APRS UK Network

Focusing on the development of the APRS network in the UK

  • Adventures in LoRa APRS (70cms), After reading and watching the following:

    RSGB RadCom (RSGB Membership Required)

    SOTA Reflector

    YouTube Tech Minds

    Now in Telford, Shropshire

    I have my LoRa APRS IGATE up and running on 439.9125 MHz (BW125, SF12, CR5) and have received my first few packets

    This is in addition to my existing 2m (144.800 MHz) FM Packet Radio (AX.25) IGATE station

    I have also setup a syslog server on my raspberry PI (which is running my 2m FT8 station) so I can stream the received data and runtime activity of the embedded IGATE software, to a log file.

    My M54 LoRa APRS Coverage

    I was able to receive a mobile station across the full length of the M54 and have plotted the signal to noise values from west of Shrewsbury out to Essington nr Wolves, see below:

    plotted the signal to noise values from west of Shrewsbury out to Essington nr Wolves

    I continued to receive packets beyond Walsall albeit they were corrupted, due to incomplete reception.

    I've done a bit more analysis of my LoRa APRS receiver as well as playing with various bandpass filters and pre-amps to try and improve the sensitivity of the receiver (albeit to no avail). My radio range seems to max out at around 45 miles in a very narrow direction (which is probably down to the relatively low sighting of my co-linear)

    My latest data analysis is below and illustrates how the LoRa APRS radio decodes a few more packets overnight than in the daytime (I'm assuming that this is due to the local noise environment (floor) being reduced overnight and / or a reduction in transmissions within the 70cms band, also at this time)

    Plot of decodes to failed decodes for LoRa APRS packets received at this location over a 6 week ish period Plot of error rates related to LoRa APRS packet decoding