A Radio Transmitter for the Masses

Any amateur dabbling in radio technology knows the high cost of hardware. Peripherals designed to work with software defined radios (SDR) can cost anywhere between $150 (Funcube) to $4,500 (Matchstiq).

While the Funcube operates between 64 MHz and 1,700 MHz, the Matchstiq transceiver covers signals from 300 MHz to 3,800 MHZ with channel bandwidth up to 28 MHz. The two devices have established niche markets, not every radio hobbyist is willing or able to fork out the sums involved, less so newbies.

Enter the Realtek  DVB-T dongle. Antti Palosaari, a DVB kernel developer, discovered that the  RTL2832U chip found in Realtek DVB-T dongles can be reprogrammed to transfer raw radio signals (I/Q samples) to a host computer. This presents hobbyists with a low cost ($20) software defined radio which can be used to receive raw signals between 52 and 1700 MHz. An obvious digital signal processing candidate is FM radio. Unfortunately, because of the inordinately high demand for the device within the amateur radio community, the Realtek dongle is now impossibly hard to get.  Now that is good news for engineering.


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