My APRS iGate, 2E0RLZ-10

The Automatic Packet Reporting System (APRS) is a way to share local information of immediate value in real time. This information is often the position of its users, but can also include short messages and announcements, telemetry data like weather reports and storm forecasts.

You don’t need the internet to use it, so it doesn’t rely on there being a good mobile phone signal wherever you happen to be. Instead, it uses established packet radio protocols on various amateur bands. A handheld transceiver can receive information packets for a computer to decode and display, and also send encoded packets out for others to receive on the same shared frequency. A network of digital repeaters re-transmit the message, transporting it further than the handheld transceiver can reach. Internet-connected receivers, called iGates, also collect the data and relay it into the APRS Internet System (APRS-IS) to appear on sites like aprs.fi.

2E0RLZ-10 is one such iGate. It is an attempt to improve APRS coverage in South London.

You can make one yourself using an SDR dongle and a Raspberry Pi. It is fairly easily done since there is a SD card image available which requires little configuration to get things going. The result is a Direwolf-based APRS decoder which sits and listens to the APRS frequency via the SDR dongle. Thanks to aprs.fi, you can see from where 2E0RLZ-10 is hearing stations. The antenna is a Yagi pointing at a bearing of about 80°. This explains why there are a fair number of stations being heard in East London. For stations travelling through the centre of London, for example the City of London, 2E0RLZ-10 can be seen working together with M0HSL-10, just over 4km away.

The Raspberry Pi I use was kindly lent to me by Jeff Belcher. Thanks Jeff!

The location isn't quite right, because I didn't want to give out my exact location. The coordinates given are under 500m from the station, 51.495000, -0.100556 ≈ 51° 29′ 42″ N, 0° 6′ 2″ W ≈ Maidenhead IO91WL. Aptly, these refer to a point on the site of the Michael Faraday Memorial.