ON8NT - OP8NT - OO8NT
Having fun with hamradio using low power and simple antennas!
Receiving SSTV pictures from the ISS
(and other digital modes)
SSTV = Slow Scan Television
ISS = The international Space Station
On the ISS nearly all astronauts and Cosmonauts have a amateur radio licence as part of their "space" training. For several years the ISS played an important role in convincing youngster to follow STEM courses (Science, Technology, Engineering & Maths). That's why there are regular 'schoolcontacts' going on where members of the crew on the ISS talks to a group of youngsters. Those schoolcontacts are easy to hear by everyone who has a simple receiver and antenna, I regulary report on the schoolcontacts i heard at my home on this page.
A less known fact is that crewmembers on the ISS are also transmitting SSTV pictures several times a year. Those transmissions are anounced in advance through different channels like f.e. the AMSAT UK website.
Those pictures can be received and decoded by a simple receiver, antenna and software.
Here is an example of a pic decoded at an elevation of 3 degrees above the horizon!
In this page I will describe how I am doing this, There are off course different ways to be succesfull in receiving those picture, but I will describe the 'simple' and 'easy' way to do this, which is my prefered way.
The radio
The pictures are transmitted on a frequency of 145.800 Mhz in the 2 metres amateur radio band in FM (Frequency Modulation).
Every receiver that can receive this frequency can be used, even (cheap) scanners, RTL dongles...
The Antenna
If you have the means you can go for a beam antenna with computer controlled rotator... But this is not necessary at all, a simple (vertical) dipole or groundplane antenne, that you can make yourself will do the job, I even used the rubberduck antenna on my portabel transceiver to receive those signals!
The software
In the past years I used different setups and free software. I will here describe the different approaches that i used with success, in the past, using a windows PC and a Android tablet.
A lot of experimentation took place to reach this, in fact not all attempts where successful from the first time, so be ready to spend some time experimenting and learning new things along the way!
First of all you need to determine when the ISS will fly within the reach of your location! Some free applications are at our disposal here:
In the internet browser of your PC, surf to http://amsat.org.ar/pass.htm
At the bottom of this page you can set your location and then search for 'ARISS' and you are ready! Now you can see when and how the ISS wil be heading over your location!
Another possibility is using free Android applications called 'HEAVENS-ABOVE' or 'AMSATDROID FREE' that you can download from the Google Play store.
Now we go to actually decoding the strange tones coming from the speaker of your receiver with the help of a (cheap) interface or just by using no cable or interface just the audio.... and free software!
1) The cable + interface approach (for windows PC and Android tablet).
As a cable and interface i use the 'MiniProSC' from ZLP Electronics in the UK:
http://www.g4zlp.co.uk/unified/DM_MiniPro_SC.shtml
This interface works very well on my Windows PC and on my Android tablet with the help of a OTG-cable! And not only for SSTV but for every digital mode like PSK, RTTY, WSPR...
More info can be find on the site of OH8STN
http://oh8stn.org/
ZLP MiniProSC Yaesu FT-817ND Android Setup & Configuration Ham Radio Digital Modes EP02.
Setting up your USB audio interface on an Android device. a Video by OH8STN
https://www.youtube.com/watch?v=_afmWGV08GE
AND (very important):
How to Enable Disable USB Audio Routing for ZLP or SignaLink on Android, video by OH8STN
https://www.youtube.com/watch?v=caDarGu4UUc
With the android Tablet and OTG-cable I use the 'Robot36' app, that you can download for free from Google play.
On my Windows 7 PC I am using the free RXSSTV progam from on6mu:
http://users.belgacom.net/hamradio/rxsstv.htm
2)The no cable no interface just audio approach (for Android tablet or phone).
As I have no direct cable from my ID-51E to my Android tablet, I used the internal microphone from the Android tablet holding to the speaker of the ID-51E in the past, but this doesn't giving satisfying results. For the pases of 14/02/17 I used a different procedure, using the 'record' facility on the ID-51E, which was more successful and produced better pictures:
1) Tune to 145.800Mhz FM (Wide)
2) Activate the 'record' facility of your transceiver (read the manual of your TRX! Study and practice this beforehand...)
3) Keep the squelch ON: The ID-51E starts the recording only if there is a signal present! And the signal of ISS is very strong
4) At the end of the transmission stop 'record' (see the manual of your TRX! Study and practice this beforehand...)
5) Put your transceiver OFF, because we will pulling the SDcard out of the transceiver in a safe way, maybe you will need a MicroSD adapter
6) Put the SDcard in your PC, we will now search for the audiofiles (in WAV-format on the ID-51E) on the SDcard and copy them to a map on the harddrive of your PC
7) Remove the SD card safely from your PC and put it back in your TRX
8) E-mail the audiofiles to an e-mailadress you can access on your Android tablet (in most cases a Gmail account)
9) Start your SSTV app on your tablet, in my case the 'Robot36' app (that you can download for free from Google play, again practice and play with this app)
10) Start/play the audio file on your tablet, Robot36 will autodetect the right mode...
11) If the audio file is finished you will find the SSTV pic in the Robot36 app, and you can now SAVE the SSTV pic
This can probably be done with other transceivers with a 'record' facility...
So this is what works for me! there are certainly other ways to do the job, you can always contact me with your suggestions and questions at my contact page!
Good luck and enjoy the hobby!
73!
Jef
ON8NT
Here are some more pictures decoded during the December 2017:
