GB3DC is now enabled for
for APRS. This enables people who wish to participate in APRS send their
positional information to the repeater and it will be uploaded to the
internet. APRS is a system developed by Bob Bruninga, WB4APR that allows
radio hams to transmit and receive position reports over the radio.
Traditionally APRS is
used simplex on 144.800MHz in the uk. It was when myself and Ken G7RXG
became interested in playing with APRS that we realized there was no
network as such in the East Midlands. The next obvious thing for us to try
on our quest for APRS would be to provide our own IGate to upload our
received APRS signals to the internet. This would cause further problems
as I was unable to provide this kind of service from here as the
transmitter on GB3DC would certainly kill any further 2m reception on
144.800. Ken is also not in a position to provide this kind of facility as
he does not have or want any external antennas on his house.
This got me thinking
that I could utilize the excellent receiver on GB3DC for this when not in
use for voice traffic. After thinking about this for a while I became
aware of a proposed experiment in Staffordshire on the GB3IP
repeater to enable their repeater for APRS. Looking at their website
www.gb3ip.org.uk I learnt of
several additional methods of integrating APRS into a voice repeater.
I then approached Ofcom
& the RSGB Repeater Management Committee with my proposals to experiment
with APRS on GB3DC. They were ok with the concept in principal and granted
permission for experimentation to take place so long as users were not
expected to send APRS in a different way to the way it will be sent to
It then took just over a
week to enable APRS reception on GB3DC with an old TNC left over from the
days I used to run GB7OAK. I decided to steer away from the usual APRS
IGate software (UIView) and try the more upto date software written by
George Rossopoulos SV2AGW
Mobile I am using a
TinyTrak3+ GPS Position Encoder
http://www.byonics.com/tinytrak These are really neat and tidy little
units from the US.
These are available for
a little as £25-£30 as a kit or pre assembled and when coupled to your GPS
- SatNav & 2m transceiver will
provide you with all you need to get on APRS. No need to buy one of them
expensive APRS enabled mobiles like the Kenwood TMD-700e
These can be configured
to send a short 300ms Data Burst at the end of a regular voice
transmission. When used on GB3DC this Data Burst is decoded and uploaded
to the internet. This allows anyone anywhere
looking at a website to plot your exact location on a map. The plots
will appear as dots on the map at the exact point when you dekey the PTT.
It is great fun to see the exact route a station takes to work for
example. Have a play with the example below.