SDR(Software Defined Radio) is the convergence of recent emerging technologies where Radio
Communication modulation, and de-modulation techniques are defined in software, using DSP(Digital
Signal processing) methods. In its simplest form SDR uses a PC soundcard to process signals using
DSP from/to a Tayloe detector/modulator. The out-board Tayloe circuit is nothing more than a
hand-full of digital, as well as analogue components, which are used to up-convert/down-convert
from AF signals to RF signals, and from RF signals to AF signals. The result of the two working
together produces a power-ful SDR RX or TX which matches the best conventional Direct Conversion or
At the moment I am looking at the SoftRock line of SDR radios for projects. I am considering using SDR principles, combined with DDS(Direct Digital Synthesis) to construct a multi-band HF RX.