We are receiving you - My experiences getting Slow Scan TV pictures from the International Space Station. (Part 1)
Part 1: Getting back into Radio
Recently, I have been getting back into amateur radio. I never lost interest per say, but had put it aside due to time constraints and other interests, not to mention the fact that my rooftop antenna was coming into a room that was repurposed after having a child. I still kept going to ham fests, turned up at related hackerspace events, and even purchase an HF rig, but I didn’t quite have the interest at the time to keep up.
Back in October, I had volunteered to represent this very hackerspace at a ham fest, and when I could duck away from our booth, I had a look about. I ended up picking up a cheap radio, a Radtel RT-890. It was $25, and had a very “Baofeng” energy about it. For those not in the know the Baofeng UV 5R is a cheap ham radio. There’s a lot of controversy about it among some hams. I own one, and I find it has very little personality as a radio. Very basic, not really that fun to use, and then you could even pile on the other problems that people have. That’s not the purpose of this column, if you are curious and not in the know, a quick google search will give you tons of results and discourse on why these are a love it or hate it radio. Personally? They’re fine, mostly harmless, but I don’t really want to daily drive one.
But as I looked into the Radtel, I noticed: Hey! You can put custom firmware on this! For what it’s worth, I’d recommend one of these over a Baofeng any day. My jury is still out on whether or not I recommend the Quansheng, the other hackable radio everyone talks about. I’ve already had problems with mine (grabbed it on black Friday) after modding it, and eventually just set it back to stock. Right now as I write this that’s where it lies, but that may change as I journal this out.
We’ll skip forward a bit fast here. The Radtel very much got me back into ham radio. I modded the Radtel, used Chirp (a radio programming software) to clone my Baofeng’s contacts over, and cloned the resident Baofeng at CT Hackerspace as well. I pulled out my old Motorola VHF rig, and started considering setting that up as well (we’ll get to that later on). I had a friend help move the my roof antenna over to “the lab”, the room in my house where I would be housing my radios. I began to study or my amateur general ham radio license so I could just get right on HF. But quickly discovered that as the old saying goes “One does not simply jump on HF out of the box”. Down the road I may journal the road to getting my HF working or at least what I had and have since acquired for that. Suffice to say, I am still putting things together, and while hitting up repeaters on VHF and UHF isn’t bad, a lot of my time for ham radio comes late at night on the weekends, or on days off from work. And a lot of people aren’t listening at times I am, or maybe not wanting to interact at the time.
During this time, in the lead-up to Christmas, my 3 year old daughter was starting to notice me carrying my radio around. She asked if she could use it, so next thing I knew, I was ordering her a set of FRS radios to get her started appropriately (Those cheapo hiker radios that you can probably find at Walmart, that overstate their broadcast range). But after a few days I had an idea. Slow scan TV (hereafter referred to as SSTV) is a mode of ham radio that involves sending pictures over the air waves. It sounds like a dial up modem, and actually is more akin to a FAX than television. It got it’s name “Television” from the fact it was originally displayed on heavy persistence picture tubes similar to those that were used on radar displays.
All of these can be sent and received with that very set of FRS radios. All you have to do is have a picture file in mind, and two applications on your phone. I have Android, I’m sure IOS has equivalents. On Android, the application to send is called SSTV Encoder, and the receive app is Robot36.
If you send on one end with the encoder, and play the sound into one FRS walkie, you can have another person receive on the other one with Robot 36. As one could imagine, this is quite entertaining to a toddler to see a picture of a duck load in slowly with “squelchy modem like noises”
As this was going on, I remembered: The international space station occasionally sends out SSTV broadcasts. And the Station is “easy” (note the quote marks!) to pick up via a small portable radio (I have three cheap ones). So the question became: Did the space station always broadcast this? A quick Google search lead me to the fact that the space station would be transmitting SSTV pictures between Christmas and the 5th of January. So it was time for to start formulating a plan to pick up some SSTV.
More on this in part 2.
- Reed