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SDR Receiver Application Released in Apple Appstore for IOS Devices

Discussion in 'Amateur Radio News' started by K1LPI, Feb 21, 2019.

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  1. K1LPI

    K1LPI Ham Member QRZ Page

    IOS devices have a lot of unused computing power. Barry Medoff, Ph.D. WB2ISS has written an application called SDR RECEIVER for the iPhone and iPad that puts an sdr receiver in your IOS device.

    RTL-SDR compatible app for Apple iOS (iPhone, iPad) has recently been released on the Apple App store. The app is called "SDR Receiver", costs US$9.99, and is used together with an RTL-SDR (or Airspy HF+) server running on a separate networked device such as a Raspberry Pi or PC. The software description reads:

    The app works with an RTL-SDR dongle or Airspy HF+ that is attached to a host Mac, PC or Raspberry Pi running the rtl_tcp server or equivalent. The iOS device, which may be an iPhone or an iPad, communicates over a wi-fi LAN network with the host computer which may be anywhere on the network that is reachable by TCP/IP and that can sustain the required bandwidth. Just connect the iPhone or iPad to the wi-fi LAN.

    • SDR Receiver demodulates AM, narrowband FM and wideband FM signals. SSB and CW will be added in a future release. Key features include:
    • Easily entered and managed lists of stations to simplify station selection.
    • Adjustable squelch that works for both AM and FM signals.
    • Adjustable LNA gain for RTL-SDR.
    • Adjustable audio high pass and low pass filters.
    • Signal strength indicator that shows power level in the signal passband.
    • Multiple sampling rates down to 240Ksps for RTL-SDR.
    • Sampling rate of 768Ksps for Airspy HF+.
    Streaming from an RTL-SDR requires installation of the librtlsdr package including the rtl_tcp utility on the host computer. Streaming from an Airspy HF+ requires installation of server software on the host computer that supports the Airspy HF+ and that streams data according to the protocol used by the rtl_tcp utility. One such server has been made available by Ron Nicholson in source code form on GitHub.

    Requires an RTL-SDR or Airspy HF+, a host computer and server software which are not provided with the application. Here is a link to the article on

    Submitted by K1LPI. Disclaimer: I have no financial interest in this app. I am a beta tester for it.
    73 de K1LPI
    WB2ISS, N2YGI and KK4HPY like this.
  2. KJ7WT

    KJ7WT Subscriber QRZ Page

    OK, so you have to have software running on a local PC or Mac to use this. What is the advantage over just using the PC or Mac to view/demodulate the signals? I was really hoping that this might be an app that allows me to connect my SDR dongle to my iPad via a USB OTG cable, and have a portable SDR radio.
    KC6KNL, AJ4LN and KE9OL like this.
  3. K1LPI

    K1LPI Ham Member QRZ Page

    Using the IOS device provides a mobile solution as long as you are in range of the network. The problem is that the Apple lightning connector can not be interfaced to the SDR dongles or other USB front ends. IOS does not recognize these devices and is locked down pretty tight. The Raspberry Pi is a low cost work around and can be operated headless. The iPhone can also control the Pi using VNC.

    It is possible to make a very low power battery operated SDR receiver by using a PiZero with a wifi module, and a dongle for example, with the ios device serving as the SDR application. As it stands, I can monitor signals on my iPhone from any room in the house or out in the yard. Hard to do that carrying my Mac or laptop.
  4. KE5MC

    KE5MC Premium Subscriber QRZ Page

    I'm not sure all of the statement I left is true. Example: DJI Go 4 application to fly their drone can connect to drone or controller by wifi. The connection to the controller from the application running on an iOS device can be made wired to the controller instead of wifi. The iOS will complain it's not supported, but that can be ignored. I'm not sure how it is done, but expect the application does not rely on much OS support to make it work. I am using a iPhone 8 and DJI Spark or Mavic Air controller.
  5. WB2ISS

    WB2ISS Ham Member QRZ Page

    By streaming IQ data from a server over a network, SDR Receiver can obtain signals from a radio at a remote location that is not directly accessible. For example, the radio and a small server can be placed close to an antenna in a location that would otherwise require running an expensive and lossy feed line, or in a location that might not be accessible at all. If there is sufficient bandwidth, signals can even be streamed over the Internet.

    An iOS application that conforms to Appleā€™s requirements and guidelines is not able to directly connect from the Lightning port to a USB device like the RTL-SDR or HF+ radios. Instead, these devices are connected to a server which may be as small as a Raspberry Pi Zero W, and then data is streamed over WiFi. In some cases, with the addition of an Ethernet adapter, a wired Ethernet connection is possible. The Pi Zero W is sold in bare-board form by Adafruit for $10.

    Compared with using a Mac or PC, SDR Receiver enables handheld operation by running on an iPhone or iPad .

    SDR Receiver is designed for users who are looking for one or more of these capabilities.
  6. W5MJF

    W5MJF Ham Member QRZ Page

    I use TeamViewer on my iPad and iPhone to connect to my pc running SDRuno from anywhere there is Internet with full SDR control and Audio
    easy as Pi :)
    K0WJ, N2GBR, KJ7WT and 2 others like this.
  7. WW4LDO

    WW4LDO Ham Member QRZ Page

    My shack PC is a Mac Mini; I can screen share to my Macbook Pro, but WSTJ-X always seems to crash or disconnect from my rig whenever I do!
  8. KE8KUY

    KE8KUY XML Subscriber QRZ Page

    sounds like a big waste of 10$ to me. for all the hassle youd be better of running teamviwer going remote and call it a day. imo
    K0WJ and (deleted member) like this.
  9. K1LPI

    K1LPI Ham Member QRZ Page

    Teamviewer does not run on iPhone or iPad devices. It is also a remote desktop application and exposes your computer to the remote user. SDR Receiver does not have access to any other data on your computer so it is a very secure application. As more portable rtl_tcp servers and front ends are evolving this approach will emerge as a very useful receiving technology.
  10. N1FM

    N1FM Ham Member QRZ Page

    Team Viewer works great on iPhone and iPad devices. It supports audio and video and it's password protected. It also comes with its own VPN. For extra security you can put sensitive files in a locked directory, and only give the authentication creds to people you trust. You can use Team Viewer to listen to online SDR websites, or your own SDR, and/or anything connected via hardware to your computer. It takes 5 minutes to set up.

    It's also free.
    K0WJ, KJ7WT and KE8KUY like this.

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