ISS SSTV active again

11:26 Fernando Luiz de Souza 0 Comments

On Saturday, September 6, the ISS Slow Scan Television (SSTV) experiment was activated from the Russian Service Module on the International Space Station on 145.800 MHz FM

On August 27, 2014 a test using the Kenwood TM-D710 transceiver and a new cable had been carried out. It was not entirely successful; a carrier was transmitted but no SSTV audio tones were heard.

On September 6 the earlier issue was rectified and radio amateurs were treated to a day of SSTV transmissions of photographs devoted to the life and work of the first cosmonaut Yuri Gagarin. The pictures were in the PD180 SSTV mode with an additional voice commentary.

Paulo PV8DX contacted AMSAT-UK on Saturday morning with the news that the SSTV had been turned on. He said: “At the end of the passage (ISS) in northern Brazil where I live. I heard the sound of early SSTV. So I went to the WEBSDR in your area [the SUWS WebSDR near London, UK] and I got two images.”

David Barber G8OQW in Chelmsford, Essex was among those who received the pictures and sent them to AMSAT-UK. He was using a horizontal Log Periodic antenna, FUNcube Dongle Pro, SDR# and MMSSTV. David commented that auto slant correction failed for some reason, this was noticed on all the other pictures received that day.
SSTV image received by David Barber G8OQW
Paul Turner G4IJE, co-developer of the SSTV PD modes, says regarding the PD180 mode:  “Don’t forget to either enable “Always show RX viewer” or use the “Picture viewer” (magnifying glass icon) to show the picture at its real resolution of 640 x 496. If you just view as normal you will only see 320 x 248 resolution, which kind of defeats the object of using a high resolution mode.”

All you need to do to receive SSTV pictures direct from the space station is to connect the audio output of a scanner or amateur radio transceiver via a simple interface to the soundcard on a Windows PC or an Apple iOS device, and tune in to 145.800 MHz FM. You can even receive pictures by holding an iPhone next to the radio’s loudspeaker.

The ISS puts out a strong signal on 145.800 MHz FM and a 2m handheld with a 1/4 wave antenna will be enough to receive it. The FM transmission uses the 5 kHz deviation which is standard in much of the world.

Many FM rigs in the UK can be switched been wide and narrow deviation FM filters. For best results you should select the wider deviation filters. Handhelds all seem to have a single wide filter fitted as standard.

On Windows PC’s the free application MMSSTV can be used to decode the signal, on Apple iOS devices you can use the SSTV app. The ISS Fan Club website will show you when the space station is in range.

Listen to the ISS and amateur radio satellites online using the SUWS VHF/UHF/Microwave WebSDR

ISS SSTV Blog and Gallery

ISS Fan Club provides status and tracking information

How to hear the ISS

0 comentários: