This feature is currently inactive as was no longer getting used.

 

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 GB3IP.

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 http://www.elcom.gr/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.

The other way to use the TinyTrak on GB3DC is to let it send out smart beacons when the repeater is not in use by voice stations. This makes for a much more accurate plot on the map as it is not dependant on when the operator dekeys. the only thing you must ensure is that you have wired the tinytrak in such a way that it can detect when there is voice traffic on the repeater so it can suspend beacons until the repeater is free. You must also ensure if using this mode you do not encode any CTCSS as this will open the repeater for voice traffic unnecessarily.

This site was last updated Friday, 22 January 2021