ARISS ISS SSTV

One of the things that kicked me back into ham radio was the idea of getting SSTV from the International Space Station. 

Given the 24th-31st December event, I thought it was a great time to try again and see just how well I can do with what I've got. 

I setup SDR Console before I left to go interstate for Christmas. It has some great satellite tracking built in, and when configured will help show you both where it is in the path, but allows for doppler. I had it hooked up to my RTL-SDR and the discone antenna I use for VHF/UHF, and went away.

I came back to the expected "not much". 

After watching a few passes, I noticed that I could hear it on the radio, but not the SDR. It turns out that quite simply there was an out of the box filter being applied at 3 kHz, that was essentially cutting the signal. Doh!

There was also the slight issue that the G90 was on, and still pushing audio into the PC. I can't hear it because there are no speakers connected to the box, and I use it remotely, with the audio left on the PC so it loops around to the G90 for FT8.  

I had to disconnect the G90 to ensure that the audio wasn't being contaminated.

I set the filter to 16kHz, then waited for the next pass that was close enough - about 9 hours away. Doing a side by side, I yet again heard the signal on the radio (the IC-706MkIIG) long before I heard it via the RTL-SDR. The signal was by no means great either way. It cut in or out, even as I manually adjusted the radio for doppler. The SDR managed to pull a few good lines here and there..

These were the "best" images I'd ever received, yet hardly anything to write home about. 

The first observation was that quite simply, the RTL-SDR does not have the same sensitivity as the IC-706. The Icom is way ahead of it, and holds the signal long after the RTL-SDR looses it. 

The second observation is that my antenna is probably less than ideal. It's a static vertical, and it's a fraction of a wavelength. Some people seem to be able to pull this off with a nice close pass. I can't. I want to replace this discone anyway - perhaps it's replacement will bring about some improvement. I do know that I'd be better served with a beam antenna (and a rotator if it's going on the roof). 

Waiting for the next closest pass, I decided to hook the headphone socket up to the mic input on the PC, and the headphones to the headphone socket, so I could actually hear it. 

Once the pass started, I manually accounted for doppler. Low and behold, some success...

A little noisy at the start as I fine tuned the signal as it first appeared.

As the second came down, things started out OK. About 1/3rd of the way through, I got a little fade, but it came back briefly, before it started fading in and out. No amount of adjusting for doppler was going to bring it back. It was going.

This was as good as I could do with a pass that was as close as it'll ever get. This pass was around 11pm on 28th December - rather late for me. 

Deciding that the manual receive with a full radio was indeed a success, and hoping that when the cable arrives that I can get enough CAT control over the IC706 to be able to drive it with the SDR Console software well enough to let it handle the doppler tuning, then that might be the future way forward... or maybe just a new radio (can never have too many), I decided that it was time for bed.

I set the SDR back up and left it. The next pass didn't look that great.

Still, I awoke to:

These are still some of the best images I've ever received with the RTL-SDR. 

I'll keep trying while the opportunity is there - I'll use the IC706 when I can and leave the RTL-SDR for when I can't. With some luck I'll get the discone replaced with something bigger and better suited to my needs before the next events occur (whenever that is). Maybe one day I'll get super keen, buy a compass, build a beam antenna and drag my backside outside. Who am I kidding? I'll buy one of those SARCNET kits, put it together and use that. Standing around holding an antenna is not really my thing when I can have tech that does it for me.