Slow Scan Television from the ISS this weekend…

April 10, 2015 | Amateur Radio, Amateur Satellite, SSTV | By: Mark VandeWettering

Note: This post was adapted by an email that I sent out to our ham radio club.

If anyone is interested in a fun little ham radio related activitytonight, you can try to receive slow scan television from the International Space Station this weekend. I haven’t done this in a while,but I think I’ll give it a try and see what I can come up with.

You can read about this event here:

AMSAT UK on the upcoming ISS event

They will be on 145.800Mhz (in the 2m band).

The way I usually “work” these is to use one of my HTs. A better antenna than the stock one is usually good (a longer whip, or even a yagi) but you might just see what you can here with the stock antenna. The ISS transmits with 25 watts of power, which is usually pretty easy to hear. I have a set of earphones that I hook with a splitter. One half goes to my earbuds, the other to a small digital audio recorder I have. Turn the squelch on your radio off so you can here the signal when it is weak. You may find that moving your antenna round will help a bit, so monitor with your earphones. Don’t be shocked if you don’t hear the ISS right at the rise time: it has 3 minutes of dead time between transmissions, which take about 3 minutes to send. It sounds a bit like a ticking of a clock, with a whistle in between, if you click this link, you can hear what it sounds like:

I like to record the audio, then play it back into my Windows PC and use the MMSSTV program, but you can actually go completely low tech and try an inexpensive iphone app, held up to the speaker of your HT. I use

Black Cat System’s SSTV program for the iPhone/Ipad

which works okay, not amazing. If you are out doors in a windy or noisy location, your image won’t be as good this way: the bg noise will cause interference.

To help out, I computed a set of rise/set/max elevation tables centered on San Francisco. If you live close, you can probably use these times. If you live in other parts of the country, you might try looking at the Heaven’s Above website. Select “Passes to include” to be all, and enter your location in the upper right. The table below was calculated by my own software.

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Rise time           Azi    Max Elev Time        Elev  Set time             Azi
--------------------------------------------------------------------------------
2015/04/11 16:24:33 178.90 2015/04/11 16:28:52   9.27 2015/04/11 16:33:10  74.10 (Local Time)
2015/04/11 23:24:34 178.90 2015/04/11 23:28:52   9.27 2015/04/11 23:33:11  74.10 (UTC)

2015/04/11 17:59:18 232.14 2015/04/11 18:04:47  76.70 2015/04/11 18:10:17  49.52 (Local Time) [1]
2015/04/12 00:59:18 232.14 2015/04/12 01:04:48  76.70 2015/04/12 01:10:17  49.52 (UTC)

2015/04/11 19:36:48 276.47 2015/04/11 19:41:38  13.93 2015/04/11 19:46:28  40.34 (Local Time)
2015/04/12 02:36:48 276.47 2015/04/12 02:41:38  13.93 2015/04/12 02:46:28  40.34 (UTC)

2015/04/11 21:15:06 309.66 2015/04/11 21:19:13   7.29 2015/04/11 21:23:21  47.92 (Local Time)
2015/04/12 04:15:06 309.66 2015/04/12 04:19:14   7.29 2015/04/12 04:23:21  47.92 (UTC)

2015/04/11 22:52:10 319.85 2015/04/11 22:56:52  12.34 2015/04/11 23:01:34  78.97 (Local Time) [2]
2015/04/12 05:52:10 319.85 2015/04/12 05:56:53  12.34 2015/04/12 06:01:35  78.97 (UTC)

2015/04/12 00:28:22 312.09 2015/04/12 00:33:48  58.58 2015/04/12 00:39:14 122.75 (Local Time) [3]
2015/04/12 07:28:22 312.09 2015/04/12 07:33:49  58.58 2015/04/12 07:39:15 122.75 (UTC)

2015/04/12 02:05:15 289.69 2015/04/12 02:09:49  11.95 2015/04/12 02:14:23 174.60 (Local Time)
2015/04/12 09:05:16 289.69 2015/04/12 09:09:50  11.95 2015/04/12 09:14:24 174.60 (UTC)

[1] Probably the easiest pass, the ISS passes almost straight overhead,
should be loud and easy.

[2] A low night time pass, but the ISS should be visible to the naked eye.

[3] Another night time pass, but too late for the ISS to catch any
sun. 58 degrees is a good pass, the second one.

If I get any good images, I’ll send them out next week.