security alarm circuit

Guanella 4:1 balun - This article reviews the proposition that a 4:1 current balun in the style of Guanella can be constructed with both pairs of windings sharing a common magnetic circuit.

WB2HOL Foxhunting beam - Building the WB2HOL foxhunting beam antenna

San Diego Radio Emergency Communications - San Diego REMCOM volunteer group specializes in serving the county and hospitals during drills and disasters. All members are FCC licensed radio responders, certified in ICS training, have passed security background checks with signed confidentiality statements.

VU2UKR HAM Radio Station - HAM Radio India Yagi Beam CW QRP SSB QUAD DX circuits sound card Transceiver Morse HF VHF Antenna Satellites Amateur Club Station Operators Licence Exam ASOC Guide Digital Mode Equipment Transmitter Experiments Project schematics Beacon dx HAMSAT VUSAT Satellite Emergency communication Information Homebrew QRP Kits

Huston Fire dispatch - Listen live to Huston Fire Dispatch

Advanced Linear Devices - Electronic compoenents manufacturer of precision CMOS analog integrated circuits for OEMs of industrial controls, computers, instrumentation, automotive, and telecom. Transistor mosfet.

Kenwood TS-50 IF-10D interface - Circuit of the Kenwood IF-10D interface for the TS-50 transceiver.

Mini Circuits - RF / IF Microwave components DC to 20 GHz

IC-Prog Prototype Programmer - PIC Programmer software package that allows you to program all types of serial programmable Integrated Circuits using Windows 95/98/NT/2000/ME/XP

Ansoft Designer - Sesign-management environment and circuit simulator for radio frequency (RF) and microwave hardware development

IC-Prog Prototype Programmer - This software package allows you to program all types of serial programmable Integrated Circuits using Windows 95/98/NT/2000/ME/XP

Increasing Amplifier Relay Speed - Article describes a circuit that accelerates the coil of DC relays by momentarily doubling their voltage.

Transistor Audio Preamplifier Circuits - Design Guidelines for Bipolar Transistor Audio Preamplifier Circuits By Mike Martell N1HFX

VersaBeacon Project - The VersaBeacon is a frequency agile, modulation agile RF source using a DDS chip and minimal support circuitry. It covers a frequency span of 1MHz to 150MHz in 1 Hz steps and provides a variety of modulations

Resonant Frequency Calculator - This web based application will compute circuit values required for an L-C circuit to resonate at given frequency. Also it will compute the resonant frequency if given values for L and C.

Frequency Counter project  ^updated - Circuit and construction instruction designed by Mani VU2ITI

A simple iambic keyer - Iambic keyer with simple paddles and simple electronic circuit.

M3 Electronix Semiconductor Analyzer Kit - A workbench instrument capable of testing transistors, diodes, FETs, usefull constructing QRP circuitry.

QRP AM CW transmitter - A simple low-power broadcast-type circuit, using a crystal oscillator integrated circuit and an a collector modulated AM oscillator

CAT programming interface for ICOM rigs - This simple and cost effective interface circuit is designed for use with any ICOM amateur radio equipment with CIV interface

Kenwood-to-PC Serial Interface - A circuit that connects an IBM® compatible personal computer, running TR Log or CT (etc.) contest logging software, and Kenwood transceivers equipped with serial control ports. CW keying is also provided in this RFI filtered interface unit.

NB6M 10 Homebrew Receiver and Keying - Schematic of a homebrew receiver and keying

Regenerative circuit - Wikipedia page about regenerative circuits in designing receivers.

A Bipolar Regenerative Receiver - Contrary to what some radio experimenters think, a bipolar regenerative design can be made to work efficiently

The Modern Armstrong Regenerative Receiver - Ramon Vargas Patron articel on regenerative receiver project