– Radio at EMF Camp – LoRa APRS Gateway MB7ULG

MB7ULG is a LoRa Gateway connected to the APRS-IS netwoek

  • Call Sign: MB7ULG
  • Location: EMF Camp – Eastnor Castle (IO82TA)
  • Mode: Lora
  • Band: 70CM
  • Output Frequency: 439.9125 MHz
  • Output Power: -10 dbW (100mW)
  • Input Frequency: 439.9125 MHz
  • Spreading Factor: 12
  • Bandwidth 120KHz

The gateway supports both APRS-IS tunnelling and native AX25 payloads and is provided by the Northern Quarter

About LoRa

LoRa is a wideband low power protocol often used in the 868 ISM band which uses a relatively slow scanning carrier frequency termed “chirp spread spectrum” though I have also heard it called “sliding FM”.

The motivation in bringing this gateway / technology to EMF and operating it in Amateur spectrum is to demonstrate a crossover between Amateur and IOT and hopefully generate interest on both sides

Hardware is cheap and readily available with the LillyGo T-Beam units being particularly popular. If you want to try it then make sure you order a 433MHz unit ideally with GPS and OLED screen, the newer version has 3 push buttons along the bottom edge of the pcb and can be found on sites such as AliExpress or Ebay and enclosure designs are available on thingiverse

The firmware currently being tried on the T-Beam can be found at: .

https://github.com/SQ9MDD/TTGO-T-Beam-LoRa-APRS

If you wish to build a gateway on a raspberry pi and test your T-Beam before arriving at EMF I am using the following iGate software because it it supports both native AX25 and the TNC2 tunneling protocol used by a lot of the current implementtions;

https://github.com/IZ7BOJ/RPi-LoRa-KISS-TNC

There is more useful background in the following blog:

https://iz7boj.wordpress.com/