circuit, well suited for smaller, compact linear amplifiers.

Designing Op Amp Audio PreAmplifiers - Design guidelines for Op Amp audio preamplifier circuits by Mike Martell N1HFX

How to desolder components - Learn how to correctly desolder electronic components from printed circuit boards

How to solder - Key facts about how to solder, how to solder wire, how to solder pcb's, and including general soldering techniques and the best ways of making good solder joints for electronic circuits and construction. Includes video