Software Defined Radio (SDR)

Related wiki pages : Digital Signal Processing (DSP), Transceivers, Manufacturers Websites

A software-defined radio is one in which functions such as tuning, filtering and modulating/demodulating are performed by software rather than hardware. The ease with which this is now possible is due largely to advances in digital electronics.

An SDR is essentiall a computer attached to an RF front end that performs the usual functions of detection and transmission of radio signals. The key physical component is perhaps the analogue to digital converter that connects the front end to the computer. Processing of the digital output is carried out by a CPU. This has a number of advantages:

• The need for special purpose hardware is greatly reduced
• New functions can be added to the radio by changing or adding to the software

The cost of SDR devices is continually falling, and it has recently (as of April 2012) reached the point where price is no longer an obstacle to the beginner. While high quality SDR transceivers still cost over US$1000, a fair quality (but very usable) plug-and-play receive-only software radio can be had for as little as US$11, in the case of the RTL2832.

Other than a computer, a typical software radio requires these things:

• An SDR device to convert analogue RF signals into digital data. Wikipedia has a good list of SDR devices.
• A computer program to demodulate the digital data. See the List of SDR programs.
• An antenna suitable for receiving RF bands of interest
• An optional transverter or downconverter to "move" a section of the RF spectrum into a range the SDR device is able to tune to, if you wish to receive transmissions outside the SDR's native tuning range

External links

• Flex Radio. Manufacturers of SDR for amateur use.
• SDR forum Not exclusively for amateur SDR.
• HPSDR High Performancs Software Defined Radio
• HPSDR wiki
• RF Space manufacturers of the SQR-IQ, SDR-14 and SDR-IP software defined radios.
• Wikipedia:Software defined radio
• Ultra-cheap SDR mailing list - with a focus on using cheap SDR devices like the RTL2832
• RTL-SDR Blog with information on using cheap RTL2832 SDR devices.

Radio apparatus
Apparatus	Keys - Morse * Kits * Radio/PC Interfaces * Receivers and transceivers * Software Defined Radio (SDR) * Vintage Radio
Manufacturers	Alinco * Elecraft * Flex Radio Systems * MFJ * Icom * Kenwood * RF-Space * Ten Tec * Yaesu
Transceivers	Alinco DX-70TH * Elecraft K1 * Elecraft K2 * Hendricks QRP Kits * Icom * Kenwood * Yaesu
Projects	Build a simple 160 metre receiver * Powering a hand held transceiver from an AC power supply
See also	Antennas