APRS Digipeater

MB7VB is an APRS Digipeater located in Margate, Kent.

The digipeater consists of a 8 Amp linear PSU, a Motorola GM340 VHF radio, a USB soundcard adapter, a Raspberry Pi3, and a 5v relay board driven by the Pi’s GPIO pins for PTT switching. The digipeater is mounted on a 19″ 1U rackmount shelf.

The Raspberry Pi is running Direwolf as the APRS application.

The antenna is a Diamond VX30 dipole mounted at 43 metres above ground level, and is feed via a 2 metre bandpass filter and a VHF/UHF diplexer. ERP is calculated at 2 Watts.

Users can access the digipeater on 144.800Mhz (no CTCSS tone) which is the UK, and Europe, wide APRS frequency. Only valid APRS packets are digipeated.

Path Settings

MB7VB is set to digipeat valid packets received on rf with the following path aliases:

Wide1-1
Wide1-1, Wide2-1
Wide1-1, Wide2-2
Wide 2-1
Wide 2-2

Any other paths e.g. RELAY, Wide1-2, Wide2-3, Wide3-1 etc are trapped by the logic and will not be digipeated.

MB7VB will accept paths that go through specific digipeaters such as: MB7VB, F1ZVV.

Additional Information

Any packets which have passed through the internet (i.e. the packet contains “TCPIP”) are not digipeated.

TRIG suggests that local user’s maximum beacon rate should be set at no more than 1 beacon per minute, ideally much less frequent, and with smartbeaconing enabled.

If any local users are considering setting up an APRS igate TRIG respectfully requests that they make contact to enable co-ordination for best performance of the APRS network in Thanet and beyond.

Links

These resources are only available to TRIG members.