Category: Telecommunications

Introduction Joe Taylor K1JT came out with a ground breaking paper in the December 2001 issue of the ARRL magazine QST (Reference 1). He described a new digital modulation scheme “WSJT” (Weak Signal Communication by Joe Taylor) using a 4FSK modem that was designed to perform well over 6m & 2m amateur radio meteor scatter… Continue reading WSJT FSK441 Modem – Scicos Simulation

ScicosLab/Scicos is an Open Source Math Program that can be used in various engineering and scientific applications. In this post I look at how an AM Modulator can be built using the Editor in ScicosLab and also with the visual block Editor Scicos with the Modnum Toolbox. Video ScicosLab/Scicos – AM Modulator Download “Learn Telecommunications… Continue reading ScicosLab & Scicos – AM Modulator

In a previous post Ref.1 I looked at VOACAP and it’s use in a simple off air receive situation. In this post I will delve a little further into the software and compare the results against some simple mathematical models. VOACAP (Voice of America Coverage Analysis Program) is free professional high-frequency (HF) propagation prediction software… Continue reading VOACAP – CHU to VE3PKC+

VOACAP (Voice of America Coverage Analysis Program) is free professional high-frequency (HF) propagation prediction software from NTIA/ITS, originally developed for Voice of America (VOA). In this video we will study the propagation between the time signal station CHU located in Ottawa Canada with a receiver located at VE3PKC in Toronto Canada. The actual received signal… Continue reading VOACAP – CHU to VE3PKC

Introduction The unit impulse or Dirac Delta function δ(t) is an essential building block of modern telecommunications, similar in importance to the FFT that was examined in the previous post. The function came about as a result of research done by the British Physicist Paul Dirac on the modelling of a point charge (Ref.1). It… Continue reading Dirac Delta Function – δ(t)