iSDR

iSDR is the first and only software defined radio application compatible with the Apple iPhone®, iPod touch® and iPad™. iSDR is for experimenters and amateur radio enthusiasts looking to construct a truly portable software-defined radio receiver. Additional hardware is required to receive live signals. Currently iOS devices will not work with RTL-SDR USB dongles, and they are not supported by iSDR.

PLEASE NOTE: Receiving live on-air signals using iSDR requires purchasing or constructing a "quadrature sampling detector (QSD)" RF front-end device, and connecting it between an antenna and the microphone input jack. Alternatively, iSDR can be used to implement a panadapter for use with a compatible radio receiver. Without a QSD RF front-end, or a connected radio, iSDR will play I/Q recordings of actual radio signals. Additional recordings can be loaded into the app using iTunes file sharing - some selections are available free to download from the Internet. Visit the support web site for more information.

Please contact us directly if you experience any issues with using this app. We will respond promptly when provided with details.

iSDR is NOT RECOMMENDED for use on iPhone 3Gs or iPod touch 3rd Gen - Although iSDR will install and launch successfully on many older devices, they do not have the processing horsepower to keep up with the demands that iSDR places on the CPU. Sluggish performance and audio distortion may result.

When iSDR is used to receive live radio signals, receiver performance will depend largely on the quadrature sampling detector and antenna that you use.

iSDR is the only software defined receiver application for use on mobile handset devices and iPad. Despite its extreme portability the app utilizes the same digital signal processing techniques found in PC-based SDR receivers. It does frequency domain filtering using a theoretical "brick wall" sinc filter algorithm to provide steep and deep bandpass filtering. iSDR doesn't utilize any DSP hardware, but instead uses the iOS device's processor to implement DSP algorithms.

Features

o Six receive mode settings: USB, LSB, CW, AM, FM* and Binaural.
o Selectable bandwidth settings for each mode.
o Signal strength meter covering 120 dB of dynamic range with peak and average power indication.
o Three AGC settings: fast, slow, and off.
o Three display modes: Spectrum, Waterfall and Oscilloscope.
o File sharing** supports downloaded audio-format spectrum files sync'd using iTunes.
o Most PCM file formats are supported, including .wav and .caf.
o Embed the center frequency in your file names and iSDR will automatically display the correct frequency!
o Built-in example audio file means the app is always ready to provide an authentic SDR demonstration!
o Tune quickly using a single touch to the display screen, or tune precisely using the rainbow tune bar.
o Change radio settings with a simple double-tap action to the red cursor, mode text, AGC indicator or signal grid!
o Up to 44.1 kHz of available spectrum bandwidth.
o Dimmable semi-log or linear spectrum grid (native Settings app only).
o Adjustable CW offset (native Settings app only).
o Monaural microphone input automatically adjusts display to 22 kHz bandwidth.
o Automatically detects if external audio is available for receiving live signals (menu selectable).
o Reverse I/Q stereo input logic (menu selectable).
o User-adjustable displayed center-frequency setting, including negative frequency values (menu selectable).
o Display lock prevents settings from being changed inadvertently.

*FM mode is not supported for monaural signals, and will not appear as a mode selection unless stereo audio (live or recorded) is available. Narrow band FM only: 16 kHz or 11.2 kHz bandwidth.

Please contact Digital Confections with your questions and suggestions!