circuit design/14.html

Simple active antenna - This circuit shows an active antenna that can be used for AM, FM, and shortwave

Active HF antenna - An active HF receiving antenna circuit by G7BCJ

LU9DPD Daniel - Homebrew, antenas, balunes, expediciones, circuitos, electrónica, torres, fotos y relatos, todo referente a radioafición, radioaficionados y radioamateur

Antique Radio Schematics  ^updated - Specializes in antique radio schematics, circuit diagrams and service data for vintage tube radios. Carries information for American, Canadian and European antique radios.

Ham Radio India - Gateway to Indian Radio Amateurs. Resource features Indian amateur news, photos, circuits, articles, downloads, message boards and discussion forums.

QRZ.RU Russian HamRadio Server - Free Russian hamradio server special for radiofanats from CIS. Search engine on callsigns, electronic circuits and hamradio programs in www powered with knowledge base.

VLF-LF And the Loop Aerial - The article discusses the theory of loop aerials for receiving and how they reduce the level of local noise. A Loop Aerial is described suitable for use on the LF and VLF bands together with a circuit of an interface loop tuner and preamplifier. The discussion extends to the problems of amplifier noise and the advantages of tuning the loop.

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.

Smith Chart Software - SimSmith is a highly interactive, real time Smith chart graphing program. Circuits are constructed using drag-n-drop. Load files can be imported from the EZNEC and CocoaNEC antenna simulation software and from the AIM4170 and miniVNApro antenna analyzers. Circuits and load files can be of any size. Key Features: SimSmith is one of the few Smith chart packages which models transmission line losses. SimSmith also allows the description of circuit elements using algebraic equations. SimSmith has only one screen and allows the screen to be resized to increase workspace or readability.

Morse Tutor - Morse Tutor is a DOS based program written in C++. It can be used to practice morse code. Various options are available. Morse tutor with Complete Source Code and Binary is available for Download (32KB).

TCube - TCUBE is a combination of a Spectrum Analyzer and a Two Tone Generator, with optional quadrature outputs. It can be used for measuring the intermodulation behavior of an audio circuit, and as a general purpose tool

HAMIC - The Ham Intelligent Calculator - HAMIC, is a program designed to simplify a number of calculations commonly used by HAMs. It is designed for the HAM radio hobbyist, but may be useful to others as well. HAMIC has a simple to use, but powerful graphical interface that allows solving simple circuits such as resistors in series or parallel, or more complex circuits such as L networks or T networks. As well, other calculations such as SWR and reactance conversions are supported. Windows shareware.

Defpom's CB Radio Simulator - It is a application which can be used for troubleshooting CB radio faults, by giving a graphical display of the normal operating frequencies generated by various parts of the CB radios circuits, it can help you identify if a frequency is incorrect or even missing. Another good use for this software is simulating possible frequency expansions, as it allows you to choose any frequency that the PLL is capable of generating, so you can see what the radio will allow you to get !

Audio Preamp - Easy circuit that provide good gain to weak audio signals

OZ2M - Beacon Keyer  ^updated - Circuit and software to build a beacon keyer, includes downloadable packages.

KB2LJJ Radio Mods Database  ^pop - The KB2LJJ radio mods database offers approximately 12,000 Radio Mod's, circuits and manuals.

DigChip IC database - DigChip is a provider of integrated circuits documentation search engine, it's also distributor agent between buyers and distributors excess inventory stock.

Electronic symbols - Analog digital symbols, identification of components, units and conversi¥n tables for electronics circuits design

50MHz frequency counter, V-meter - Circuit schematic PCB and photo documentation on building a 50 Mhz frequency counter

ACWS: Automatic CW Sender by iz7ath - Simple circuit, with a simple push, transmit a memorized Cw messages

Homebrew resources for wireless enthusiasts - PDF resources containing information on low cost ssb,am,cw circuits, which are useful for beginners.

Antenna Noise and Signal Cancelling at LF - By using the signals from two antennas, controlling their relative amplitudes and controlling the phase of one of them, unwanted signal or unwanted noise can be phased out. Circuitry is described which uses the signal from a wire antenna to provide selective cancelling against the signal output from an LF loop antenna.

Regenerative Radio Receiver Circuit - Useful and well thought out regenerative receiver design

WD5HOH Regenerative(Regen) Receiver - This web page describes a small, single tuned circuit regenerative receiver primarily for daylight reception in the 16, 19, 22 and 25 meter international shortwave broadcast bands.

Build A Vector Network Analyzer - The VNA (vector network analyzer) is an essential tool for measuring the complex impedance of a circuit at a given frequency. Article on how to build a Impedance analyzer.