iSDR vs HamStudy.org

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 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 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!

HamStudy is not your typical study app. Most study apps focus on practice exams, which is like studying for your math test by trying 20% of the questions on repeat. Study smarter with HamStudy. Instead of taking practice tests with random questions over and over, our intelligent Study Mode tracks your progress as you move through the questions—what you’ve seen, what you haven’t, and where you’re struggling—and focuses your study on the questions you need to see most. Full statistics are provided along the way, giving you insight into how many times you’ve gotten a question right or wrong as well as your overall study progress. Don’t worry, you can still take practice exams whenever you want. You won’t find a better tool to use alongside your favorite learning material. Through collaboration with some of the most recognized names in amateur radio, HamStudy allows you to simply choose from a selection of license manuals, then instantly adapts so you can match your study to the chapters, topics, and sections you’re used to†. Want to study just the questions from chapters 4 and 5? No problem. And when a question trips you up, just tap the Explain button to understand what you missed, review formulas, and read helpful study tips. Features: • HamStudy's intelligent study algorithms work with you to ensure you learn the questions, tracking your progress and adjusting the pace to keep you challenged but not frustrated. • Vetted user-submitted explanations help you avoid the pitfall of just memorizing answers. • Infinite practice exams. Fun fact: it takes around 70 practice exams before you’ll see every Technician question just once. Study more, test less! • Study all current US Amateur Radio question pools: Technician, General, and Amateur Extra. Updates are downloaded automatically, and new pools are always included free when they are revised every four years. • English and Spanish translations included for US Amateur Radio pools. • Includes an ever-growing selection of international question pools, such as Canada, Mexico, New Zealand, and Argentina. • Supports multiple users on the same device, each with independent study history. • Sync your progress across all devices and study online with a free hamstudy.org account. • Share your progress with friends, instructors, or other HamStudy.org users and help each other keep progressing towards that next license exam! HamStudy is proud to be sponsored by Icom. † Disclaimer: HamStudy does not contain the actual instructional material from linked books, but works great with the book sitting on the table next to you! Images, names, and trademarks used with permission.