SDR Receiver 4+

Software Defined Radio

Transition Technology Ventures, LLC

    • 3.7 • 13 Ratings
    • $9.99



Demodulate and play AM and FM signals received by an RTL-SDR, Airspy HF+ or SDRplay radio. Requires a radio and a host computer which are not provided with SDR Receiver and must be separately installed and configured. Streams data from an rtl_tcp, hfp_tcp or rsp_tcp server application which are free and open source applications. The appropriate server application must be installed on the host computer and configured for the attached radio.

SDR Receiver is a Software Defined Radio (SDR) that processes, demodulates and plays AM, narrowband FM and wideband FM signals. Listen to communications from aircraft (AM), amateur repeaters and VHF handhelds, police and fire, NOAA weather reports (narrowband FM) and commercial broadcasts (wideband FM).

• Easily entered and managed lists of stations simplify station selection.

• Export and import lists of stations in CSV or TSV format.

• Adjustable squelch that works for both AM and FM signals.

• Adjustable LNA gain (for RTL-SDR and SDRplay radios).

• Adjustable audio high pass and low pass filters.

• Selectable IQ Offset eliminates DC errors.

• DC Blocker option reduces spurious errors.

• Signal strength indicator that shows power level in the signal passband.

• Multiple sampling rates to accommodate different network bandwidths.

• Selectable 8-bit or 16-bit sample size streaming from Airspy HF+ and SDRplay radios.

• Option to play audio over AirPlay to a HomePod, HomePod mini or any AirPlay compatible device.

• Stream synchronized audio to multiple AirPlay 2 compatible devices.

• Lock Screen shows controls and streaming station information.

• Custom URLs enable another application on the same device to set the station and start streaming.

• Supports VoiceOver.

SDR Receiver processes signals that are streamed over the network from a host computer (Mac, PC or Raspberry Pi) that is attached by USB bus to an RTL-SDR, Airspy HF+ or SDRplay radio. An rtl_tcp server or equivalent application running on the host computer receives baseband IQ data from the radio and streams the sampled signals over the network to the iPhone or iPad running SDR Receiver.

Requires an RTL-SDR, Airspy HF+ or SDRplay radio and a host computer which are not provided with the application. Support for 192 ksps and 384 ksps Airspy HF+ sampling rates requires Airspy HF+ firmware version R3.0.7 or later, and hfp_tcp version v.1.2.117 or later.

What’s New

Version 1.2.6

Bug fixes.

Ratings and Reviews

3.7 out of 5
13 Ratings

13 Ratings

KD0 ,

Very basic, but stable..

First and foremost (as a few left negative reviews as they didn’t know what this exactly did before purchasing), you need (at minimum) an SDR dongle running on a computer (Mac, PC, Raspberry Pi, etc) in order to use this application. This app is designed to receive a stream of data across a network (LAN or internet) from an SDR source. To stream from the internet (i.e, over LTE to back to your SDR source), you may need to forward a port on your router. The default port for SDR is just 1234.

I have this and the other new one just released (one with waterfall). Both are working ok on iPhone and iPad, In fact this one may even be more stable than the waterfall one. For stability, I give it four stars marking that it’s “very good” and I like it, however there is room for more features. The presets are pretty useless if you don’t live in the California area that it looks like they are for. Restoring the presets is pretty useless as the majority of users will just delete them, use their own freqs, and never need to restore them. While adding a waterfall isn’t really necessary (in fact, it may degrade performance as it has to draw all that), adding LSB/USB modes is something I’d love to see added. Along with, perhaps, squelch. With LSB/USB, especially if they are stable using low freqs through upconverter, I would give this full 5 stars. I’m more interested in performance than eye candy.

I’ve been using this app more often than the “waterfall” one. Sometimes less is more. However, for LSB/USB, I still have to turn to the other app...

Danzigism ,

Works great with an RTL-SDR Dongle

Love this app. Super simple and stable. I would LOVE the addition of SSB modes (LSB and USB) so I could listen to what's happening on the HF ham bands. For now, it's perfect for monitoring my local FM repeaters and FM broadcast stations. I work in a concrete building that can't get any radio signal. Being able to connect to my Raspberry Pi at home that has a cheap RTL-SDR dongle plugged in to it, is a really nice thing to have. If you guys ever add a SSB and a waterfall, this will be the BEST SDR app for iOS no doubt. Keep being awesome devs! Thank you!

TSPix ,

Spot on!

Great UX and quality app! Able to stream easily from my phone using rst_tcp on my Raspberry Pi. My only ask is to add squelch to the main screen.

App Privacy

The developer, Transition Technology Ventures, LLC, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy.

Data Not Collected

The developer does not collect any data from this app.

Privacy practices may vary, for example, based on the features you use or your age. Learn More


  • Family Sharing

    Up to six family members can use this app with Family Sharing enabled.

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