[amsat-bb] How to digipeat? (one digi call)

[Robert Bruninga]

Slight correction:

> UNPROTO CQ VIA <satellite-callsign> such as CQ VIA ARISS, RS0ISS, PSAT,
LU7AA-1, etc.

Can be confusing.  The digipeater path <satellite callsign> should only
have one callsign in it.  Either the desired digipeating satellite's call,
or the generic ARISS or APRSAT.  There is no value to putting in more than
one, it only makes the packet longer and will never get executed. *

*Unless you are trying for a LIVE -dual HOP experiment.  Then both
satellites have to be in view and you must get the sequence in the right
order as to which one is closer. Etc.   The probability is so low, it is
not worth burdening the 99.999% of your packets with two hops when 0.0001
might be successful.  So far, in 4 years I have still not seen a single
successful dual hop.

Bob


-----Original Message-----
From: AMSAT-BB <amsat-bb-bounces at amsat.org> On Behalf Of JoAnne Maenpaa
via AMSAT-BB
Sent: Sunday, September 8, 2019 10:55 AM
To: 'AMSAT-BB' <amsat-bb at amsat.org>
Subject: Re: [amsat-bb] How to digipeat?

I thought I'd toss out a few more hints to help folks trying to figure out
how to get UISS to speak satellite packet. This is pretty much UISS
specific detail. Make sure you have your station setup the way Scott and
Hans have discussed.

Setup your TNC with the MYCALL command. When you setup UISS the call sign
you enter during setup will be your MYCALL parameter.

Most of 145.825 MHz digipeater satellites use the AX.25 UI protocol You
setup this protocol with the command:

UNPROTO CQ VIA <satellite-callsign> such as CQ VIA ARISS, RS0ISS, PSAT,
LU7AA-1, etc.

You can enter these parameters in UISS in the top-left of the screen in
the "To" and "Via" windows. Set "To:" as CQ and "Via" as the call sign of
the satellite you are working.

In the UISS 'Tx Text' window (the top text windows) enter:
=Lat/Long-Message-to-digipeat -or- in my case near Chicago I use:
=4211.29N/08827.08W-Greetings :-)  You need the = and - in your message
string. The dash displays your icon as the house on the map.

To transmit your packet to the satellite click on the UISS Text/Data
button and this should then trigger your transmitter. Folks use vari- ous
combinations of PTT controls or VOX to trigger their transmitter
- use whatever works for you.

The shorter your message the better chance you have of getting digi-
peated if lots of stations are causing packet collisions.

Additional terrestrial packet routes such as WIDE1-1, WIDE2-1, etc.
are not useful for space digipeating. Your target is the APRS satel- lite
on 145.825 not the terrestrials on 144.390. The satellite digi- peats to
us earthlings (and the SatGates) listening on 145.825. You aren't trying
to tell every APRS station on 144.390 within hundreds of miles where you
are driving.

Adding all the WIDE strings also has the effect of making your packet
longer, decreasing your success of getting digipeated on a busy pass.

A lot of UISS setups document using AGWPE for your packet modem. This is a
tried and true packet engine. Many of found that the UZ7HO soft- ware
packet modem gives better performance especially when receiving.
Your software packet modem will expect to receive the entire packet
transmission with no errors - the correct checksum for it to be dis-
played on your computer. Often you hear "good sounding" packets but if you
aren't receiving the whole kahuna with correct checksum you won't get the
message displayed. The same generally applies to the SatGate stations
listening to the activity and gating it on to the web.

The UISS program will require settings to be changed to operate with UZ7HO
Soundmodem: In UISS top menu select Setup -> UISS -> LAN Click 'Enable LAN
Mode'

In LAN setup click on 'Enable LAN Mode' Host 127.0.0.1 AGWPort 8000

UISS may ask you to restart, go ahead and restart UISS.

For normal operation start the UZ7HO Soundmodem first. Then start UISS.
When both programs are running UISS will show it has connected with the
Soundmodem:

  Connected to server 127.0.0.1
  Port1 with Soundcard Ch: A;

--
73 de JoAnne K9JKM
k9jkm at amsat.org



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