With my recent success at getting a packet through the space station, and recognizing that my non-directional J-Pole antenna wasn’t going to result in enough downlink signal for spacecraft work (let alone enough for uplink), I ordered a 2m/70 cm dual Yagi from Arrow Antennas and a short run of coax to go with it.
I got the antenna and then learned about the ISS activity planned for last weekend. Slow Scan Television was going to be broadcast from the Space Station on Saturday and Sunday in commemoration of the 40th anniversary of the Soyuz Apollo Docking mission in 1975. That and the ISS crew would be doing a Q&A via amateur radio with students attending the Moon Day/Frontiers of Flight Museum in Dallas, Texas on Sunday.
I checked n2yo.com for passes on both days and found quite a few, including some with fairly high elevation. I jotted them into my notebook, including the start and stop azimuth and the max Elevation angle and its azimuth. I would need those to manually point the antenna, which I attached to an old camera tripod.
I also bought a SSTV app for my iPhone, so I could demodulate and view the images.
And, since my MacBook (like most) lacks a separate line-level input, I dug up my old M-Audio MobilePre USB from my old Podcasting days to connect between my radio (a Yaesu FT-7800) and the computer,
The last piece to the puzzle was learning that I could use OSX’s Quick Time App to record Audio AND listen to it at the same time, so I had everything I needed to both try and view SSTV images on the fly as well as, if needed, try decoding them from the recorded audio if necessary after the space station pass was long over.
Early Saturday morning I got everything set up and connected in our front yard and pointed the antenna toward the horizon, tuned the radio to 145.800 MHz (ordinarily the station transmits digital data at a different frequency, but I think this is coming from dedicated equipment in the Russian segment of the station) and turned off the squelch. A wash of static erupted and I waited for the real time tracking display from n2yo.com to indicate the station was rising above the horizon. I started recording.
Static, static and more static for what seemed like forever. I carefully increased the antenna elevation angle and steered to the side approximating where n2yo.com said the station should be.
Still more static, and then all of a sudden silence. At first I thought something had broken. Then I noticed the RX level on the radio was pegged at full. I remembered the scene from Contact where they budged the antenna off axis to confirm the other-worldliness of the signal and decided to do the same. I swept the antenna a little to one side and static rose in the receiver. I swept it back and the receiver was quiet again and still receiving an incredibly strong signal.
That was the 1346 UTC pass on July 18.
A little checking on Twitter confirmed I wasn’t the only one receiving strong unmodulated carrier.
The next pass, the 1523 UTC pass, had the same strong unmodulated carrier but then a voice! A voice! A very Russian voice. I had heard my first Cosmonaut from space, and I was thrilled. The recording is here.
The next pass was, at 1659 UTC, was going to be the one with the chat between the space station and the students, and although the elevation was going to be quite low for me, 20 degrees, I was. going to give it a shot.
It worked really well, and I got to hear… (to be continued)