battery circuits

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

NM-ARTS - Amateur Radio Technical Society - A hardware and software project group to support learning and creation radio circuits, general electronics, and uProcessor control systems

Jackson Harbor Press Kits - Ham Radio Kits, morse keyers, Morse code voltmeter / DC switch / battery saver

BK Precision - Power supplies, electrical testers, battery analyzers, cable tester, rf generators, spectrum analyzers, Digital/Analog Oscilloscopes, Multimeters , attenuators, frequency counter

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

Is HF propagation reciprocal - Some test circuits using the ACE-HF System Simulation & Visualization software, about reciprocal propagation on HF bands by NW7US

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

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.

AP Circuits - Printed circuit board fabrication

Malux - El-Tele-Data - Accessories, Antennas and Battery chargers. Radiators, Repeaters, Yagi, Mag, Car, Tetra, Marine, Multiband, Brackets, Mounting accessories, cables and connectors, radiokits, special cables etc. Based in Finland

ScopePar - ScopePar turns your old PC into a multi-channel oscilloscope, the user-interface to which is SeriCon on Windows PC.

Solar Panel Charger Project - A flexible, foldable, and durable solar product that produces enough power to charge your Battery Pack quickly

AA Battery Solar Charger - This almost trivial circuit may be used to charge a pair of AA or AAA sized rechargeable battery cells from sunlight.

Free Sun Power - Free basic and advanced system design tutorials for every component and aspect of solar power. Plus system sizing calculators, battery bank calculators and wire size calculators

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

Build a Remote Control Antenna Switch - Remote Control Antenna Switch made with two circuits board

Batteries and QRP - Thanks to the popularity of cell phones, laptops and other personal electronic devices, the battery industry has been market-driven to produce higher capacity batteries in lighter weights than previously possible with yesterday's chemistries.As a result, a wide variety of battery types are available to the outdoor QRP operator.

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

Economical keyer - Using the PicoKeyer chip. Features a 60 character memory, setup & message entry using a paddle and no battery is required to retain the memory.

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.

20 Amp power supply - A 13.8 volt 20 Ampere power supply project

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

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

Fun With Tubes - Dedicated to passing on and preserving knowledge of vacuum tube circuits and techniques