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[aprssig] New APRS

Keith - VE7GDH ve7gdh at rac.ca
Sat Dec 10 07:08:42 UTC 2005

Fred WB4AEJ wrote on Dec 9 2005

> I am working on a project to create an APRS node here in the Sylva,
> NC area.  Hoping to get information that will help our project
> along.
> We are looking into getting an Internet feed to the site so we can
> dump data to the findu.com server over the Internet.
> Besides a two meter rig, TNC, power supply, and an antenna, what
> additional hardware would we need to be able to feed data over a
> high speed Internet connection?

The IGate does of course need an Internet connection. As others
mentioned, there is no need to have the IGate at the digipeater site,
but if you have a connection there, there's nothing wrong with that.
James suggested Xastir for the IGate. Nothing wrong with that, but
keep UI-View32 in mind as well. www.ui-view.org. You might prefer a
Linux-based IGate, but you will probably find that UI-View32 a lot
easier to set up first time around. It can use almost any TNC, but one
that can run KISS would be needed if it was also going to be running
as a digipeater. Even the oldest KPC3 (non plus version) or even a
KPC2 would be fine for KISS mode. If the IGate and digipeater are at
the same site, you would only need one radio and one TNC. A TNC2
clone that can handle KISS would be fine, but the KPC has very low
current consumption. If the IGate and digipeater are at different
locations, you would need two radios & two TNCs. If it's a stand-alone
digipeater, the smarts are in the TNC. If there is a computer running
the show, then you could have something like UI-View32 running on
the computer and it could provide a more intelligent digipeater than
the TNC-only digipeater could.

As others have mentioned, you don't connect the IGate to findu.com.
You connect to an APRS server. The findu.com site gets data from
one of the APRS servers. The findu.com site is a very handy one to
retrieve APRS data that has made it to an IGate. If you have a
computer and an even a slow Internet connection, you can make use of
findu.com. How fast a connection you need for the IGate is dependent
on how much data is flowing in each direction. I'm sure there are
IGates getting by on a dial-up connection, but most have a faster one.

A fairly new Kantronics KPC-3+ should do the job for a stand-alone
digipeater. Version 8.3 or newer would be OK, but version 9.1 is the
latest and most up-to-date version.  All you need at the digipeater
site is the radio & antenna and the cable(s) to connect the TNC to the
radio, and of course a power supply. You only need a computer for
programming the TNC. See www.nwaprs.info for some suggested settings.
The KPC-3+ is not the only way to go. You could ask on the list about
UIDIGI and replace the ROM in a suitable TNC. You could also have a
computer-based digipeater with DIGI_NED. I'm not sure if it's the home
page, but you can find it at http://www.qsl.net/digi_ned.

AJ3U mentioned the "fix 144.390" page at
http://web.usna.navy.mil/~bruninga/aprs/fix14439.html. If you can't
browse to that site (DNS problems) there is a mirror at
http://webs.lanset.com/wa8lmf/~bruninga/index.htm. His suggestion
about contacting other hams in the area that are already involved in
APRS is a very good one. There is nothing wrong with setting up a
properly configured IGate even if there is already one in the area,
but you wouldn't want to go and put in a digipeater where it wasn't
needed. It may take a bit of discussion to determine if your proposed
digipeater site will help or hinder APRS in your area. If there isn't
a digipeater within earshot of your proposed location, then by all
means put one in. However, if there are already several in the area,
you would want to determine if another digipeater is really needed or
not. If the proposed site has a bit of elevation, and there aren't any
other WIDEn-n digis around, put one in. If there are already WIDEn-n
digis in the area, consult with the hams already running APRS in your
area. If your proposed location is hemmed in by hills but could be
heard by WIDEn-n digis at a higher location, then a WIDE1-1 only digi
might be a good thing for the location. Again, talk to the "locals"
and see what is needed. I'm sure they will welcome your group, but
make sure APRS will work better and not worse if you add another digi.

All of the above was written before I looked at Sylvan NC. I watched 
your area for about 20 minutes using UI-View. There is a screenshot 
(94 KB) at www.ui-view.org/images/sylvan-nc.png. The nearest digis 
that I could see were about 50 KM to the northwest, 60 KM to the west, 
and about 85 KM to the southeast. I spotted a couple of IGates about 
90 KM to the east and to the southeast. At a glance, I would think 
that adding a digi with some elevation & IGate at Sylvan would 
probably work out very well. You could even just listen on 144.390 MHz 
and see how much activity there is already in the area.

73 es cul - Keith VE7GDH
"I may be lost, but I know exactly where I am!"

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