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APRS Experimenters Day on AO-16



APRS Experiment days on AO-16.

The AO-16 command station, Jim White has authorized an APRS experimenters
day on AO-16 to explore the use of the 1200 baud Pacsat for position/
status reporting for distant travelers using common TNC's.  The test
periods will run from 0000 to 2359 UTC on Tuesdays. (Monday nite, and
Tuesday day passes).  APRS experimenters are requested to uplink only on
145.940.  Normal TNC's will NOT work unless modified for Manchester
transmission (a $3 mod);  see TRAKNET in the May/June 1997 issue of the
AMSAT Journal.

The intent here is only to provide a channel for Mobile Travelers or
wilderness position/status reporting (1 or 2 packets per station per day).
Existing users of AO-16 need not fear a deluge of activity, since most
99.9% of APRS users are already connected nationwide via VHF,UHF, HF, and
Internet gateways and have little incentive to mod a TNC for only a few
packets a day.  But HAM truckers, RV'ers, off-shore boaters and cross
country mobile travelers in the wilderness may find this perfect for their
needs.

Obviously, the long term objective is daily coverage, but to test these
concepts, the once a week APRS test day will be used to gather data on the
optimum transmission rate and on the details of making the XOR chip mod on
a variety of TAPR-2 type TNC's.  By using only one day per week now, our
experiments will be focused to when the downlink stations are active...
and any conventional AO-16 users can avoid the 145.94 channel on that day.

The primary need now is for automated AO-16 downlink stations (maybe 3 to
5 across the country) who will link the APRS packets into the rest of the
terrestrial network..  TELNET to 199.227.86.221 port 23 to see the
continuous stream of nationwide APRS packets...  We have one volunteer so
far in Pennsylvania, NR3U.  The AO-16 command team hopes that this
experiment may lead to some good developments in using DSP to automate the
reception of the PSK downlink...  If you have talent in this area, come
join us...

TAPR has established a special interest group for communication among
AO-16/APRS experimenters.  To subscribe, send an email message to
listserv@tapr.org and in the body of the message, put the words: subscribe
ao16aprs Your_Name.  

The idea is to use conventional 2m FM mobile radios and standard TNC's
with the added $3 XOR gate so that any traveling mobile far from home can
configure for transmitting his position/status via AO16 a few times a day.
This makes the Uplink trivial to do for ANYONE going on a long trip...

If you are 1200 baud PACSAT capable, please monitor the downlink on Monday
nights and Tuesday days for any UI frames and capture them.  Until all the
links are in place, post results to the ao16aprs SIG.   Even if you
dont have a PACSAT modem, but do have UHF all mode, you should be able
to hear individual digipeated packets on 437.051 Mhz.  AO-16 comes over
everywhere in the USA between 09:45 and 2:15 both AM and PM local time.
If you DO have downlink and can hear activity on the channel, then you do
not necessarily have to limit your testing to Tuesdays, but simply follow
good amateur practice to avoid interfering with other users if the
downlink is busy.

See  you on the map!   145.94 2m FM up.    437.051 PSK (SSB) down
Bob, WB4APR







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