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MAREX news, ISS Packet active

April 8, 2001

Miles Mann	MAREX-NA 
(Manned Amateur Radio Experiment, North American Division)

Note, the proper call sign of the ISS has not been configured at this
On Sunday April 8, the call sign was NOCALL  (that's a O not a zero).
The call sign will eventually be programmed for R0ISS.
The ISS crew is still making adjustments to the TNC.

ISS UnProto mode

The ISS PMS (Personal Mail System) supports the Digital-repeating mode
called UnProto.  I am not going to get into too much detail about
UnProto, for more information check Amateur radio handbooks and back
issues of Amateur Radio magazine.  Basically UnProto is a way of sending
packet messages without requiring an acknowledgment from the other
station.  This mode is similar to RTTY in that, you can have several
stations in one big QSO at the same time.  Set your UnProto command in
your TNC, on my KAM the syntax is "U CQ V R0ISS".  Then switch to
Converse mode (enter K at cmd: prompt).  Now everything you type will be
transmitted in UnProto Mode.  If the ISS station hears your
transmission, the ISS PMS Digi will rebroadcast your information with a
range of over a 1000 miles.   

Snip from this weeks ISS
Don't let the asterisk * after the call sing fool you.  The call is not
It is NOCALL.  The * means the packet was repeated by the station with
the * after the call sign.

WB4APR-9>APK101,NOCALL*,RZ3DZR [04/08/01 19:55:14]: <<UI>>:
:BLNB     :Its been a long time coming.0Mucho TNX to ARISS!

N4ZQ>ID,NOCALL* [04/08/01 19:55:34]: <<UI>>:
heard wb4apr-9

KB3GGU>SYPX0P,NOCALL* [04/08/01 19:56:55]: <<UI>>:
'h? l  K\]testing via ISS

WB4APR-9>3X5Y8V,NOCALL*,RZ3DZR [04/08/01 19:57:00]: <<UI>>:
'h9Ql  v/]Welcome to ISS APRS!

Snip from a Mir QSO

WF1F>CQ,R0MIR*/V [04/21/93  22:22:09]: <UI>:
hi Tim can you work OSCAR 13?

N8DEU>CQ,R0MIR*/V [04/21/93  22:22:30]: <<UI>>:
Hi miles, yes what freq?

WF1F>CQ,R0MIR*/V [04/21/93  22:22:40]: <UI>:

The UnProto mode does not guarantee you message will ever be heard, but
if the ISS Digi does rebroadcast your line of text, then you can be
assured that someone saw it.  The line of text you send will be repeated
with an Asterisk after it, "R0ISS*/".  If you do not see the Asterisk,
then ISS did not hear your packet.  UnProto does have its drawbacks, but
it is much more efficient to use on ISS than the Direct two-way connect
method. Full two-way packet connects via the ISS PMS are not recommended
because they use up too much resources and excessive "Retires".  Before
you try Unproto on ISS, I recommend that you practice on a Terrestrial
Digi first before attempting to use the ISS station for Digi-repeating.
If you make a few UnProto calls and do not get any echoes back from ISS,
it is probably because UnProto is turned off or because of a collision. 
Occasionally the System Operators may turn off Unproto (Digi = OFF) to
improve the MailBox traffic flow.  The Mailbox access should always have
top priority over other traffic. Also there is a good time and a bad
time to use the UnProto mode with ISS PMS. 
Do not use UnProto when:
1. The ISS crew is operating in Voice mode.
2.  When the ISS PMS is connected to another station that is actively
sending/receiving information from the Personal Message System (PMS). 
Any Index packets going to the R0ISS-1 address.
The only real safe time to use UnProto, is when the ISS PMS is in its
2-minute time-out mode.  This time-out is caused when the station
connected to the ISS PMS is out of range and cannot log out of ISS.  No
one can log into PMS Mail box (R0ISS-1) until the connected station
times out.  Time-outs are the best time to use UnProto.  Before using
UnProto, monitor ISS's down link to see who is using the PMS Mail box
port "R0ISS-1".  If you do not seen any Index packets from ISS PMS to
the ground station using to the "R0ISS-1" port for 60 seconds, you can
assume the connected station is out of range of the ISS PMS and its
"UnProto time".
The shorter the Unproto sentence, the greater your success of a PMS
repeat.  Long sentences may get clobbered by other stations.  If you are
in the middle of an Unproto QSO and you see someone connect to the PMS
Mail box "R0ISS-1", you should end your Unproto QSO and let the Mail box
users have access to the PMS.

Previous Testing of Two-way Connects via Mir:
In 1993 WA2GSY in New Jersey (now W2KQ) and I WF1F in Boston made
arrangements to test the efficiency of FULL-TWO-WAY packet connects
verses Unroto messages.  Unfortunately I have lost the original logs
from the test, but I do clearly remember the results.  We made
arrangements for the Mir Amateur Radio station to move to a private
channel for a weekend.  Then Joe and I attempted a Full-TWO-WAY packet
Digi connect via the Mir PMS on a perfectly clear channel.  The orbit
was a perfect pass, traveling from Texas to Maine.  The 10-minute pass
had good elevation.  Both of our stations were similarly equipped and
running high gain antennas with approximately 1200 watts ERP of transmit
power each.  At the beginning of the pass, we sent a few Unproto
packets, and then Joe issued the full two-way connect to my station. 
After the initial log-in we each sent each other two simple lines of
ASCII text and then logged out.  Now you must remember we had a
perfectly clear channel.  There were NO other stations on frequency
because we had moved the PMS to a private channel.  There was no
interference from any ground stations.
It required over 4 minutes for us to exchange the 2 lines of text.  The
total number of packet transmission from all three transmitters was over
200 packets. Every packet, which I sent, had to be heard, acknowledged
and retransmitted by the Mir PMS.  The same packet was then sent to
WA2GSY and had to be heard and acknowledge.  The acknowledgment from
WA2GSY then had to go back to Mir and Acknowledgement had to be
re-broadcast from Mir back to my TNC.  Four transmission are required
for each original packet.  However since my station in Boston cant hear
when Joe's system in New Jersey was transmitting, there were dozens of
packet collisions. These collisions are what causes the efficiency of
two-way packet to drop.  With a full two way connect each packet sent
must be acknowledged.  This causes a tremendous amount of over head in
this particular satellite configuration.  The efficiency of full two way
connects via Mir is less than 10% on a perfectly clear channel.  Now if
you add in the normal amount of traffic to the Mir public channel, you
can see that full two way connects are a complete waist of time.  The
efficiency of Unproto on the other hand is greater than 50%.  And
Unproto is more band friendly.
The existing design of the TNC on ISS does not allow us to filter out
the difference between Unproto and Two-way connects its just all or
nothing.  So we need to rely on your courteous corporation and for
people to help spread the word on the correct operating procedures.

Good luck and let's be courteous to everyone.

Remember, Only 1 station can connect to ISS's PMS at a time, and try
avoid using UnProto when someone is actively using the PMS Mail Box.

Space Station Alpha  gets a new Amateur Radio call sign:
The ISS ALPHA is keeping the international flair by hosting several
amateur radio call signs from around the world.  So far the ISS ALPHA
has four calls signs from three different countries, Russia, USA and
Germany. Also each of the crewmembers of expedition 1, has their own
personal Amateur Radio call sign.  The newest call sign is now R0ISS  (R
Zero ISS).  The new call sign will become the official call sign of the
Space station.  You can expect the ISS crew to be using this call sign
on both voice and packet operations.  The new Club call signed was
issued by the Russian government on December 12, 2000.
Russian Module call sign:	RZ3DZR / R0ISS
Other club call signs ISS used: NA1SS, DL0ISS  and ALPHA

Ground Station Link:
What will you need to Hear the ISS ALPHA Amateur Radio 2-meter Station.
That's a tricky question because there are good orbit pass and poor low
orbit passes.  On a good 45 degree orbit pass, since the ISS ALPHA is
only 250 miles high, you will be able to hear the 2-meter signal from
the space station with a very small antenna (0 dBd  to  minus 12 dBd
(rubber duck)).  During a very low orbit passes under 20 degrees you may
need a much larger antenna.
The Amateur Radio station on ISS ALPHA will be transmitting in the
satellite 2-meter band (ITU 144.000 - 146.000 mc).  I have listed a
frequency chart below.  The ISS ALPHA transmitter power output is
approximately 3 watts, into a pair of co-phased vertical antennas rated
at minus 3 dBd.  There is one antenna on each side of the Service
module.  Both antennas are then connected to a power divider to split
the transmit power evenly between the two antennas.  The co-phased
installation provides a good transmit and receive patter, with very
little blocking of the signals by the bulk of the space station it's
self. I do not have the coax loss values at this time.  This combination
of power and antenna gain will provide an ERP rating of  approximately
1.5 watts.  The 1.5-watt value is not that bad, many stations have
reported hearing the ISS crew talking to pre-arranged schools with the
ISS Amateur Radio station and the signal reports were very good.  If you
only have a zero dBd gain antenna and a police scanner you will still be
able to hear the ISS ALPHA on some good orbits.  I have even heard ISS
with a HT and Rubber duck (not recommended for quality reception).
(note:  if your antenna is rated in dB rather than the correct dBd
value, subtract 3 to convert the dB value to the correct dBd rating. 
The higher the dBd rating, the better the antenna.)

Suggested receiving station:
Casual listening for ISS ALPHA and Mir
2-meter vertical or scanner antenna (0 dBd or better)
Police scanner or amateur radio with the ability to receive in the 144 -
146 mc or MHz range, FM mode.  Antenna cable should be a low loss RG-8
style cable less than 100 feet long (RG-213 best choice).  You will not
need to mount the antenna very high, just try to get above the roof
ridgeline.  And of course you will need to find / buy a satellite
tracking program.  I recommend the InstantTrack 1.5. It's a simple easy
to use program, which can be purchased from Amsat.

ISS ALPHA frequencies:
The Amateur Radio frequencies for ISS ALPHA have been posted.

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	144.488.5	-1.314
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
Chan	Receive	Transmit	Offset (Meg)
4	145.802.5	145.988.5	+0.186
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	145.198.5	-0.604
8	145.800.0	145.200.0	-0.600
9	145.798.5	145.202.5	-0.596

Usage Example:
Lets assume ISS ALPHA is approaching for a good 10 minute over head
pass, running Packet.  When ISS ALPHA comes over the horizon the Doppler
frequency error will initially be 3.5k plus 145.800 + 3.5 = 145.803.5. 
This means the frequency ISS ALPHA will appear to be transmitting on is
145.803.5.  Set your radio to channel #4 for the first 3 minutes of the
pass (145.802.5 is close enough).  Then for the next 3 minutes use
channel #5 and for the last three minutes use channel #6.  Follow the
same procedure for Voice operations.  Since we are using the Mode FM, we
do not have to have our Transmit and receive frequency exactly on
frequency. We can be off frequency 1-2khz and still get reliable Voice
and Data.  The MAREX-NA team has been using this procedure for 10 years
with excellent results.
Setting your Receive frequency:

QSL card:
A QSL card is a post card, which you can request to confirm you made a
two-way or heard the crew on the Amateur Radio band.  The QSL procedure
for ISS ALPHA is under development, please check the AIRSS web pages for
the latest updates and QSL procedures for ISS ALPHA.

New MAREX Web page
Please check out our new MAREX web page with updates on the new
SpaceCam1 SSTV project

Copyright 2001 Miles Mann, All Rights Reserved.  This document may be
freely distributed via the following means - Email (including
listservers), Usenet, and World-Wide-Web.  It may not be reproduced for
profit including, but not limited to, CD ROMs, books, and/or other
commercial outlets without prior written consent from the author. 
Images received from the MAREX-NA SSTV system on the Russian Space
Station Mir are considered public domain and may be freely distributed,
without prior permission.


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