By Miles Mann WF1F,
MAREX-NA (Manned Amateur Radio Experiment, North American Division)
The testing of the Amateur radio station initially took place while
ISS was over Russia during two prearranged test orbits.
Pass | Time |
---|---|
1 | 6:17-6:25 UTC (9:17-9:25 MSK) |
2 | 8:53-9:03 UTC |
The Amateur Radio station on ISS consists of a commercial grade hand held radio called a HT. The radio operates in the ITU satellite portion of the amateur radio 2-meter band 144.000 - 146.000. The exact frequencies used during the test are of course a closely guarded secret, however when testing is completed the radio will be placed on one of the published public channels. The ISS Amateur Radio station is not currently open to the public at this time.
Station #1:
Transceiver, Oscar Class 180 watts RF FM.
Antenna 20 element Circular polarized, gain approximately 9+ dBd,
Approximate ERP 1440 watts
Station #2:
Transceiver, Mobile Class 50 watts RF FM.
Antenna, Vertical collinear 7 meters in length, gain aprox 6 dBd,
Approximate ERP 200 watts.
The first pass test used the big station #1. This orbit was a low orbit pass, only getting 28 degrees above the horizon, and its closest approach to the station was just over 700 kilometers. Cosmonaut Musa U2MIR was to be the first person in the club station to make the contact, however Musa was a little late for the schedule. So the task fell upon Sergej Samburov RV3DR to make the first contact with ISS via Amateur Radio. (Sergej Samburov is also the manager of the club station at RSA and the club station on ISS.) The initial contact took place on schedule and the microphone was quickly passed around the room to the other present, including Vladimior Zagainov, UA3DKR and Eugene Labutin, RA3APR. The audio and signal quality were excellent, we use the term DFQ, Darn Full Quieting. The contact lasted 10 minutes as the space station traveled from horizon to horizon. A strong signal was maintained during the whole 2-way conversation.
The second test orbit used the lower power station with a smaller antenna. This orbit was also a low orbit pass, only getting 28 degrees above the horizon, and its closest approach to the station was just over 700 kilometers. On occasions you may get an orbit directly over your house and the station will be only 400 kilometers away. The signal quality was noticeably lower and there was considerable noise on the signal during the beginnings and end of the 10 communications pass. The difference in signal strength was primarily because of the lower gain antenna on the club station. The bigger the antenna, the more signal you can pull in. The ISS crew and club station member enjoyed another 10 minute conversation and declared the initial voice testing of the Amateur Radio station a success. Cosmonaut Mikhail Turn was present during the testing. It will be Mikhail job to install the new Amateur Radio antenna on ISS during his expedition 3 ISS mission in 2001.
After the test Sambrov and I discuss the signal quality and compared
it to the Russian Space station Mir. The Mir station had a slightly
better antenna and it had the ability to select different transmitter power
levels with the Kenwood TM-733 settings of 5,10 and 50 watts output.
To help conserve power, the Mir station was usually kept on the 5 watt
setting. The signal quality results of this ISS test were similar
to signal quality reports from Mir, when Mir was using the 5-watt setting.
The ISS transceiver has an estimated ERP transmitter value of 1.5 watts.
These results are still preliminary. However, it looks like stations
with a zero gain antenna will be able to hear ISS and will be able to establish
2-way connections on good close orbit passes. Sergej then said, there
are plans to upgrade the antenna system on ISS during expedition #3 mission,
with an antenna system specifically designed for the amateur radio bands.
There are also tentative plans to upgrade the
transceiver on ISS to a 50-watt class transceiver (pending many approvals).
For more information on this mission please check the NASA web pages.
http://spaceflight.nasa.gov/index-n.html.
Name | Title | Call Sign |
---|---|---|
William Shepherd | Expedition commander | KD5GSL |
Yuri Gidzenko | Soyuz commander | (pending) |
Sergei Krikalev | flight engineer | U5MIR |
Russian Module call sign | RZ3DZR | |
Other club call signs ISS used | RS0ISS, NA1SS and DL0ISS ALPHA |
Worldwide downlink for voice and packet | 145.800 |
Worldwide packet uplink | 145.990 |
Region 1 voice uplink | 145.200 |
Region 2 & 3 voice uplink | 144.490 |
You will need to dig out the manual for your radio and program in the
following frequency combinations. Note that some of the older FM
mobile and Walkie-talkie HT style radios over 15 years old may have some
difficulty in saving these combinations into memory. The channels
listed below will help you compensate for the speed of the space station,
called Doppler. If the smallest channel step your radio supports
is 5k, then only program in channels 2, 5 and 8. If your radio
supports the smaller 2.5k channel step, then program in all channels
listed. After you have determined your smallest channel step supported
by your radio, then program in the channels. You can either use the
procedures for storing ODD-Splits or you can reprogram your repeater off
set for each of the channels and then save the new combination in a new
memory location. This channel procedure has been successfully used on the
Mir Amateur Radio program for years and is the choice of usage for school
schedules (you do not want to fiddle with VFO's during a 10-minute pass).
I also recommend you program in all channels, no mater what part of the
world you live in. The World Map ISS ALPHA location display used
by the ISS ALPHA crew is not located next to the Amateur Radio station.
Voice operations Region 2 & 3 (North and South America and Pacific)
Chan | Receive | Transmit | Offset (Meg) |
---|---|---|---|
1 | 145.802.5 | 144.487.5 | -1.315 |
2 | 145.800.0 | 144.490.0 | -1.310 |
3 | 145.798.5 | 144.492.5 | -1.306 |
Packet operations Regions 1, 2 & 3 (Europe, North and South America
and Pacific)
Chan | Receive | Transmit | Offset (Meg) |
---|---|---|---|
4 | 145.802.5 | 145.987.5 | +0.185 |
5 | 145.800.0 | 145.990.0 | +0.190 |
6 | 145.798.5 | 145.992.5 | +0.194 |
Voice operations Region 1 (Europe)
Chan | Receive | Transmit | Offset (Meg) |
---|---|---|---|
7 | 145.802.5 | 145.197.5 | -0.605 |
8 | 145.800.0 | 145.200.0 | -0.600 |
9 | 145.798.5 | 145.202.5 | -0.596 |