Decoding amplitude-shift keying (ASK/OOK)

Wireless weather stations, car keys, wireless door bells and several other telemetry devices are transmitting their information into the air in the 433 MHz band. The modulation type which is used for these devices is mostly amplitude-shift keying, ASK. The most common ASK form is On-off keying, OOK. The following signal is transmitted each minute […]

SDR – My 433 MHz door bell

Just for some analysis with SDR and for fun I bought a wireless door bell, a Silvercrest model Z31370B. This is a low power 433 MHz device (LPD433).   SDR Sharp Quickly after starting up SDR Sharp, tune-in to the 433 MHz band, and pressing the button of my door bell, I had the following […]

SDR – FM Radio

Today I build my first FM radio. GNU Radio Companion makes the job very easy! I’m reading a 2MHz wide band from my SDR, where I tuned into 100.7 MHz. The following shows a part of the FM spectrum: The Audio spectrum gives me this, including the pilot signal at 19kHz which indicates that there […]