What is RTL-SDR?
RTL-SDR is a very cheap software defined radio that uses a DVB-T TV tuner dongle based on the RTL2832U chipset. With the combined efforts of Antti Palosaari, Eric Fry and Osmocom it was found that the signal I/Q data could be accessed directly, which allowed the DVB-T TV tuner to be converted into a wideband software defined radio via a new software driver.
Essentially, this means that a cheap $20 TV tuner USB dongle with the RTL2832U chip can be used as a computer based radio scanner. This sort of scanner capability would have cost hundreds or even thousands of dollars just a few years ago. The RTL-SDR is also often referred to as RTL2832U, DVB-T SDR, RTL dongle or the “$20 Software Defined Radio”.
There are many other software defined radios better than the RTL-SDR, but they all come at a higher price. Currently we think that the Airspy ($199) and SDRPlay ($149) SDR’s are the best low cost RX only SDR’s. Then there are the HackRF($300USD) and BladeRF SDRs ($420 and $650), which can both transmit and receive.
What is Software Defined Radio?
Radio components such as modulators, demodulators and tuners are traditionally implemented in hardware components. The advent of modern computing allows most of these traditionally hardware based components to be implemented into software instead. Hence, the term software defined radio. This enables easy signal processing and thus cheap wide band scanner radios to be produced.
Projects related to astronomy coming soon.