GO-32 APRS衛星誕生


● (No.546) GO-32 APRS衛星誕生 (2007年9月16日)
 ---------------------------------------------

GO-32 が、新しく APRS衛星 として生まれ変わりました。
9月16日に広報され、自局においては 9月20日にデジピートに成功しました。

GO-32
19:18-19:33 JST, 20 Sep 2007
10:18-10:33 UTC, 20 Sep 2007
Max ele 55 deg

UNPROTO APRS VIA 4XTECH
Up 145.850, Down 435.225, 9600 bps, FSK
TS-790S (KENWOOD)

4XTECH-12>BEACON [09/20/07  19:18:52] <UI R>:
>Thu Sep 20 10:19:15 2007 :UTC| Gurwin Techsat1B (V9.87)   
4XTECH-12>BEACON [09/20/07  19:18:53] <UI R>:
Gurwin Techsat1B's BBS is active  again,(version 9.87 beta) .
4XTECH-12>BEACON [09/20/07  19:18:53] <UI R>:
u wellcome! 
4XTECH-12>BEACON [09/20/07  19:18:53] <UI R>:
2 Users/8 Broadcasts ,
Uplink freq:145.890,145.850(AP),145.930,   1269.800, 1269.900

JE9PEL>APRS,4XTECH* [09/20/07  19:19:57] <UI R>:Hello
JE9PEL>APRS,4XTECH* [09/20/07  19:20:19] <UI R>:Hello via GO-32 APRS
JE9PEL>APRS,4XTECH* [09/20/07  19:20:48] <UI R>:Hello via GO-32 APRS
JE9PEL>APRS,4XTECH* [09/20/07  19:22:35] <UI R>:Hello via GO-32 APRS de JE9PEL
JE9PEL>APRS,4XTECH* [09/20/07  19:23:15] <UI R>:Hello via GO-32 APRS de JE9PEL
JE9PEL>APRS,4XTECH* [09/20/07  19:26:01] <UI R>:test succeeded
JE9PEL>APRS,4XTECH* [09/20/07  19:27:40] <UI R>:hello
JE9PEL>APRS,4XTECH* [09/20/07  19:28:19] <UI R>:Digipeat Test Succeeded
JE9PEL>APRS,4XTECH* [09/20/07  19:29:11] <UI R>:Digipeat Test Succeeded

------------------------------------------------------------------------------

受信レポート先 findu は、こちらです。
http://www.findu.com/cgi-bin/raw.cgi?call=4XTECH-12
UI-View32 プログラムにより、自動的にアップロードされます。
新しいデータは、そのページの下部に追加表示されていきます。

4XTECH-12>BBSTAT,qAO,JE9PEL:Open:AB1C23:
4XTECH-12>STATUS,qAO,JE9PEL:>B:22975921
4XTECH-12>BBSTAT,qAO,JE9PEL:Open:AB1C23:
4XTECH-12>STATUS,qAO,JE9PEL:>B:22976045
4XTECH-12>STATUS,qAO,JE9PEL:>B:22976169
4XTECH-12>BEACON,qAO,JE9PEL:>Sat Sep 22 23:36:44 2007 :UTC| Gurwin Techsat1B (V9.87)
4XTECH-12>BEACON,qAO,JE9PEL:BBS(V9.87 beta) 2Users/8BCasts.
4XTECH-12>BEACON,qAO,JE9PEL:Upl:145.89,145.93,1269.8,1269.9
4XTECH-12>BEACON,qAO,JE9PEL::BLN1 GO32:Test APRS!!Use pth via 4XTECH
4XTECH-12>BEACON,qAO,JE9PEL::BLN2 GO32:APRS msgs and clients use 145.85 Upl
4XTECH-12>BEACON,qAO,JE9PEL::BLN3 GO32:D7&D700 posits use 145.93
4XTECH-12>STATUS,qAO,JE9PEL:>B:22976647
4XTECH-12>BBSTAT,qAO,JE9PEL:Open:AB1C23:
4XTECH-12>BBSTAT,qAO,JE9PEL:Open:AB1C23:
4XTECH-12>STATUS,qAO,JE9PEL:>B:22976771
4XTECH-12>STATUS,qAO,JE9PEL:>B:22976895
4XTECH-12>BBSTAT,qAO,JE9PEL:Open:AB1C23:
4XTECH-12>STATUS,qAO,JE9PEL:>B:22977019
4XTECH-12>BEACON,qAO,JE9PEL:>Sat Sep 22 23:38:52 2007 :UTC| Gurwin Techsat1B (V9.87)
4XTECH-12>BEACON,qAO,JE9PEL:BBS(V9.87 beta) 2Users/8BCasts.
4XTECH-12>BEACON,qAO,JE9PEL:Upl:145.89,145.93,1269.8,1269.9
4XTECH-12>BEACON,qAO,JE9PEL::BLN1 GO32:Test APRS!!Use pth via 4XTECH
4XTECH-12>BEACON,qAO,JE9PEL::BLN2 GO32:APRS msgs and clients use 145.85 Upl

------------------------------------------------------------------------------

Subject: New 9600 baud mobile APRS satellite Access
From: Bob Bruninga
Date: Sun, 16 Sep 2007 11:58:43 -0400 (EDT)

The GO-32 Satellite TECHSAT-1B team has asked me to announce experimental
9600 baud APRS access for mobile and tactical APRS on a not-to-interfere
basis with the existing PACSAT BBS. 

The uplink is possible with 5 Watts on 2 meters, but the downlink is 9 dB
worse to an omni antenna on UHF and requires tuning 10 to 20 KHz for Doppler.
SO far, we are starting with zero permanent IGates to bring the downlink
into the global APRS system, but we hope volunteers will surface with
permanent satgates.  So initally, do NOT expect to see yourself on FINDU.COM.
Enjoy ham radio,  Make a contact instead!

Experimental testing shows that an APRS HT with a 19.5" whip can get a lucky
shot into this satellite (but not when there is congestion on the uplink).
With a handheld beam, it should be no problem for an HT, and the beam is
needed on reception anyway.  Fifty Watt mobiles should have no problem using
a stock mobile whip.  Due to the absence of APRS signals to date, we do not
have good statistics on reception in a mobile yet...

Operating on a 9600 baud FULL DUPLEX APRS satellite is MUCH different than
ARISS, or any of the other 1200 baud APRS PCSATS, because the turn-around
is so fast, that you cannot see your own digipeated packets on the same radio
(usually)...  Please read and understand this entire email before attempting
to operate.

The easiest way to get on GO-32 with 9600 baud APRS is to use a Kenwood D7,
D700 or D710 radio.  These radios since 1998 have been satellite 9600 baud
ready, just waiting on a satellite!.

Read these notes on how to operate GO-32 with a D7 or D700:

Set APRS Baudrate to 9600 baud. 
Set A band to uplink on 145.93
Set B band to receive 435.225 +/- 10 KHz
Set Path to be via 4XTECH
Set MYCALL to a unique SSID
Set TX method to AUTO
Set TX RATE 1 min for HT. 2 min for D700
Put something useful in your STATUS text maybe describing your setup:
"50W mobile, 1/4 wave, 2m rate" or "5W HT, long whip, 1m rate"

Save in a PM for use anytime you are outside of the terrestrial APRS network.

SATELLITE OPERATING NOTES:

The GO32 uplinks and downlinks are for the PACSAT store and forward system
and users.  APRS is on a secondary basis and should not be operated
unattended.  If you see that the BBS PBLIST is full of other users, do not
enable your APRS since the uplink will be busy.  RIght now, the PBLIST is
not in APRS format so you cannot see it unless you are running normal packet
mode.  But we will work on that...

On the D700 you can press PMON on the front panel and see these packets...
but they FLY by...

ACCESS TIMES:  GO-32 is sun synchronous and so it comes over everywhere
three times between about 8 AM to Noon and again between 8 PM to midnight
local sun time.  During these two windows at least one pass each will be
an overhead pass which might also work for an HT.  The other passes will
be lower to the East or West and will work fine for a 50W mobile.

WHAT YOU HEAR:  9600 baud sounds almost exactly like open squelch, though
the tuned ear can soon distinguish the difference.  Before the pass, set
your squelch normally to quiet the speaker.  When you hear the satellite,
the squelch will open and you may see up to 3 bars on your S meter.
Tune to the "best sounding" noise.

DOPPLER:  Depending on how low to the horizon you can see, the satelite
approaches 10 KHz high at 435.235 MHz... But it is maybe 3000 km away.
As it gets higher, and 6 dB closer, it will be on 435.230 MHz, passing 
through 435.225 published center frequency at the middle point, and then
drop down through 435.220 and ending at 435.215.

But since it is 6 to 10 dB closer (and stronger) towards the center of
the pass (800 km overhead), the mobile antenna is probably only going to
hear the middle 435.230, .225, .220 portion easily.
So I would start my receiption at 435.230...

UPLINK CHANNELS:  GO-32 allows two APRS uplinks.  One is exclusive to
D7/D700 tactical position reporting and the other exclusive to messaging.
This is in hardware, not policy...

1) All APRS messaging (or fixed station non-Mic-E positions) must use the
145.85 uplink where GO32 only digipeats APRS packets with TOCALLs that begin
with the usual "APxxxx".  (Even the D7 and D700 use "APKxxx" for messages.)
 
2) All APRS Mic-E position uplinks (D7, D700 and D710s) must be on 145.93
MHz and they must have the position comment set to "Committed, Special or
PRIORITY"...  With those comment settings then the TOCALL first LATITUDE
digit will be 1,2,3,4,5,6,7 and only these will be accepted by GO32 for
digipeating from 145.93.

DATA CARRIER DETECT: The D700 and non(g) model D7's will NOT TX if they
are hearing the downlink at the same time due to CARRIER DETECT.  The D7(g)
model has DCD IGNORE that *will* let it TX anyway.  So use separate rigs
for TX and for RX if you want to see yourself.

Otherwise stick to the receommended TX rates and know that you are getting
in if you stick to the protocol.  Sticking to the recommended rates also
keeps channel loading low, so that everyone gets in with less congestion.

PERMANENT SATGATES:  Here is a great place to use your D7 HT when you are
not using it otherwise.  Simply connect it to a 19" whip over a ground
plane and to your APRS IGate system.  The antenna does not even need to
be high, since it cannot hear, nor will it be on frequency for low packets
near the horizon 3000 km away.  Set it to 9600 baud RX and tune to 435.230
(which is 5 KHz high).  This Doppler setting will match the stronger signals.

This 19.5" whip (3/4 wave on 435) does not need to see below 25 degrees,
since its max gain (almost 7 dB) is between 30 to 70 degrees anwyay.
This also protects your HT from lightning, since it can be low, below all
of your other antnenas.  Yes, your station will only see about 30% of all
possible packets and only on the best two passes per day, but combined with
dozens of other such unattended SATgates, all packets should be heard
somewhere by someone and injected into the APRS Internet system.

I hope to have an APRS-via-GO32 web page up in a few weeks, but in the
mean time, use this message for deails.

Here is a link to AMSAT's description of GO-32:

http://www.amsat.org/amsat-new/satellites/satInfo.php?satID=14&retURL=/satellites/status.php

Good luck!

Bob, Wb4APR


http://www.ew.usna.edu/~bruninga/GO32-ops.html


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