APRS Station

We have had our APRS Station operating for a while now and it has been performing well. We decided to install a dedicated antenna on our tower that is a bit better matched to supporting our APRS Station. We choose a Diamond X50NA antenna and installed it on our tower at the 70 ft level using a vertical antenna bracket. The Diamond X50NA antenna has a broader vertical pattern than out existing repeater access antenna (a Diamond X300NA). The Diamond X50NA antenna is installed 19″ from the tower leg to minimize any interactions with the tower structure on the 2m band.

APRS Antenna On Tower

I also decided to move our APRSISCE/32 Software which controls our APRS Station to our home server which is always on.

Home Server

The APRSISCE/32 software implements an iGate function (sending APRS packets to internet-based APRS servers) so it performs a critical role as part of our APRS Station’s operation. The following is a time-lapse video which shows about 6 minutes of the APRSISCE/32 software’s operation. The yellow lines show the paths taken by packets through various APRS Digipeaters on their way to the internet via our iGate. The circle on the map in the video is about 180 mi (290 km) in diameter. As you can see in the video, we are handing packets from New Hampshire, USA as well as from several surrounding states in New England. It is interesting to see the paths that some APRS packets follow as they find their way to the internet via our iGate node. It is quite apparent when there is an improvement in 2m propagation as we begin to see packets arriving from much greater distances.

The connection between our APRS transceiver (a Kenwood D-710A) and our home server is implemented via an RS-232 over TCP/IP device from StarTech. This device allows us to run the RS-232 control connection from the APRS transceiver to our home server over the wired Ethernet LAN installed in our home.

RS232 Over TCP/IP Device

With these steps, our APRS Station is complete. We are currently iGate’ing about 7,500 packets per month to the internet. You can see some real-time information on the performance of our station by clicking here.

– Fred (AB1OC)