data transmission

How to Make a Great 9:1 RX Transformer - There are lots of good designs for matching transformers for receiving antennas. Make it yourself it's cheap and easy, and very high performance. This is the design used in the TRX-9 transformers.

From Transmitter to Antenna - A collection of articles on the subject of impedance, impedance matching and high-frequency power transmission by G3YNH

Beverages on 40 Meters - Gary Breed, K9AY experience with beverages on 40 meters

The Off-Center-Fed Dipole - A Broadband, Multiband Antenna taken from QST, Aug 1990. OCF Dipole antenna.

Matching Waves, VSWR at work - When the radiation resistance (voltage to current ratio) of an antenna is the same value as the characteristic impedance of the transmission line (voltage to current ratio in the line), all of the electrical energy transmitted down the line is taken by the antenna and radiated into space in the form of a radio wave.

Single-stub matching - Single-stub matching of transmission lines to loads A worked example

Ham Radio Contest Maps - US Contesters maps generated based on ARRL online score data by WM5R

Beacon List Generator - Ham Radio Beacon list generator from SK6YH database

Numbers Stations - About numbers stations, and their criptic transmissions, where to listen to them and some audio recording samples by fascinating shortwaves

Argent Data Systems - OpenTracker+ and Tracker2 series APRS devices for real-time vehicle tracking, weather monitoring, and remote telemetry, aprs tracker manufacturer.

Timewave - Sells leading-edge voice and digital communications products to the world-wide military, government, industrial, and amateur radio marketplaces. Bluetooth Remote Audio/PTT, Rig Controller with Audio & PTT , HamLinkUSB Rig Control, Noise filtersm antenna analyzers, Multimode Data Controller, TNC, Packet Radio Terminal Node Controller. USB2RS232

Google and APRS - N6BG site using google maps api to show APRS data

Digital Amateur Television - First Amateur DVB transmissions in Finland !

TH-D7 Data communicator - Kenwood TH-D7 details. Kenwood's new TH-D7e is equipped with a TNC and provides a wide range of data communications options

TH-D7E modifications - Extending reception and transmission of a Kenwood TH-D7, upgrading firmware, enabling the SKY-COMMAND

Frequenzdatenbank.de - Frequency database for Germany. Emergency services, aircrafts, radio and paging system with over 2000 frequencies from all over Germany.

4ATV.com - Amateur TV transmitters and receivers for ham operators, wireless cameras, ham antennas, 2.4 1.2 900 Mhz systems

Super Check Partial - Super check partial is a feature that K1EA first introduced in his CT logging software. It enables the use of a database to extend the list of calls that appear in the check partial call window. Used correctly, it can help you more quickly pull a call out of the QRM

Miltimonitor - Linux Radio Transmission Decoder support AX.25 POCSAG DTMF ZVEI by Thomas Sailer, HB9JNX/AE4WA

linsmith - A Linux Smith charting program. You can enter either discrete components or transmission lines, see the results on screen and/or generate Postscript output. Component values can be changed numerically or using scrollbar

ALL2DTA - Win32 command line utility, that allows you to create Master Callsign Database file (DTA), used in many contesting programs, from different logs in ADIF, Cabrillo, and plain text formats.

Attenuators and Preamps - How to get the most from attenuators and preamps

A 25 Watt Dummy Load - Dummy load described here can be used for up to 35 watts for short transmissions, and up to 25 watts for longer periods.

Interface for TM255 and TM455 - PTT and souncard interface for the kenwood TM255 and TM455

N2PK Vector Network Analyzer - Homebrew VNA capable of both transmission and reflection measurements from 0.05 to 60 MHz