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[aprssig] Need GO-32 APRS Users

Bill Diaz william.diaz at comcast.net
Thu Oct 18 20:09:28 UTC 2007

  I have been developing ASatLogger, a stripped down version of ALogger
specifically for use by SatGates.  It communicates with TNC/D7/D700/D710 via
the serial port, can relay valid APRS packets to the APRS-IS and log packets
to disk.  It handles KISS or standard TNC2 display format.  Hopefully, it
will be released this coming weekend.

I have ASatLogger communicating with a D7, setting frequency, step, HBAUD,
TXA/RXB, Ignore DCD etc.  Currently working on cmd files for G0-32 and have
most of it implemented.  It does not do automatic doppler shift, but the
user can manually enter the DW or UP commands to shift the freq using either
the current frequency step or memory channels.  It includes an editor to
edit cmd or TNC files.

Not all of the D7 commands have been documented, and some which have been
documented are incomplete, or can be somewhat misleading.  Same for the
D700.  I have no idea if the D710 supports all of the known D700 commands or
if it supports any additional commands.  Sure would be nice if Kenwood
published the full command set.  Wishful thinking.

I suppose a simple automatic doppler shift routine for OMNI antennas could
be implemented using only a user settable time interval and sending UP or DW
commands at step intervals of Interval/3 or Interval/4 or Interval/5 etc.
The settable time interval would be a max of about 15 minutes and a minimum
of 4 minutes or so.  When the timer starts, you issue periodic DW or UP
commands at each step interval. Will take some playing around, but it should
be possible to come up with a method to do this semi-automatically.  The
user would only need to choose the interval by subtracting calculated AOS
time from calculated LOS time.  With a little more work, it could be done
using a file containing AOS and LOS datetimes for your location.  This would
permit automatic operation, provided the application was supplied with the
correct AOS and LOS datetimes.  Will see about adding this to ASatLogger
when time becomes available.

ASatLogger also includes a TNC Virtual Access Server.  Multiple remote users
can access the serial port using most APRS client applications or TELNET
applications such as Hyperterminal.  Only users with the proper password can
send data to the serial port however.  I have connected to the ASatLogger
TVAC Server remotely using UiView's serial port and a freeware HW Vitrual
Serial Port application available from http://www.hw-group.com/index_en.html
.  UiView complained a bit, but it worked.  ASatLogger does not currently do
flow control between the serial port and TNC/D7/D700/D710 however.  

ASatLogger was developed due to Bob, WB4APR's request for a simple, basic
SatGate application for use with GO-32 and ECHO.  ALogger was just too
complex for casual users who are unfamiliar with APRS.  See
http://www.billdiaz.dynip.com for details.

Bill KC9XG

>-----Original Message-----
>From: aprssig-bounces at lists.tapr.org 
>[mailto:aprssig-bounces at lists.tapr.org] On Behalf Of gerheim at cox.net
>Sent: Thursday, October 18, 2007 13:12
>To: bruninga at usna.edu; TAPR APRS Mailing List
>Subject: RE: [aprssig] Need GO-32 APRS Users
>It's theoretically possible to write software to automatically 
>compensate for the doppler, and pipe the downlink to a server.  
>If someone out there has the time, I could explain how to do 
>the tracking, doppler, and talk to the D7.  
>Right now, I'm working full time, and attempting 6 semester 
>hours of graduate coursework in math (real theorem-and-proof math).  
>It seems like half of each pass is lost if you use a fixed 
>doppler shift.  
>---- Robert Bruninga <bruninga at usna.edu> wrote: 
>> > I've had the satgate up for a couple days, 
>> > and haven't found any APRS traffic.  
>> Al, hang in there.  It's the chicken/egg syndrome.  You're now
>> the 3rd Igate that I know of and the only one on the east coast.
>> There are many pieces of this puzzle:
>> 1) The satellite mods (took from may to Oct)
>> 2) The FINDU mods (in work)
>> 3) Getting enough permanent satgates (in work)
>> 4) Getting the tracking down (only Wash DC table is done)
>> The good news is that this will be a permanent APRS capability,
>> that is hopefully more reliable than ARISS, or PCSAT-1.  RAFT,
>> PCSAT-2 are finished and ANDE only has one more month.  So tht
>> is why we are excited over the long term potential for GO-32.
>> It will take the users a while to realize how easy it is to use.
>> Thanks!
>> Bob, Wb4APR
>> > 
>> > FN41di.  
>> > 
>> > I have the freq set for +5kHz doppler during the day, and for 
>> > some of the evening passes, I manually adjust it during the
>> passes.  
>> > 
>> > 
>> > --
>> > -Al Gerheim, K1QN
>> > 
>> > HP-49G+ Software Page:
>> > http://members.cox.net/above
>> > 
>> > _______________________________________________
>> > aprssig mailing list
>> > aprssig at lists.tapr.org
>> > https://lists.tapr.org/cgi-bin/mailman/listinfo/aprssig
>> > 
>> _______________________________________________
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>-Al Gerheim
>HP-49G+ Software Page:
>aprssig mailing list
>aprssig at lists.tapr.org

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