circuit design

KN4LF Antennas - Antenna design and LW, MW, SW and Amateur Radio dx'ing.

50 MHz Antennas by DF9CY (4 & 6 Element)  ^pop - Two well performing 50 MHz antennas designed with W7EL EZNEC along to many other antenna projects and related articles

Reflected W Beam - Hexagonal Wire Beams for 40-10m from DL7IO, different mono/multiband designs with building descriptions and model files for EZNEC

OH2GI Ham System - All-mode contesting and logging software system designed primarily for on-line operation of HF digital and CW radio stations through Terminal Node Controllers (TNC)

Pacific IOTA Numbers - IOTA Designation for The Hawaiian Islands

Matt's Media Network - 5 Webcams, SWL info, Top 100 shortwave sites, Webcam Mania Top 100, Matt's Banner Exchange.

SuperCircuits - ATV accessories manufacturer

Signal Engineering - Signal Engineering technologically advanced antennas with modern design and construction technique. Up to date information about current line of high performance 10 and 11 meters antennas.

KMA Antennas - KMA Antennas specializes in HF - VHF - UHF Log Periodic Antennas, unique antennas for the Six Meter band and custom antenna designs.

Q-PAR Microwave Antennas - The company (founded in 1973) excels in the research, design, development and manufacture of microwave antenna systems & components. Our range includes horn, reflector, sinuous, spiral, LPDA, helical antennas, etc; antenna positioners, and many bespoke components.

Piccon - PicCon is a PIC microcontroller based radio controller designed for hidden transmitter hunting

Valve radios - Viking SW design and produce valve (tube) receivers for the ham and SWL.

Bird Electronic - Design and manufacture of components, instruments and systems for RF power measurement.

Camellia Trophy Shop - Custom Engraved QSLs, Designed On-Line

Elise Software Corporation - Elise Software, OUTPUTMASTER, windows professional software for Printed circuit board, post processor, Gerbers, Drill files, ODB++, files generated fast and simply.

QARTest - Italian only contest logging software, designed for the ARI 40-80 contest.

YPlog - YPLOG logging software for Windows support Icom and Kenwood Radios, map programs and a program for coaxial trap design.

AALog by RZ4AG Priority listing - AALog is a comprehensive logger program designed for amateur radio station operators. QRZ,Buckmaster,Flying Horse lookup, CW/RTTY/PSK31 support, Digital voice processor. DXCC,WAZ,P75P,WAS,JCC,WAJA,WAIP,IOTA,Russia tracking. Many other useful features. eQSL.cc compatible. It look like your paper log and use all power your PC

VHF-DX - VHF-DX for Win95/98 is a VHF/UHF Logging Program specifically designed for 50MHz and above operation.

TrueTTY Priority listing - Program for amateur radio digital communications via a sound card. Supported modes are RTTY (Baudot code), ASCII (7 or 8 bits), PSK31 (BPSK and QPSK) and AMTOR-FEC (SITOR-B, NAVTEX). SELFEC SITOR decoding is possible also. No additional hardware required, need only a sound card. Optionally you can use simple circuit fo PTT-control. Can cooperate with RZ4AG AAlog logger.

Satfax - Satellite weather decoding software, designed for those weather monitors who use their ICOM R7000, ICOM R7100 or AOR 3000A

432 MHz EME PreAmplifier - 432 MHz EME low noise amplifier. Circuit, components and image by Christoph Petermann DF9CY

Tunekit - Filter Tuning Kit for Windows is a electronic filter synthesis program and a practical filter tuning aid for actually designing and building a working filter

Defpom CB and HAM radio mods  ^{updated  pop} - Circuit diagrams, CB and HAM mods, alignments, data sheets and pinouts, a massive site with over 600 pages of free info

50 MHz Transverter idea - Complete 144/50 MHz transverter with GaAs Fet LNA and 400 mW out. No printed circuit board. Schematics and images by Christoph Petermann DF9CY