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iSDR app for iPhone and iPad


4.0 ( 7200 ratings )
Utilities Education
Developer: Digital Confections LLC
0.99 USD
Current version: 5.1, last update: 4 years ago
First release : 17 Nov 2011
App size: 36.3 Mb

PLEASE READ THE ENTIRE DESCRIPTION BEFORE PURCHASING. 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 only play I/Q recordings of actual radio signals. Additional recordings can be loaded into the app using iTunes file sharing - some recordings are available free to download from the Internet. Visit the support web site for more information.

iSDR includes a sample I/Q recording featuring 30 seconds of a ham radio contest. This is for demonstration purposes only. It is not meant to fool you! It is to allow you to experience how the app works without having to do anything yourself: just turn it on. You can download and play your own files if you like. Please see the support page for details. AND PLEASE contact us directly if you experience any issues with using this app. We will respond promptly when provided with details.

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 a 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 doesnt utilize any DSP hardware but instead uses the iOS devices 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 synced 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 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 the 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).

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

Please contact Digital Confections with your questions and suggestions!

Pros and cons of iSDR app for iPhone and iPad

iSDR app good for

Amazing app for the price! Works great on iPhone 4 and iPad 3, ideal to demonstrate the power of SDR or simply to demonstrate HF radio reception. Comes with 30 seconds of recorded signal in the 40 meter radio band with sample voice and morse code than you can tune to.
Even without the external hardware, the app provides an excellent hands-on introduction to the SDR technology via the built-in loop of a chunk of RF spectrum in the 40m amateur band during a busy contest. The app code seems to be essentially perfect. The GUI is perfection. The only part that Ive not figured out is the binaural effect (not what I was expecting, Ill keep playing with it in case Im missing it). Many thanks for a great app.
It will be fine to receive the IQ data from the network in OsmoSDR format

Some bad moments

Bidon marche pas juste une exemple Doesnt work just an exemple of incomming transmission --
Its only a simulation, a fake!! Give me back my money. Thanks
Great app, used with recordings and was amazed! Waiting on a SoftRock Lite to test it live, but I am sure it will perform great! Thanks for making SDR portable. K7SWF
Worked great, and then it just quit working when I installed e new version. Hope it gets fixed, as theres nothing at all like it.
This is an amazing app that does everything I would expect from an expensive paid app. Certainly the center piece for a great QRP or Field Day go kit.
This is an outstanding application. I use it extensively to practice CW copy. Support is quick and personal.