Introduction: Decode Digital Audio Signals From Earth or Space.

There is quite a Few Options But let's start by keeping this simple and fun.

  1. Android Smartphone
  2. Internet Connection (Wifi Or Data)
  3. Free Android App


Download and Install Robot36. --> Google Play Store. <--

Start the app and leave it running.

Now open the YouTube app and have a listen to a slow scan signal by going to here --> Youtube SStv Test Signal<-- listen to this weird digital noise and after the video is done come back to Robot36 and notice the picture it has decode. Now you can press the pause button before leaving the app.

Step 1: ISS, Satellites, Shortwaves, Marine, Uhf, Vhf, Etc....

Now that we have our feet wet there is an endless variety of signal we can decode, one being the International space station that send pictures thru slow scan tv. I will be adding to this instructables on how to go about it and the all the other option available to enjoy hobby of decoding live radio signals.

Lot's of possibilities even without any radio equipment. Stay Tune...

Step 2: International Space Station !!!

International Space Station broadcast live from space signals you can decode. it is not always transmitting I will list a few ways to verify when it may be happening.

You may have the chance to decode some pictures October 27 !!! Oct 29 and still going strong !!!!

SSTV will be active starting October 27 around 10:00 UTC. The images will highlight the NASA on the air activity celebrating 60 years of NASA. This event is dependent crew responsibilities on the ISS and to can sometime change. The transmissions are expected to be broadcast at the usual frequency of 145.800 MHz using the PD-120 SSTV mode.

12 images will be down-linked, but this time with 6 featuring the SCaN educational activities while the other 6 images will commemorate major NASA anniversaries, ie when NASA was established, astronauts first landing on the moon, etc. In addition to the fun of receiving these images, participants can qualify for a special endorsement for the NASA On The Air (NOTA) celebration event. To learn more about NOTA, visit

Let's bring out the rabbit ears and listen to 145.800 Mhz, or better let's connect to a receiver with a very tall antenna !

Visit this WebSDR here -->

Not too far down you will notice.
ISS Voice/SSTV / Packet Elevation: -42° Range 9000.0 km .

(*WebSDR is a Software-Defined Radio receiver connected to the internet, allowing many listeners to listen and tune it simultaneously. SDR technology makes it possible that all listeners tune independently, and thus listen to different signals.)

The receiver site is located near the town of Farnham in the South Eastern part of the United Kingdom at Latitude: 51.23, Longitude: -0.82

.Click on Voice/SSTV / Packet this will bring you to the 145.800 mhz freq now we have wait for Iss to be in receiving range of the anntenna you will notice the range get closer or farther when in a range of 500km with a good elevation from the horizon we should be able to listen for radio communication from ISS ! Have your smart phone running robot36 and not too far from your speakers to decode the signal that we may hear coming from International Space Station.


And this web sdr radio antenna located in Milford, Pennsylvania - Northeastern USA.

Have a look at to see if the Iss in near Pennsylvania.


Also you may click start record from the Websdr page to have a copy of that signal to decode anytime later.





Freq you can tune around to listen in stuff orbiting earth.

•International Space Station FM =145.800

•ISS Packet Digipeater = 145.825

•FunCube-2 = 145.930 – 145.950

•AO-73 (FUNCube-1) = 145.950 – 145.970

•AO-7 (Phase-2B) =145.975-145.925




A list of other Radio receiver connected to the internet.

Free windows sstv decoder software




* Photo Credit Nasa. (no copyright picture)

Still more to come. :-)

Audio Contest 2018

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Audio Contest 2018