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Mobile/Handheld HAM Travelers



The launch of PCsat on 1 Sept 2001 will represent a new direction for
amateur satellite communications.  PCsat will offer distant travelers the
ability to send and receive satellite message traffic and to report their
position and status from anywhere on earth using only a handheld HT.

No HAM traveler heading to the wilderness should leave home without his
shirt pocket APRS HT or other portable packet station.  This message is
only an alert to anyone planning expeditions after 1 Sept to be thinking
about the smallest PACKET station you might want to pack with you.

PCsat will use conventional APRS packets at 1200 or 9600 baud and is
designed to work with HTs or mobiles on an OMNI antenna.  This focus, on
the HT or mobile user is a first for the Amateur Satellite Service.  But
such operations will also incur additional responsbilities on users.

PCsat, having a specific mission, will take an unusual step in the amateur
satellite service by publishing user station requirements and asking users
to adhere to those requirements.  THis is necessary to assure consistent
performance for everyone.  Anyone is welcome to use PCsat, but only if
they adhere to the user station power limits and modes of operation as
published.  Bulletins from the satellite will inform users of current
requirements, but in general the following will probably be the
recommended standard operating practice:

UPLINK  STATIONS         ERP  BAUD  PACKET RATE (one packet per)
------- ---------------  ---- ----  -----------------------------
145.825 HT's and 5W QRP   10W 1200  every 2 minutes while in view
435.250 Mobiles and 50W  100W 9600  every 2 minutes while in view
Either  HAM Demos        tbd  both  tbd            

Remember, the only objective of APRS satellites is to get at least ONE
position packet (maybe 2) digipeated during a pass and also any single
outgoing or incoming message packet.  In this manner, it should be able to
support hundreds of travelers.

The final recommended duty-cycle for users will be determined only after
several weeks or months of experience.  As usual, HAM demos and special
events will always be afforded a higher priority.  Very special travelers
may also be given special access and should submit a TRIP-PLAN to the 
PCsat ground team prior to planned operation.

Remember, this can work with a ground station as simple as the Kenwood
TH-D7 HT in your pocket, so make your travel plans with this in mind.
Steve Dimse K4HG is putting together a special PCsat WEB page like the
one he operates for ISS.  See references below for more info...

But none of this works well, unless there are dedicated IGate stations on
the ground monitoring the 145.825 downlink in each footprint.  COverage in
the USA and Europe will be easy.  But finding dedicated amateurs about
every 1000 miles in other countries with permanent Internet access will be
more difficult.  If you live in these far away places, you might begin to
consider joining the network to support your fellow hams.

To see the current world map of APRS connectivity go to
http://www.aprs.net

WB4APR@amsat.org, Bob

ISS-APRS FAQ:       http://web.usna.navy.mil/~bruninga/iss-faq.html
PCsat Design        http://web.usna.navy.mil/~bruninga/pcsat.html
APRS SATELLITES     http://web.usna.navy.mil/~bruninga/astars.html

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