ISS Talking On Field Day Weekend (Maybe)

Int'l Space StationMiles Mann, WF1F writes on BARS mailing list:

This weekend it may be possible to listen to the Crew on board the ISS. And if you are a licensed Ham, you may even get a chance to talk to them directly by ham radio, too.

Voice Tips:

Packet Tips:

The Space Station will be transmitting on 145.800 FM. If you have a proper licens you can try to call them using the posted Uplink channel. The uplink channels are different depending on what part of the world
you are located in.

Channel 1 145.800.0 RX 144.490.0 TX Voice North America
Channel 2 145.800.0 RX 145.990.0 TX Packet (Worldwide)
Channel 3 145.800.0 RX 145.200.0 TX Voice (Region 1Europe, Africa)

Audio from the 2002 field day links with Susan Helms on ISS

From the Amsat BBS June 22, 2004

by Scott H. Stevens / N3ASA

Astronauts aboard the International Space Station may participate in Field Day operations this year. Mike Fincke, KE5AIT, and Gennady Padalka, RN3DT, may participate in Field Day activities as time permits.

Fincke should be operating as NA1SS, 1 Alpha, ISS. If Padalka can participate then he should sign RS0ISS, 1 Alpha, ISS.

ISS Ham Radio Project Engineer Kenneth G. Ransom, N5VHO, sent Field Day operating instructions and pass times to the ISS support team at Johnson Space Center for relay to Fincke. Best pass times sent to Mike are for June 27 and include:

07:53 – 08:11 UTC Southern & NE U.S.
09:27 – 09:47 UTC Western U.S.
11:03 – 11:23 UTC Northwest U.S.
14:15 – 14:35 UTC Northeast U.S.
15:51 – 16:11 UTC Central U.S.
17:27 – 17:43 UTC Southwest U.S.

The plan is for Fincke to be on voice using the standard ISS voice frequencies for contacts in ITU region 2 of 144.49 up and 145.80 down in the FM mode. If Padalka participates, he will also operate on the same 2 meter frequency set and they will probably trade off on passes.

The prospect of two operators being available and operating simultaneously is possible since ARISS now has 2 radios on board. One of them is a dual band and that makes activation of another band possible though not guaranteed. If we are fortunate enough to have 2 operators on at the same time, one of them would operating on 437.55 simplex in the FM mode while the other is on the standard 2 meter FM split voice frequency. Keep in mind that the Doppler shift in the 70 centimeter band is significantly greater than on 2 meters.

Doppler will be the biggest challenge for earthbound hams trying to work ISS on 70 cm. The Doppler on 70 cm is plus or minus 10 kHz. Most radios include 5-kHz tuning steps, and to work ISS on voice you will need to get within 3 kHz of the ISS receiver frequency. Setting up memories on a 5kHz stepped radio would require 5 memory channels. Start with channel 1 at the beginning of the pass and proceed to the next as the pass progresses.

TX Channel RX Channel Doppler
1 437.540 437.560 +10
2 437.545 437.555 +5
3 437.550 437.550 0
4 437.555 437.545 -5
5 437.560 437.540 -10

Ideally, you would be able to have tuning steps of 2 kHz and the table would look like this:

TX Channel RX Channel Doppler
1 437.540 437.560 +10
2 437.542 437.558 +8
3 437.544 437.556 +6
4 437.546 437.554 +4
5 437.548 437.552 +2
6 437.550 437.550 0
7 437.552 437.548 -2
8 437.554 437.546 -4
9 437.556 437.544 -6
10 437.558 437.542 -8
11 437.560 437.540 -10

As with any amateur radio operation aboard the ISS, the crew gives of their free time to participate and as such may not be available on every pass or more pressing events may preclude any participation at all. It is planned that if the crew is unable to participate that the packet station will be on and available for ground stations to work each other via the packet digipeater using ARISS as the alias for the callsign in UNPROTO mode using 145.99 up and 145.80 down.

Keep in mind that an EVA is scheduled just a few days before Field Day and the crew will still be in the process of getting back to a normal schedule when Field Day is in full swing.

73 & good luck on Field Day!
Scott H. Stevens / N3ASA


Marexmg Web page

Information on the crew’s activities aboard the Space Station, future launch dates, as well as Station sighting opportunities from anywhere on the Earth, is available on the Internet at:

73 Miles WF1F MAREX-MG

Until we meet again


Leave a Reply