[amsat-bb] How to digipeat?

[JoAnne Maenpaa]

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