Testing my home SSTV setup

Yesterday I did some tests, into a dummy load for the time being, of my setup at home for SSTV transmission, I can receive using my phone however receiving using the computer would be a better option here, though I have yet to get a decent adaptor to convert the TRRS output on the KT-8900D to a standard lead suitable for driving a mono speaker (though the computer input is in fact a stereo input), however the audio from the computer to radio is handled by an old home made interface I had lying around and at first it did not work on two different serial port numbers, I then opened it up to find the ground wire from the computer side was in fact disconnected from the board, so I had to resolder it back in place, it still did not work then I found that I had not actually plugged the serial to USB adaptor in when I unplugged and reconnected what I thought was it (which was in fact the USB extension cable to the shackcam), after I did plug it in and set the correct COM port a test without the radio connected showed the "TX" LED on the unit light up, plugging it into the KT-8900D confirmed that it shared a pinout with the Leixen VV898 (I had used this interface for APRS experiments with that radio), so ready to transmit.

First attempt the radio keyed up with no audio, my fault as I forgot to plug in the audio lead, second attempt it worked and I had turned the volume pot on the circuit down to its lowest and adjusted it so the receiver, my FT2D, received the audio but not too loud, it needs a bit more tweaking which will be into a dummy load and a test receive on a receiver in another room of the house as the dummy load, though in a metal case, does radiate a little but not too much.

After that I'll try and get some pictures of the local area to have some to send out in these tests and hopefully on air when I get an antenna made and put up, been a while since I have been on 2-meters in general from home other than through repeaters on HTs, and SSTV is something I have wanted to play with for a while

73 de M0WNU

ISS SSTV - 15th to 17th February 2019

Yesterday I stumbled, merely by chance, on what I thought might be a potential SSTV transmission from the International Space Station, which I did tweet about, confirmed by Trevor M5AKA, and I had a look on the Amsat UK website, my home shack radio for 2-meters is still the QYT KT-8900D and the antenna is currently just the 2/70 TX capable magnetic mount scanner antenna, with rubbish thin coax feeding it, on top of a radiator by the window and received the ISS no problem at all.

Today knowing about this, I was able to decode it, thanks to Carl 2E0EZT who mentioned the Robot36 SSTV app in one of his videos on YouTube (a channel I ended up finding out about thanks to Callum M0MCX of DX Commander fame so both are being credited for this), using nothing more than my phone's inbuilt microphone I was able to decode an image from the ISS when it passed over between 1350 and 1400UTC, my first successful attempt at SSTV rx from the ISS, and pleased is an understatement.

When I initially stumbled on the transmission yesterday purely by chance I had mounted the radio onto something to allow air to circulate around it, and also allow it to be raised a little higher, I have the ISS and a few local repeaters along with both 2-meters and 70cm simplex channels all programmed into the radio, and was turning the dial when I heard the transmission, bearing in mind I was unaware that the ISS was overhead at that time so it really was just luck, and on tweeting about it I got my confirmation.

Though I do plan to do some ATV (Fast Scan) I have for a while wanted to play with SSTV but lacked facilities, turns out to receive it all I need is a mobile phone, perhaps the same to TX it too? we'll see

And this is a screencap from Robot36 of what I received today

Not too bad for a first attempt and with equipment that is certainly not the best.

A good reason to get into the hobby, you aren't limited to receiving communications from stations here on good ol' planet Earth, the challenge with the ISS is, of course, knowing when the astronauts are on air and knowing when it will be passing over, and normally you only have a window of a few minutes. in my case it was 10 minutes and I made that count to receive the SSTV image here.

In some cases it is possible to talk to the astronauts but during this weekend the ISS 2-meter station was being used for SSTV so that would not have been possible.

73 de 2E0EIJ