Tuner Baluns on Input
- There is a common perception that placing a balun on the input of a tuner causes the balun to work better. The thought is the balun operates with a matched impedance and that reduces balun losses. It also is thought that moving the balun improves balance.
Two wire broadband HF dipole
- This article describes the design and simulation of a two wire broadband dipole antenna for the HF band, using the software 4Nec2. The antenna is designed to operate in the full range 3-30 MHz
9L5MS Sierra Leone
- In close cooporation between the DAGOE Foundation, Mercy Ships, 4 Dutch and 1 Liberian radio amateur will run a Radio Project from Sierra Leone. We will be on-site in Freetown between March 15th and April 4th using the amateur radio callsign 9L5MS.
- Spek helps to analyse your audio files by showing their spectrogram.
Spek supports all popular lossy and lossless audio file formats. Spek is free software available for Unix, Windows and Mac OS X.
Homemade Antenna Rotator Controller
- The Antenna Rotator Controller is unique in that it senses, displays, and controls to the earth’s true magnetic field. The compass sensor, mounted in a waterproof enclosure, is attached to the mast and sends its signal to a microcontroller. By kg4jjh
Bandpass Filters for Portable Usage
- These are QRP rated 3 Pole Butterworth filters based on a design by K4VX, feature simplicity, almost no insertion loss, and reasonable rejection on the other ham bands.