Bits & Pieces

Helmholtz Coil

The basics about Helmholtz coils: Basic physics, applications and formulas. Interactive online calculator to aid in designing a simple two coil Helmholtz cage.


The basics about HDLC and AX.25 frames, how they are composed and assembled. Interactive online AX.25/HDLC frame generator (encoder and decoder).


A very versatile and configurable Sub-GHz transceiver. Operates from 27 MHz to 1050 MHz. Offers multitude of different modulations like (G)FSK, (G)MSK, AFSK, PSK, ASK and FM, with datarate up to 125 kbps.


An explanation on what is AFSK, how it works and for what it is used. Showcase of a digital implementation using Scilab of both modulation and demodulation. This includes FM modulation/demodulation, Audio-FSK modulation/demodulation and emphasis filter.