Amateur radio satellite operators gear up for the week long SSTV event!

This image was posted by the ground team of Amateur Radio on International Space Station yesterday on X. It was reposted by a lot of amateur radio satellite enthusiasts including me and the numbers are growing. It is possible to receive SSTV or Slow Scan Television images from the Space Station even without a great setup for satellite reception. As the downlink is on 145.800 MHz, even those without a dual band radio needed for working the voice transponder, but having a VHF radio, can download the SSTV images. Moreover, the events usually use higher power at least in the range of 25 W unlike the usual 5 W power of the downlink of voice transponder. During past events, I have been able to get the images even with omnidirectional CP22E VHF antenna and without Doppler correction. So anyone with just a VHF radio can attempt receiving the SSTV images, though better quality images will be obtained with directional antennas and Doppler correction. High elevation passes in the region may be audible even with the stock rubber duck antenna.

ARISS team has requested us to submit the decoded images to the ARISS SSTV image archive. You can download Robot36 app for decoding the images from Google Play Store on an Android phone. As the mode is shown as PD 120, it will take two minutes for decoding an image. There is option to select the mode in Robot36 app before you plan to decode the image from the audio signals received. You can directly decode during the pass of the satellite by keeping the phone with app open, on the loudspeaker of the radio. Alternatively audio can be recorded and decoded at leisure by playing back the audio to the app. Doppler tracking can be done using the live display on Argentinian Amsat webpage during the satellite pass. Pass timing and direction can also be obtained from the same page. When the signals are being acquired by the radio, it will be heard as a buzzing sound different from the usual hissing noise of the open squelch in FM radios. Test recordings available at Amsat UK webpage for you to verify functioning of the app prior to the SSTV event.