[HCRA] Surfin’: iPhone Gets Software Defined Radio

[Ed LaCombe]

Surfin’: iPhone Gets Software Defined Radio
 06/11/2010 
By Stan Horzepa, WA1LOU
Contributing Editor
This week, Surfin’ discovers a software defined radio (SDR) in an iPhone.
This is so cool, my typing fingers are numb from the cold: a software defined radio (SDR) application for the Apple iPhone, iPod touch and 
iPad called iSDR. It is a portable software-defined radio receiver designed for experimenters, shortwave listeners and Amateur Radio 
operators -- and it is free! 
A caveat: receiving live on-the-air signals with iSDR requires 
purchasing or constructing a quadrature sampling detector (QSD) RF 
front-end device that connects between an antenna and the microphone 
input jack of the iPhone, iPod or iPad. Without the front-end, iSDR will play an internal audio file recording of actual radio signals recorded 
off the air during the 2008 CQ World Wide WPX contest.
The iSDR developers list the following features of the app:
	* Three display modes: Spectrum, Waterfall and Oscilloscope
	* Frequency display with 100 Hz resolution with a touch to the 
display screen
	* Up to 44.1 kHz of available spectrum bandwidth
	* Monaural microphone input automatically adjusts display to 22 
kHz bandwidth
	* Automatic display rotation
	* Recorded audio file built in for off-line use without external 
audio
	* Automatically detects if external audio is available
	* Five receive modes: USB, LSB, CW, DSB and Binaural
	* Reverse I/Q microphone input logic
	* User-adjustable center frequency setting
Visit the iSDR developer’s Web site for more information.