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Saturday, 13 August 2016

SSTV mode PD120 transmissions on 145.800 MHz FM Aug 15-16

Left monitor listening to Web based SDR, right monitor MMSSTV and Funcube dingle through SDRsharp. Right bottom Baofeng and Lynx 7 tablet also running mmstv



What is SSTV:

This is a way of transmitting pictures over the air, the picture is encoded into sound and sent via a transmitter. The picture is divided into lines and each line is sent one by one. You will see the picture build up infront of you. 

The sound is received by another radio and a computer can decode the sound into the picture.

SSTV from the International space station is transmitted on 145.800 FM and is analogue.
This is good because if you get any interference you just miss a line or 2 of the picture (scratchy) not the whole thing. 

The Event

Apparently the crew have been requested to reconfigure the equipment to PD120 according to Amsat UK site. The MAI-75 Experiment will transmit SSTV images using PD120 mode on 145.800 MHz FM over the course of a few orbits as the space station passes over Moscow. Operators in Europe and South America will have the best chances to receive images. Operators along the US East Coast may have one chance on August 16.

What can you do to take part?

Firstly how do you know where the space station is and when it will be near you?
Take a look at the NASA site: https://spotthestation.nasa.gov/sightings/ and enter your details.
You will get a list of approximate time the ISS will be in your location.


If you have a 144 scanner or radio tune into 145.800 open your squelch and listen for the fax like sounds.
A simple $40 beofeng Chinese radio is enough to get the signal.
Use your phone to record the signal.


Go outside, take your kids outside you don't need to be high up, just clear view of the sky...

Take pictures of your attempts and share them back to us..

If you don't have a radio you can use a web based radio (SDR) to pick up the signal: http://websdr.org.
For UK reception we tend to use: http://websdr.suws.org.uk/ select 146, tune to 145.800 FM
Use the record facility and download the file to your desktop.
Use the R4UAB WebSDR to receive SSTV when ISS is over Russia http://websdr.r4uab.ru/

Now my biggest suggestion here is to record the sound and decode it later on, trying to get the computer ready can be a pain on your first attempt.

You can of course use a more specialist cable connected between your radio and computer, but this article is aimed to help give everyone a chance in the simplest way possible.

If you are lucky enough to record a signal (please do share with us!) now you will need to decode it into a picture.

Android hone or tablet you can use: https://play.google.com/store/apps/details?id=xdsopl.robot36  

For your PC / windows you can use:Free MMSSTV Slow Scan TV software http://hamsoft.ca/pages/mmsstv.php

On the raspberry pi (1,2 and 3) you can install QSSTV: http://users.telenet.be/on4qz/qsstv/manual/installation.html
More on this later....

Once your decoding software is installed you just need to feed in your recorded SSTV sounds and within a few minutes you should have some pictures.

Here are a few images we got in the last year on these special events.


**Please do ask us question or for help... we are here for you!!**