[Date Prev][Date Next][Thread Prev][Thread Next] - [Date Index][Thread Index][Author Index]

Re: APRS School MIR pkt Experiment

This week,  As part of an ongoing low power, low duty cycle APRS School
experiment via MIR, we have been using only an HT (with built in TNC
and display) and stock rubber duck antenna to demonstrate exchange
of APRS messages and position reports via the MIR packet system.  THis has
been done on a not to interfere basis to show the potential for emergency
position/status reporting capabilities for expeditions carrying only an
HT.  Since the semester ends today, now's a good time to report results.

This test has been made possible by the new Kenwood data HT with built in
APRS messaging and GPS position reporting capabilities.  Even though our
unscheduled tests also coincided with the activation of the SSTV
experiments on MIR, the HT is also plug compatible with the Kenwood VC-H1
handheld SSTV system, so with only two shirt pockets of equipment we have
been able to demonstrate both modes while standing in the school parking

Here are some of the bulletins, messages and status reports we received
(and sent) on the HT (Our call is W3ADO-6):

R0MIR>CQ:Hello from the MIR Crew!
N3JLQ>APRS,R0MIR*::W3ADO-6  :Hello MD from Sweden, ME
KD4CGA>CQ,R0MIR*:: W3ADO-6  :(msg text lost)
WA4BWB>APRS,R0MIR*::This is a test msg from Lynchburg,VA
WD4PFO>ID,R0MIR*:Greetings from North Carolina
W3ADO-6>APK001,R0MIR*::WD4PFO   :Rgr!

We noticed that we could also transmit from the HT and be digipeated
occassionally if we waited for a quiet period and pressed the XMT key a
few times.  So clearly 5 watts into a -6 dB rubber duck will work to
the orbiting space station occassionally (or frequently in the
absence of QRM).

Our MIREX WEB page is constantly monitoring MIR and capturing all
packets whenever the MIR PMS is on.  It has experiencied some crashes so
we lost some data, but it is now fixed and is showing the correct times...
If you check now (before there are 8 more passes) the last pass will
be visible as the pass saved at 2001z.


We noticed several other UI frames captured by our WEB page that did not
get captured by the HT.  THis is because the Kenwood HT (using its
internal dispaly and not a laptop) will only capture and display APRS
positions, status and message formats, not all packets.

This message is not meant to encourage random transmission of UI packets
via MIR, but to report on the completion of a brief school test.  If you
get one of these new HT's, put it in APRS mode, and put it on 145.985 and
see if you capture anything when MIR flies over... Anyone can receive....
The rest of the time, put it on 144.39 and you can communicate nationwide
with it... via the internet linked APRS system.

 de WB4APR, Bob

Via the sarex mailing list at AMSAT.ORG courtesy of AMSAT-NA.
To unsubscribe, send "unsubscribe sarex" to Majordomo@amsat.org