Pictures by radio - SSTV World
Do you know that it is possible to send images though radio frequency? How cool is that? Join this activity to learn how to turn your images into a sound, transmit them, and then turn them back into images.
Slow-Scan TeleVision (SSTV) is a technique to transmit and receive static pictures via radio. Basically, the image is converted to a sound, which is transmitted via radio; the received sound is then converted back into an image.
In this way, it is possible to exchange personalised images, and perform complete radio communications by adding text on it. SSTV images can finally be stored or printed as a nice “souvenir” of the radio contact.
Several applications are available to convert SSTV sounds into images. As example, MMSSTV is available for Windows, while in Android the Robot36 app is available.
Most applications are automatically able to detect the correct SSTV codification format (e.g. Robot36, Martin 1, Scottie 1, etc.).
Expert amateur radio operators are equipped with interfaces to connect the radio receiver to the device that decodes SSTV. In your case, you may find yourself in three alternative conditions:
- If the SSTV sound is emitted from the loudspeaker of a device (e.g. a radio), you should put the microphone of the decoding system (PC/laptop or mobile phone) as close as possible to the source of the sound. The environment should be as quiet as possible, every collected noise will spoil part of the decoded image!
- The device that emits a SSTV sound is also the one that should collect and decode it. To work this out with a PC/laptop, install the software (Virtual Cable) that virtually injects the sound output into the sound input. The software creates two virtual audio devices (CABLE input, Cable output), one for the input and one for the output. When decoding SSTV images, these devices should be contemporarily selected; during this activity you will no longer hear sounds … but the computer will.
To complete this activity, you must decode the sounds and upload the images on a Padlet at: https://padlet.com/worldscouting/pictures-by-radio-sstv-world-56j1ph7yd740amoo
To add your images, follow these steps:
- After opening the Padlet page, click on the PLUS SIGN in the bottom right of the page;
- Choose your location, typing the city, state, country. When you start typing a list of options wil appear.
- Add your image.
- Write something about the activity,
- Click on PUBLISH in the upper right-hand corner.
You can add as many images you want. Let´s show our skills to the world.
Here you will find 10 audio files containing SSTV sounds to be used to convert into images.
Challenge Code